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1. Utilization of convolutional neural networks for H I source finding

Author

Henrik Håkansson, Anders Sjöberg, Maria Carmen Toribio, Magnus Önnheim, Michael Olberg, Emil Gustavsson, Michael Lindqvist, Mats Jirstrand, and John Conway

Subjects
Space and Planetary Science, Astronomy and Astrophysics
Abstract

Context. The future deployment of the Square Kilometer Array (SKA) will lead to a massive influx of astronomical data and the automatic detection and characterization of sources will therefore prove crucial in utilizing its full potential. Aims. We examine how existing astronomical knowledge and tools can be utilized in a machine learning-based pipeline to find 3D spectral line sources. Methods. We present a source-finding pipeline designed to detect 21-cm emission from galaxies that provides the second-best submission of SKA Science Data Challenge 2. The first pipeline step was galaxy segmentation, which consisted of a convolutional neural network (CNN) that took an H I cube as input and output a binary mask to separate galaxy and background voxels. The CNN was trained to output a target mask algorithmically constructed from the underlying source catalog of the simulation. For each source in the catalog, its listed properties were used to mask the voxels in its neighborhood that capture plausible signal distributions of the galaxy. To make the training more efficient, regions containing galaxies were oversampled compared to the background regions. In the subsequent source characterization step, the final source catalog was generated by the merging and dilation modules of the existing source-finding software SOFIA, and some complementary calculations, with the CNN-generated mask as input. To cope with the large size of H I cubes while also allowing for deployment on various computational resources, the pipeline was implemented with flexible and configurable memory usage. Results. We show that once the segmentation CNN has been trained, the performance can be fine-tuned by adjusting the parameters involved in producing the catalog from the mask. Using different sets of parameter values offers a trade-off between completeness and reliability.

Published
2023

2. Monitoring of the temporal evolution of water vapor in the stratosphere of Jupiter with the Odin space telescope between 2002 and 2019

Author

Paul Hartogh, Thibault Cavalié, Bilal Benmahi, Michel Dobrijevic, Raphael Moreno, Nicolas Biver, Alain Lecacheux, Thierry Fouchet, Emmanuel Lellouch, Aage Sandqvist, Åke Hjalmarson, Vincent Hue, Kenneth Bermudez Diaz, Urban Frisk, Michael Olberg, and F. Billebaud

Subjects
Jupiter, Spitzer Space Telescope, Astronomy, Environmental science, Stratosphere, Water vapor
Abstract

In July 1994, comet Shoemaker-Levy 9 collided with Jupiter. This has introduced new chemical species into Jupiter’s atmosphere, notably H2O. We observed the disk-averaged emission H2O in Jupiter’s stratosphere at 556.936 GHz between 2002 and 2019 with the Odin space telescope with the initial goal of better constraining vertical eddy mixing (Kzz) in the layers probed by our observations (0.2-5 mbar). The Odin observations show a decrease of about 40% of the line emission from 2002 to 2019. We analyzed these observations by combining a 1D photochemical model with a radiative transfer model to constrain the vertical eddy diffusion Kzz in the stratosphere of Jupiter. We were able to reproduce this decrease by modifying a well-established Kzz profile, in the 0.2 mbar to 5 mbar pressure range. However, the Kzz obtained is incompatible with observations of the main hydrocarbons. We found that even if we increase locally the initial abundances of H2O and CO at impact, the photochemical conversion of H2O and CO to CO2 does not allow us to find the observed decrease of the H2O emission line over time, suggesting that there is another loss mechanism. We propose that auroral chemistry, not accounted for in our model, as a promising candidate to explain the loss of H2O seen by Odin. Modeling the temporal evolution of the chemical species deposited by comet SL9 in the atmosphere of Jupiter with a 2D photochemical model would be the next step in this study.

Published
2020

3. LOFAR4SpaceWeather (LOFAR4SW) – Increasing European Space-Weather Capability with Europe’s Largest Radio Telescope: Beyond the Detailed Design Review (DDR)

Author

Michael Olberg, Mark Ruiter, Joris Verbiest, Peter T. Gallagher, Michael Lindqvist, Rene C. Vermeulen, Nicole Vilmer, Eoin P. Carley, Stuart C. Robertson, Maaijke Mevius, Carla Baldovin, Mario M. Bisi, David G. Barnes, Paulus Krüger, Barbara Matyjasiak, Tobia Carozzi, Hanna Rothkaehl, and Richard Fallows

Subjects
Radio telescope, Engineering, business.industry, Space weather, business, Telecommunications, Design review
Abstract

The Low Frequency Array (LOFAR) is an advanced phased-array radio-telescope system based across Europe. It is capable of observing over a wide radio bandwidth of ~10-250 MHz at both high spatial and temporal resolutions. LOFAR has capabilities that enable studies of many aspects of what we class as space weather (from the Sun to the Earth and afar) to be progressed beyond today’s state-of-the-art. However, with the present setup and organisation behind the operations of the telescope, it can only be used for space-weather campaign studies with limited triggering availability. This severely limits our ability to effectively use LOFAR to contribute to space-weather monitoring/forecast beyond its core strength of enabling world-leading scientific research. LOFAR itself is made up of a dense core of 24 stations near Exloo in The Netherlands with an additional 14 stations spread across the northeast Netherlands. In addition to those, there are a further 13 stations based internationally across Europe. These international stations are, currently, six in Germany, three in northern Poland, and one each in France, Ireland, Latvia, Sweden, and the UK. Further sites are under preparations (for example, in Italy). We are undertaking a Horizon 2020 (H2020) INFRADEV design study to undertake investigations into upgrading LOFAR to allow for regular space-weather science/monitoring observations in parallel with normal radio-astronomy/scientific operations. This project is called the LOFAR For Space Weather (LOFAR4SW) project (see: http://lofar4sw.eu/). Our work involves all aspects of scientific and engineering work along with end-user and political engagements with various stakeholders. This is with the full recognition that space weather is a worldwide threat with varying local, regional, continent-wide impacts, and also global impacts – and hence is a global concern. Here, we summarise the most-recent key aspects of the LOFAR4SW progress including outputs/progress following the Detailed Design Review (DDR) that took place at ASTRON, The Netherlands, in March 2020, as well as the implementation of recommendations from the earlier Preliminary Design Review (PDR) with an outlook to the LOFAR4SW User Workshop the week following EGU 2020. We also aim to briefly summarise a key set of the longer-term goals envisaged for LOFAR to become one of Europe’s most-comprehensive space-weather observing systems capable of shedding new light on several aspects of the space-weather system, from the Sun to the solar wind to Jupiter and Earth’s ionosphere.

Published
2020

4. Monitoring of the evolution of H2O vapor in the stratosphere of Jupiter over an 18-yr period with the Odin space telescope

Author

Emmanuel Lellouch, R. Moreno, Paul Hartogh, Aa. Sandqvist, Urban Frisk, K. Bermudez-Diaz, Alain Lecacheux, N. Biver, Thierry Fouchet, Å. Hjalmarson, Michel Dobrijevic, Bilal Benmahi, Vincent Hue, Thibault Cavalié, Michael Olberg, F. Billebaud, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), ASP 2020, Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), ASP 2019, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Swedish Space Corporation (SSC), Onsala Space Observatory, Chalmers University of Technology [Göteborg], and The Odin Team

Subjects
planets and satellites: atmospheres, Physics, 010504 meteorology & atmospheric sciences, Comet, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], submillimeter: planetary systems, Astronomy and Astrophysics, Context (language use), Astrophysics, planets and satellites: individual: Jupiter, 01 natural sciences, Jovian, Eddy diffusion, Jupiter, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Radiative transfer, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Stratosphere, ComputingMilieux_MISCELLANEOUS, Water vapor, 0105 earth and related environmental sciences
Abstract

Context. The comet Shoemaker-Levy 9 impacted Jupiter in July 1994, leaving its stratosphere with several new species, with water vapor (H2O) among them. Aims. With the aid of a photochemical model, H2O can be used as a dynamical tracer in the Jovian stratosphere. In this paper, we aim to constrain the vertical eddy diffusion (Kzz) at levels where H2O is present. Methods. We monitored the H2O disk-averaged emission at 556.936 GHz with the space telescope between 2002 and 2019, covering nearly two decades. We analyzed the data with a combination of 1D photochemical and radiative transfer models to constrain the vertical eddy diffusion in the stratosphere of Jupiter. Results. Odin observations show us that the emission of H2O has an almost linear decrease of about 40% between 2002 and 2019. We can only reproduce our time series if we increase the magnitude of Kzz in the pressure range where H2O diffuses downward from 2002 to 2019, that is, from ~0.2 mbar to ~5 mbar. However, this modified Kzz is incompatible with hydrocarbon observations. We find that even if an allowance is made for the initially large abundances of H2O and CO at the impact latitudes, the photochemical conversion of H2O to CO2 is not sufficient to explain the progressive decline of the H2O line emission, which is suggestive of additional loss mechanisms. Conclusions. The Kzz we derived from the Odin observations of H2O can only be viewed as an upper limit in the ~0.2 mbar to ~5 mbar pressure range. The incompatibility between the interpretations made from H2O and hydrocarbon observations probably results from 1D modeling limitations. Meridional variability of H2O, most probably at auroral latitudes, would need to be assessed and compared with that of hydrocarbons to quantify the role of auroral chemistry in the temporal evolution of the H2O abundance since the SL9 impacts. Modeling the temporal evolution of SL9 species with a 2D model would naturally be the next step in this area of study.

Published
2020

5. SEPIA - a new single pixel receiver at the APEX Telescope

Author

Magnus Strandberg, A. Koops, Michael Olberg, J. Barkhof, Igor Lapkin, Pavel A. Yagoubov, Parisa Yadranjee Aghdam, John Conway, T. Klein, Sascha Krause, Alexey Pavolotsky, W. Boland, Andrey M. Baryshev, Per Bergman, Erik Sundin, E. De Beck, J. P. Pérez-Beaupuits, Hans Olofsson, Ronald Hesper, M. E. Bekema, K. Torstensson, Bhushan Billade, F. M. Montenegro-Montes, C. De Breuck, Vincent Desmaris, S. Shafiee, J. Adema, Sven-Erik Ferm, Victor Belitsky, K. Immer, Hawal Rashid, Mathias Fredrixon, Denis Meledin, Andrey B. Ermakov, and Astronomy

Subjects
CIRCUMSTELLAR ENVELOPES, FOS: Physical sciences, Astrophysics, 01 natural sciences, law.invention, Telescope, Optics, Onsala Space Observatory, law, 0103 physical sciences, 010306 general physics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Physics, Noise temperature, Sideband, instrumentation: detectors, business.industry, Astronomy and Astrophysics, REGIONS, Polarization (waves), Dual-polarization interferometry, Intermediate frequency, WATER-VAPOR, Space and Planetary Science, business, Astrophysics - Instrumentation and Methods for Astrophysics, techniques: spectroscopic, Communication channel
Abstract

Context: We describe the new SEPIA (Swedish-ESO PI Instrument for APEX) receiver, which was designed and built by the Group for Advanced Receiver Development (GARD), at Onsala Space Observatory (OSO) in collaboration with ESO. It was installed and commissioned at the APEX telescope during 2015 with an ALMA Band 5 receiver channel and updated with a new frequency channel (ALMA Band 9) in February 2016. Aims: This manuscript aims to provide, for observers who use the SEPIA receiver, a reference in terms of the hardware description, optics and performance as well as the commissioning results. Methods: Out of three available receiver cartridge positions in SEPIA, the two current frequency channels, corresponding to ALMA Band 5, the RF band 158--211 GHz, and Band 9, the RF band 600--722 GHz, provide state-of-the-art dual polarization receivers. The Band 5 frequency channel uses 2SB SIS mixers with an average SSB noise temperature around 45K with IF (intermediate frequency) band 4--8 GHz for each sideband providing total 4x4 GHz IF band. The Band 9 frequency channel uses DSB SIS mixers with a noise temperature of 75--125K with IF band 4--12 GHz for each polarization. Results: Both current SEPIA receiver channels are available to all APEX observers., Accepted for publication in Astronomy & Astrophysics

Published
2017

6. Vibrationally excited water emission at 658 GHz from evolved stars

Author

Malcolm Gray, C. De Breuck, K. Torstensson, Elizabeth Humphreys, Alain Baudry, Michael Olberg, A. M. S. Richards, Wouter Vlemmings, Fabrice Herpin, FORMATION STELLAIRE 2018, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), Onsala Space Observatory, Dept. of Radio and Space Science, Chalmers University of Technology, Chalmers University of Technology [Göteborg], Jodrell Bank Centre for Astrophysics (JBCA), University of Manchester [Manchester], and European Southern Observatory [Santiago] (ESO)

Subjects
FOS: Physical sciences, Rotational transition, stars [Submillimeter], stars: AGB and post-AGB, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, law.invention, masers, law, 0103 physical sciences, Asymptotic giant branch, Astrophysics::Solar and Stellar Astrophysics, Masers, Emission spectrum, Maser, 010306 general physics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Line (formation), Physics, supergiants, Astronomy and Astrophysics, AGB and post-AGB [Stars], submillimeter: stars, Stars, Supergiants, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Excited state, Supergiant, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

Several rotational transitions of water have been identified toward evolved stars in the ground vibrational state as well as in the first excited state of the bending mode. In the latter vibrational state of water, the 658 GHz J = 1_1,0-1_0,1 rotational transition is often strong and seems to be widespread in late-type stars. Our main goals are to better characterize the nature of the 658 GHz emission, compare the velocity extent of the 658 GHz emission with SiO maser emission to help locate the water layers and, more generally, investigate the physical conditions prevailing in the excited water layers of evolved stars. Another goal is to identify new 658 GHz emission sources and contribute in showing that this emission is widespread in evolved stars. Eleven evolved stars were extracted from our mini-catalog of existing and potential 658 GHz sources for observations with the APEX telescope equipped with the SEPIA receiver. The 13CO J=6-5 line was placed in the same receiver sideband for simultaneous observation with the 658 GHz line of water. We have compared the 658 GHz line properties with our H2O radiative transfer models in stars and we have compared the velocity ranges of the 658 GHz and SiO J=2-1, v=1 maser lines. All stars show 658 GHz emission with a peak flux density in the range 50-70 Jy to 2000-3000 Jy. We have shown that the 658 GHz line is masing and we found that the 658 GHz velocity extent tends to be correlated with that of the SiO maser suggesting that both emission lines are excited in circumstellar layers close to the central star. Broad and stable line profiles are observed at 658 GHz. This could indicate maser saturation although we have tentatively provided first information on time variability at 658 GHz., 9 pages, 5 figures. Accepted in A&A

Published
2017

7. SEPIA – a new single pixel receiver at the APEX telescope (Corrigendum)

Author

Mathias Fredrixon, John Conway, Denis Meledin, E. De Beck, Michael Olberg, Sascha Krause, Hawal Rashid, Alexey Pavolotsky, K. Immer, C. De Breuck, S. Shafiee, Erik Sundin, J. Adema, Bhushan Billade, Andrey M. Baryshev, A. Koops, Per Bergman, W. Boland, J. Barkhof, Parisa Yadranjee Aghdam, J. P. Pérez-Beaupuits, Victor Belitsky, Andrey B. Ermakov, Ronald Hesper, M. E. Bekema, Sven-Erik Ferm, T. Klein, Magnus Strandberg, F. M. Montenegro-Montes, Hans Olofsson, Igor Lapkin, Pavel A. Yagoubov, K. Torstensson, and Vincent Desmaris

Subjects
Physics, Telescope, Optics, Space and Planetary Science, business.industry, law, Astronomy and Astrophysics, Astrophysics, Sepia, business, Apex (geometry), Single pixel, law.invention
Published
2018

8. Ortho-to-para ratio of NH2. Herschel-HIFI observations of ortho- and para-NH2 rotational transitions towards W31C, W49N, W51 and G34.3+0.1

Author

P. Hily-Blant, A. O. H. Olofsson, Friedrich Wyrowski, Alexandre Faure, E. Herbst, George E. Hassel, Maryvonne Gerin, Carina M. Persson, D. C. Lis, R. Le Gal, Michael Olberg, John H. Black, and Eva Wirström

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrochemistry, FOS: Physical sciences, Astrophysics, 010402 general chemistry, 01 natural sciences, 7. Clean energy, Protein filament, chemistry.chemical_compound, 0103 physical sciences, Radiative transfer, 010303 astronomy & astrophysics, Physics, Amidogen, Order (ring theory), Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, 0104 chemical sciences, chemistry, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Excited state, Atomic physics, Ground state, Excitation, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We have used the Herschel-HIFI instrument to observe both nuclear spin symmetries of amidogen (NH2) towards the high-mass star-forming regions W31C (G10.6-0.4), W49N (G43.2-0.1), W51 (G49.5-0.4) and G34.3+0.1. The aim is to investigate the ratio of nuclear spin types, the ortho-to-para ratio (OPR), of NH2. The excited NH2 transitions are used to construct radiative transfer models of the hot cores and surrounding envelopes in order to investigate the excitation and possible emission of the ground state rotational transitions of ortho-NH2 N_(K_a,K_c} J=1_(1,1) 3/2 - 0_(0,0) 1/2 and para-NH2 2_(1,2) 5/2 - 1_(0,1) 3/2$ used in the OPR calculations. Our best estimate of the average OPR in the envelopes lie above the high temperature limit of three for W49N, specifically 3.5 with formal errors of \pm0.1, but for W31C, W51, and G34.3+0.1 we find lower values of 2.5\pm0.1, 2.7\pm0.1, and 2.3\pm0.1, respectively. Such low values are strictly forbidden in thermodynamical equilibrium since the OPR is expected to increase above three at low temperatures. In the translucent interstellar gas towards W31C, where the excitation effects are low, we find similar values between 2.2\pm0.2 and 2.9\pm0.2. In contrast, we find an OPR of 3.4\pm0.1 in the dense and cold filament connected to W51, and also two lower limits of >4.2 and >5.0 in two other translucent gas components towards W31C and W49N. At low temperatures (T \lesssim 50 K) the OPR of H2 is 20-25 K, depending on time, and values above three at lower temperatures., 21 pages, 23 figures. Accepted by Astronomy and Astrophysics 30 Nov 2015

Published
2015

9. Periodic variation in the water production of comet C/2001 Q4 (NEAT) observed with the Odin satellite

Author

Dominique Bockelée-Morvan, Nicolas Biver, Urban Frisk, Michael Olberg, Åke Hjalmarson, Jacques Crovisier, Pierre Colom, Alain Lecacheux, Aa. Sandqvist, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Swedish Space Corporation (SSC), Onsala Space Observatory, Chalmers University of Technology (OSO), and Stockholm Observatory, AlbaNova University Center

Subjects
Physics, Astrochemistry, Comet, Astronomy and Astrophysics, Context (language use), Astrophysics, law.invention, Telescope, Outgassing, Amplitude, [SDU]Sciences of the Universe [physics], Space and Planetary Science, law, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Variation (astronomy), Line (formation)
Abstract

International audience; Context: Comet C/2001 Q4 (NEAT) was extensively studied with the 1.1-m submillimetre telescope of the Odin satellite. The H2O line at 557 GHz was regularly observed from 6 March to 16 May 2004 and nearly continuously monitored during 3 periods between 26 April and 2 May 2004. Aims: This last set of data shows periodic variations in the line intensity, and we looked for characterising the long- and short-term behaviour of this comet. Methods: We used the variance ratio method and chi2 minimization to find the period of variation in the water production rate and simulations to infer its amplitude at the nucleus surface. Results: A 40% periodic variation in the water production rate is measured with a period of 0.816±0.004 day (19.58±0.1 h). The comet also exhibits a seasonal effect with a mean peak of outgassing around 2.7×1029 molec. s-1 taking place about 18 days before perihelion.

Published
2009

10. Water and ammonia abundances in S140 with the Odin satellite

Author

A. O. H. Olofsson, Aa. Sandqvist, Carina M. Persson, Marco Spaans, T. Liljestrom, Åke Hjalmarson, D. R. Poelman, John H. Black, Urban Frisk, Michael Olberg, and Astronomy

Subjects
WAVE-ASTRONOMY-SATELLITE, 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Astrophysics, PHOTON-DOMINATED REGION, GAS-PHASE H2O, 1ST DETECTION, MASSIVE PROTOSTARS, MOLECULAR CLOUD, 01 natural sciences, ISM: abundances, Ammonia, chemistry.chemical_compound, Abundance (ecology), 0103 physical sciences, submillimeter, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Line (formation), Physics, STAR-FORMING REGIONS, SPECTRAL-LINE SURVEY, Astronomy and Astrophysics, line: profiles, Line width, ISM: molecules, ORION-KL, BANDS 486-492, chemistry, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Homogeneous, ISM: individual objects: S140, Outflow, Satellite, line: formation, Intensity (heat transfer)
Abstract

We have used the Odin satellite to obtain strip maps of the ground-state rotational transitions of ortho-water and ortho-ammonia, as well as CO(5-4) and 13CO(5-4) across the PDR, and H218O in the central position. A physi-chemical inhomogeneous PDR model was used to compute the temperature and abundance distributions for water, ammonia and CO. A multi-zone escape probability method then calculated the level populations and intensity distributions. These results are compared to a homogeneous model computed with an enhanced version of the RADEX code. H2O, NH3 and 13CO show emission from an extended PDR with a narrow line width of ~3 kms. Like CO, the water line profile is dominated by outflow emission, however, mainly in the red wing. The PDR model suggests that the water emission mainly arises from the surfaces of optically thick, high density clumps with n(H2)>10^6 cm^-3 and a clump water abundance, with respect to H2, of 5x10^-8. The mean water abundance in the PDR is 5x10^-9, and between ~2x10^-8 -- 2x10^-7 in the outflow derived from a simple two-level approximation. Ammonia is also observed in the extended clumpy PDR, likely from the same high density and warm clumps as water. The average ammonia abundance is about the same as for water: 4x10^-9 and 8x10^-9 given by the PDR model and RADEX, respectively. The similarity of water and ammonia PDR emission is also seen in the almost identical line profiles observed close to the bright rim. Around the central position, ammonia also shows some outflow emission although weaker than water in the red wing. Predictions of the H2O(110-101) and (111-000) antenna temperatures across the PDR are estimated with our PDR model for the forthcoming observations with the Herschel Space Observatory., 13 pages, 14 figures, 10 tables. Accepted for publication in Astronomy & Astrophysics 14 November 2008

Published
2009

11. A Swedish heterodyne facility instrument for the APEX telescope

Author

Doug Henke, Igor Lapkin, Olle Nyström, Magnus Strandberg, Mathias Fredrixon, Erik Sundin, Victor Belitsky, Per Bergman, Denis Meledin, Vessen Vassilev, Raquel Monje, Alexey Pavolotsky, Sven-Erik Ferm, Vincent Desmaris, Hans Olofsson, Miroslav Pantaleev, Michael Olberg, Dimitar Milkov Dochev, and Christophe Risacher

Subjects
Cryostat, Physics, Heterodyne, Noise temperature, Sideband, Physics::Instrumentation and Detectors, business.industry, Instrumentation, Bolometer, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, law.invention, Telescope, Optics, Space and Planetary Science, law, Physics::Accelerator Physics, Compatible sideband transmission, business, Astrophysics::Galaxy Astrophysics
Abstract

Aims. In March 2008, the APEX facility instrument was installed on the telescope at the site of Lliano Chajnantor in northern Chile. The main objective of the paper is to introduce the new instrument to the radio astronomical community. It describes the hardware configuration and presents some initial results from the on-sky commissioning. Methods. The heterodyne instrument covers frequencies between 211 GHz and 1390 GHz divided into four bands. The first three bands are sideband-separating mixers operating in a single sideband mode and based on superconductor-insulator-superconductor (SIS) tunnel junctions. The fourth band is a hot-electron bolometer, waveguide balanced mixer. All bands are integrated in a closedcycle temperature-stabilized cryostat and are cooled to 4 K. Results. We present results from noise temperature, sideband separation ratios, beam, and stability measurements performed on the telescope as a part of the receiver technical commissioning. Examples of broad extragalactic lines are also included.

Published
2008

12. Detection of CS emission towards Cygnus OB2 No. 12

Author

S. Casu, Michael Olberg, Flavio Scappini, and Cesare Cecchi-Pestellini

Subjects
Physics, Bok globule, Autocorrelator, Resolution (electron density), Astronomy, Astronomy and Astrophysics, Astrophysics, law.invention, Telescope, symbols.namesake, Space and Planetary Science, law, Brightness temperature, symbols, Cygnus OB2, Excitation, Line (formation)
Abstract

Aims.The CS (J = 2-1) line was searched at locations with brightest 13CO (J=1-0) emissions in the region in front of the star Cyg OB2 No. 12. Methods.The observations were made with the 20-m millimeter wave telescope at Onsala using a 1024-channel autocorrelator with a resolution of 50 kHz (0.14 km s-1). Results.The line was detected only in one position (core B) with main beam brightness temperature $T_{\rm MB} = 0.15(2)$ K at $v_{\rm LSR} = 11.4(1)$ km s-1. Conclusions.The line excitation analysis suggests that core B could be a Bok globule in consideration of its morphology, chemistry and physical conditions.

Published
2007

13. The structure of the cometary globule CG 12: a high-latitude star-forming region

Author

Michael Olberg and Lauri K. Haikala

Subjects
Physics, Line-of-sight, 010308 nuclear & particles physics, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Excitation temperature, Spatial distribution, 01 natural sciences, Latitude, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Molecule, Outflow, Maxima, 010303 astronomy & astrophysics, Excitation
Abstract

The structure of the high galactic latitude Cometary Globule 12 (CG 12) has been investigated by means of radio molecular line observations. Detailed, high signal to noise ratio maps in C18O (1-0), C18O (2-1) and molecules tracing high density gas, CS (3-2), DCO+ (2-1) and H13CO+ (1-0), are presented. The C18O line emission is distributed in a 10' long North-South elongated lane with two strong maxima, CG12 N(orth) and CG12 S(outh). In CG12 S the high density tracers delineate a compact core, DCO+ core, which is offset by 15" from the C18O maximum. The observed strong C18O emission traces the surface of the DCO+ core or a separate, adjacent cloud component. The emission in high density tracers is weak in CG12 N and especially the H13CO+, DCO+ and N2H+ lines are +0.5 km/s offset in velocity with respect to the C18O lines. Evidence is presented that the molecular gas is highly depleted. The observed strong C18O emission towards CG12 N originates in the envelope of this depleted cloud component or in a separate entity seen in the same line of sight. The C18O lines in CG 12 were analyzed using Positive Matrix Factorization, PMF. The shape and the spatial distribution of the individual PMF factors fitted separately to the C18O (1-0) and (2-1) transitions were consistent with each other. The results indicate a complex velocity and line excitation structure in the cloud. Besides separate cloud velocity components the C18O line shapes and intensities are influenced by excitation temperature variations caused by e.g, the molecular outflow or by molecular depletion. Assuming a distance of 630 pc the size of the CG 12 compact head, 1.1 pc by 1.8 pc, and the C18O mass larger than 100 Msun are comparable to those of other nearby low/intermediate mass star formation regions., Comment: 18 pages, 17 figures Accepted A&A Sep. 22 2006

Published
2007

14. On the progress in Odin’s hunt for molecules

Author

Henrik Olofsson, Åke Hjalmarson, S. Lundin, Urban Frisk, Carina M. Persson, Michael Olberg, Glenn Persson, Aage Sandqvist, and H. G. Floren

Subjects
Physics, Atmospheric Science, Spiral galaxy, Comet, Aerospace Engineering, Astronomy, Astronomy and Astrophysics, Astrophysics, Circumstellar envelope, Galaxy, Geophysics, Space and Planetary Science, Dark Ages, General Earth and Planetary Sciences
Abstract

Glimpses of new results from Odin’s fourth to sixth years of operation are presented: the first detection of interstellar O 2 ; the high water abundance in the M 42/Orion KL interface region; new results from the Orion KL spectral scan, including considerably improved knowledge of source physics and chemistry; the constant H 2 O/HCO + abundance ratio observed in diffuse, spiral arm clouds; mapping of shock-enhanced water emission in some nearby bipolar outflows; meaningful upper limits to the water abundance in nearby starburst galaxies; new mapping of the water emissions and absorptions in the Galactic Centre region – Sgr A; abundant self-absorbing water observed in the circumstellar envelope of R Doradus; very successful observations of many comets – including Tempel 1 (the target of Deep Impact) and recent observations of an outburst in the disintegrating Comet 73P/Schwassmann–Wachmann 3; and finally a note on our Odin searches for primordial molecules – potential structure probes during the dark ages of the evolution of the Universe.

Published
2007

15. On the accretion process in a high-mass star forming region - A multitransitional THz Herschel-HIFI study of ammonia toward G34.26+0.15

Author

John H. Black, Audrey Coutens, Carina M. Persson, Karl M. Menten, Michael Olberg, M. Hajigholi, Per Bergman, Åke Hjalmarson, Eva Wirström, A. O. H. Olofsson, and Friedrich Wyrowski

Subjects
Physics, 010308 nuclear & particles physics, Terahertz radiation, Star formation, Inverse, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Lambda, Astrophysics - Astrophysics of Galaxies, 01 natural sciences, Astrophysics - Solar and Stellar Astrophysics, Radiation pressure, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Radiative transfer, Outflow, 010303 astronomy & astrophysics, Excitation, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

[Abridged] Our aim is to explore the gas dynamics and the accretion process in the early phase of high-mass star formation. The inward motion of molecular gas in the massive star forming region G34.26+0.15 is investigated by using high-resolution profiles of seven transitions of ammonia at THz frequencies observed with Herschel-HIFI. The shapes and intensities of these lines are interpreted in terms of radiative transfer models of a spherical, collapsing molecular envelope. An accelerated Lambda Iteration (ALI) method is used to compute the models. The seven ammonia lines show mixed absorption and emission with inverse P-Cygni-type profiles that suggest infall onto the central source. A trend toward absorption at increasingly higher velocities for higher excitation transitions is clearly seen in the line profiles. The $J = 3\leftarrow2$ lines show only very weak emission, so these absorption profiles can be used directly to analyze the inward motion of the gas. This is the first time a multitransitional study of spectrally resolved rotational ammonia lines has been used for this purpose. Broad emission is, in addition, mixed with the absorption in the $1_0-0_0$ ortho-NH$_3$ line, possibly tracing a molecular outflow from the star forming region. The best-fitting ALI model reproduces the continuum fluxes and line profiles, but slightly underpredicts the emission and absorption depth in the ground-state ortho line $1_0-0_0$. The derived ortho-to-para ratio is approximately 0.5 throughout the infalling cloud core similar to recent findings for translucent clouds in sight lines toward W31C and W49N. We find evidence of two gas components moving inwards toward the central region with constant velocities: 2.7 and 5.3 km$\,$s$^{-1}$, relative to the source systemic velocity. The inferred mass accretion rates derived are sufficient to overcome the expected radiation pressure from G34.26+0.15., Comment: 20 pages, 18 figures, accepted by A&A 3 October 2015

Published
2015
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16. A 0.8 mm heterodyne facility receiver for the APEX telescope

Author

Lars-Göran Gunnarsson, Victor Belitsky, Magne Hagström, Mattias Svensson, L.-Å. Johansson, Hans Olofsson, Erik Sundin, Per Bergman, Christophe Risacher, Vessen Vassilev, Igor Lapkin, Roy Booth, Raquel Monje, Miroslav Pantaleev, L.-Å. Nyman, Michael Olberg, Alexey Pavolotsky, Sven-Erik Ferm, Mathias Fredrixon, and Denis Meledin

Subjects
Heterodyne, Physics, Noise temperature, Sideband, business.industry, Quantum noise, Astronomy and Astrophysics, law.invention, Telescope, Wavelength, Optics, Space and Planetary Science, law, Spectral resolution, business, Noise (radio)
Abstract

Aims. The new APEX telescope, located on Llano Chajnantor in Northern Chile, will have high resolution spectroscopic instruments covering the wavelength region from 0.20 to 1.30 mm (210-1500 GHz). Methods. In May 2005, the first facility receiver for the band 0.79-1.07 mm (279-381 GHz) was installed together with backends providing down to 60 kHz spectral resolution. This instrument that operates in double sideband mode uses superconducting tunnel junctions (SIS) as mixing elements operating at 4 K to achieve close to quantum-limited noise performances. The receiver is cooled by a closed-cycle cooling machine that allows continuous operation. The receiver design minimizes moving parts and is fully operated by remote to improve its reliability and the ease of use. Results. The double sideband (DSB) receiver temperatures are in the range 50-70 K, which typically results in a DSB system noise temperature of about 100 K in excellent weather conditions and between 100-200 K in good weather conditions.

Published
2006

17. Odin CO and $\mathsf{^{13}}$CO J = 5–4 mapping of Orion KL – a step towards accurate water abundances

Author

Eva Wirström, Michael Olberg, A. O. H. Olofsson, Per Bergman, Aa. Sandqvist, Carina M. Persson, Åke Hjalmarson, and Urban Frisk

Subjects
Physics, Brightness, Molecular cloud, Astronomy and Astrophysics, Astrophysics, law.invention, Telescope, Full width at half maximum, Space and Planetary Science, law, Brightness temperature, Radiative transfer, Emission spectrum, Line (formation)
Abstract

Aims. The very high main beam efficiency (90%) of the telescope on the sub-millimetre wave satellite Odin, in combination with the small calibration errors in the absence of atmospheric attenuation, assures that observed line brightness temperatures are very accurately determined. Based on this, we attempt to determine the column density distribution of H-2, and the ortho-water abundance, in the Orion KL region. Methods. We have, for the first time, mapped the (CO)-C-12 J = 5-4 emission in a 7' x 7' region covering Orion KL, observed simultaneously with a (CO)-C-13 J = 5-4 map. Also presented are (CO)-O-18 J = 5-4 emission data at four different positions and a (CO)-O-17 J = 5-4 emission spectrum detected towards the Orion KL position. The Odin mapping was performed at 1' spacing ( beam full width at half maximum 126'' at 557 GHz). Results. The CO J = 5-4 narrow line emission from this region mainly arises in the warm, dense gas at the interface ( the photon-dominated region) between the M42 HII region and the Orion A molecular cloud, the Orion PDR. The (CO)-C-12 and (CO)-C-13 J = 5-4 emission maps have been used to determine the column density distribution of H-2 gas across the Orion KL region. The results have been verified by comparing to column densities obtained using the decidedly optically thin (CO)-O-18 emission as input to the RADEX radiative transfer code. We find H-2 column densities ranging from 5 x 10(21) cm(-2) at map edges to 7 x 10(22) cm(-2) at the molecular ridge. The mass of the gas in the mapped region is estimated to be 480 M-circle dot, of which 320 M-circle dot is situated towards the molecular ridge. We estimate that about half of this mass belongs to the warm Orion PDR interface layer. Finally, based on data from the positions where (CO)-O-18 J = 5-4 has been observed, we estimate the ortho-water abundance in the Orion PDR layer to be >= 8 x 10(-8), higher than previously estimated.

Published
2006

18. Observations of the Circumstellar Water \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $1_{10}arrow 1_{01}$ \end{document} and Ammonia \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $1_{0}arrow 0_{0}$ \end{document} Lines in IRC +10216 by theOdinSatellite

Author

Sun Kwok, Urban Frisk, Åke Hjalmarson, Kay Justtanont, Fredrik L. Schöier, Hans Olofsson, Anders Winnberg, Kevin Volk, Aa. Sandqvist, L.-Å. Nyman, Tatsuhiko I. Hasegawa, N. Koning, and Michael Olberg

Subjects
Physics, Molecular line, Chemical models, Infrared, Astronomy, Rotational transition, Astronomy and Astrophysics, Astrophysics, Carbon star, Ammonia, chemistry.chemical_compound, chemistry, Space and Planetary Science, Asymptotic giant branch, Transfer model
Abstract

Submillimeter lines of H2O and NH3 have been detected in the carbon star IRC +10216 (CW Leo) with the Odin submillimeter satellite. The detection of the J = 110 → 101 557 GHz line of ortho-H2O confirms the earlier detection in the same source with SWAS. The detection of the JK = 10 → 00 572 GHz line represents the first observation of the ground-state rotational transition of NH3 in a stellar envelope. By fitting a molecular line transfer model to the observed lines, we derive an ortho-H2O abundance of 2.4 × 10-6, which is consistent with estimates from the SWAS observation. The derived ortho-NH3 abundance of 1 × 10-6 relative to H2 is significantly higher than those derived from 24 GHz inversion transitions and is slightly higher than those from vibrational transitions in the infrared band. The high H2O and NH3 abundances in the carbon-rich star IRC +10216 underscore shortcomings in the conventional gas-phase LTE and non-LTE chemical models.

Published
2006

19. W Hya through the eye of Odin

Author

Moshe Elitzur, Michael Olberg, Sun Kwok, Per Bergman, Tetsuo Hasegawa, Kevin Volk, Kay Justtanont, Hans Olofsson, Bengt Larsson, Aa. Sandqvist, Urban Frisk, Åke Hjalmarson, and Fredrik L. Schöier

Subjects
Physics, COSMIC cancer database, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Earth mass, Space and Planetary Science, Excess water, Radiative transfer, Asymptotic giant branch, Outflow, Satellite, Line (formation)
Abstract

We present Odin observations of the AGB star W Hya in the ground-state transition of ortho-H2O, 1(10)-1(01), at 557GHz. The line is clearly of circumstellar origin. Radiative transfer modelling of the water lines observed by Odin and ISO results in a mass-loss rate of (2.5 +/- 0.5)E-7 Msol/yr, and a circumstellar H2O abundance of (2.0 +/- 1.0)E-3. The inferred mass-loss rate is consistent with that obtained from modelling the circumstellar CO radio line emission, and also with that obtained from the dust emission modelling combined with a dynamical model for the outflow. The very high water abundance, higher than the cosmic oxygen abundance, can be explained by invoking an injection of excess water from evaporating icy bodies in the system. The required extra mass of water is quite small, on the order of ~ 0.1 earth mass., Comment: 7 pages, 6 figures Accepted for publication in Astronomy and Astrophysics

Published
2005

20. The diffuse clouds towards Cyg OB2 No. 5 and No. 12

Author

Cesare Cecchi-Pestellini, Michael Olberg, S. Casu, and Flavio Scappini

Subjects
Physics, Stars, Space and Planetary Science, Contour line, Astronomy and Astrophysics, Astrophysics, Line (formation)
Abstract

We have investigated, in the 13CO(1-0) line, the region between the stars Cyg OB2 No. 5 and No, 12. The integrated intensity contour map reveals the existence of a condensation at 12 km s-1 (core C), north-west of Cyg OB2 No. 5, with a core-halo structure. The morphology and the derived physical parameters make it quite similar to core A, previously discovered towards Cyg OB2 No. 12. A second condensation at 7 km s -1, near Cyg OB2 No. 12, has been mapped in the same line (1-0) of 13CO. A summary of different observations, in all spectral regions, towards Cyg OB2 No. 5 and No. 12 is presented to provide the material for a further comprehensive discussion of this intricate and still intriguing region.

Published
2005

21. Comparisons of MIPAS/ENVISAT ozone profiles with SMR/ODIN and HALOE/UARS observations

Author

T. von Clarmann, C. Jimenez, D. Y. Wang, E. Dupuy, Norbert Glatthor, Herbert Fischer, J. de La Noë, Udo Grabowski, Michael Olberg, Ashley Jones, Donal P. Murtagh, Philippe Ricaud, S. Wohnsiedler, James M. Russell, Gabriele Stiller, Joachim Urban, Ellis E. Remsberg, Martin Kaufmann, M.L. Koukouli, G. Mengistu Tsidu, Urban Frisk, Andrea Linden, Sylvia Kellmann, Manuel López-Puertas, Sergio Gil-Lopez, Patrick Eriksson, T. Steck, N. Lautie, Michael Höpfner, Bernd Funke, E. Le Flochmoën, Mathias Milz, and Michael Kiefer

Subjects
Atmospheric sounding, Atmospheric Science, Radiometer, Ozone, Equator, Aerospace Engineering, Astronomy and Astrophysics, Atmospheric sciences, Occultation, chemistry.chemical_compound, Geophysics, chemistry, Space and Planetary Science, Volume mixing ratio, General Earth and Planetary Sciences, Environmental science, Positive bias
Abstract

Ozone volume mixing ratio (VMR) profiles are measured by the Michelson Interferometer for passive atmospheric sounding (MIPAS) on ENVISAT. The data sets produced by the science data processor at Institut fur Meteorologic und Klimaforschung (IMK), Germany are compared with those obtained by halogen occultation experiment (HALOE) on UARS and by sub-millimetre radiometer (SMR) on ODIN. For the stratospheric measurements taken during September/October 2002, the three instruments show reasonable agreement, with global mean differences within 0.1-0.3 ppmv. The typical zonal mean differences are of 0.4 ppmv for HALOE and 0.6 ppmv for SMR (4-6%) in the ozone VMR peak region at 25-30 km near the equator, though larger differences of 0.8-1 ppmv (8-10%) are also observed in a small latitude-altitude region in the tropic. A positive bias of about 0.2-0.4 ppmv in the MIPAS data in the 35-40 km region has also been found. Further studies are under way to explain these differences.

Published
2005

22. The Odin satellite - II. Radiometer data processing and calibration

Author

Åke Hjalmarson, Alain Lecacheux, Steve Torchinsky, Urban Frisk, A. O. H. Olofsson, G. Florin, Michael Olberg, Philippe Baron, David Teyssier, Bengt Larsson, Kevin Volk, Aa. Sandqvist, Donal P. Murtagh, Laurent Pagani, Per Bergman, G. Olofsson, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Ingénieurs, Techniciens et Administratifs, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Physique des plasmas, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), and Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Data processing, Radiometer, Astronomy and Astrophysics, telescopes, techniques : spectroscopic, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Calibration, Satellite, submillimeter, Fixed frequency, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], space vehicles : instruments, Remote sensing
Abstract

The radiometer on-board the Odin satellite comprises four different sub-mm receivers covering the 486 - 581 GHz frequency range and one fixed frequency 119 GHz receiver. Two auto-correlators and one acousto-optical spectrometer serve as backends. This article gives an overview over the processing of the data delivered by these instruments and discusses calibration issues.

Published
2003

23. Observations of water in comets with Odin

Author

Aa. Sandqvist, G. Serra, Nicolas Biver, Pierre Encrenaz, Philippe Baron, Steve Torchinsky, Kalevi Mattila, Sun Kwok, A. O. H. Olofsson, Michael Olberg, Kevin Volk, Jacques Crovisier, Alain Lecacheux, Roy Booth, Hans Rickman, H. G. Floren, Dominique Bockelée-Morvan, Urban Frisk, L. Nordh, F. von Schéele, Anders Winnberg, Åke Hjalmarson, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Ingénieurs, Techniciens et Administratifs, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Physique des plasmas, Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)

Subjects
Physics, 010308 nuclear & particles physics, Comet, Astronomy, Astronomy and Astrophysics, Coma (optics), Astrophysics, 01 natural sciences, Outgassing, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, 0103 physical sciences, Satellite, Spectral resolution, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Anisotropy, 010303 astronomy & astrophysics, Optical depth, Line (formation)
Abstract

The Odin satellite, which can observe the 1 1 0 -1 0 1 rotational line at 557 GHz of ortho water with a high spectral resolution (80 m s - 1 ) and a spatial resolution of 2.1', is well suited for cometary studies. The intensity of this line provides an estimate of the water production rate. The line width gives a direct measure of the coma expansion velocity. The line centre position and shape are affected by the anisotropy of the outgassing and by optical depth effects. Comets observed with Odin up to now are C/2001 A2 (LINEAR) during the commissioning phase of the satellite, 19P/Borrelly at the time of the Deep Space 1 flyby, C/2000 WM 1 (LINEAR), and 153P/2002 Cl (Ikeya-Zhang). For this last comet, thorough observations were made at the moment of its closest approach to Earth at the end of April 2002. A deep integration resulted in the detection of the 1 1 0 -1 0 1 line of H 2 1 8 O at 548 GHz. No 1 6 O/ 1 8 O isotopic anomaly is found.

Published
2003

24. Low upper limits on the O2abundance from the Odin satellite

Author

George F. Mitchell, Nicholas F. H Tothill, G. Serra, Roy Booth, Kalevi Mattila, T. Liljeström, Bengt Larsson, P. A. Feldman, Christine D. Wilson, Per Bergman, Pierre Encrenaz, Michael Lindqvist, F. von Schéele, John H. Black, Maryvonne Gerin, Edith Falgarone, L. Nordh, G. Olofsson, E. M. Gregersen, René Liseau, L. E. B. Johansson, Michael Olberg, I. Ristorcelli, Sun Kwok, Jacques Crovisier, Åke Hjalmarson, Urban Frisk, Kevin Volk, V. Buat, Alain Lecacheux, Aa. Sandqvist, H. G. Floren, Peter F. Bernath, Michel Fich, A. O. H. Olofsson, Tatsuhiko I. Hasegawa, Laurent Pagani, Tommy Wiklind, Jorma Harju, Charles L. Curry, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Physique des plasmas, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)

Subjects
Physics, 010308 nuclear & particles physics, Astronomy, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Galaxy, Space and Planetary Science, Abundance (ecology), 0103 physical sciences, Satellite, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Ground state, 010303 astronomy & astrophysics
Abstract

For the first time, a search has been conducted in our Galaxy for the 119 GHz transition connecting to the ground state of O2, using the Odin satellite. Equipped with a sensitive 3 mm receiver (Tsy ...

Published
2003

25. First detection of NH3 ($\mathsf{1_0 \rightarrow 0_0}$) from a low mass cloud core

Author

Laurent Pagani, Urban Frisk, Kevin Volk, T. Liljeström, G. Serra, George F. Mitchell, Sun Kwok, E. M. Gregersen, Pierre Encrenaz, E. Falgarone, Michael Olberg, I. Ristorcelli, Jorma Harju, Lars E B Johansson, Roy Booth, Nicholas F. H Tothill, P. A. Feldman, Maryvonne Gerin, Charles L. Curry, K. Mattila, René Liseau, Rene Plume, M. Fich, Peter F. Bernath, G. Olofsson, Alain Lecacheux, V. Buat, H. G. Floren, Fredrik von Schéele, John H. Black, L. Nordh, Åke Hjalmarson, Christine D. Wilson, Tetsuo Hasegawa, Per Bergman, Alexis Brandeker, Aa. Sandqvist, and Bengt Larsson

Subjects
Physics, Molecular line, Abundance (chemistry), Analytical chemistry, Astronomy and Astrophysics, Astrophysics, Core (optical fiber), Ammonia, chemistry.chemical_compound, chemistry, Space and Planetary Science, Ground state, Low Mass, Excitation, Line (formation)
Abstract

Odin has successfully observed the molecular core rho Oph A in the 572.5 GHz rotational ground state line of ammonia, NH3 (J,K = 1,0 - 0,0). The interpretation of this result makes use of complementary molecular line data obtained from the ground (C17O and CH3OH) as part of the Odin preparatory work. Comparison of these observations with theoretical model calculations of line excitation and transfer yields a quite ordinary abundance of methanol, X(CH3OH) = 3e-9. Unless NH3 is not entirely segregated from C17O and CH3OH, ammonia is found to be significantly underabundant with respect to typical dense core values, viz. X(NH3) = 8e-10.

Published
2003

26. The discovery of clumpy structure in the diffuse gas towards Cyg OB2 No. 12

Author

Michael Olberg, Flavio Scappini, Silvia Casu, and Cesare Cecchi-Pestellini

Subjects
Physics, Line-of-sight, media_common.quotation_subject, Structure (category theory), Astronomy, Astronomy and Astrophysics, Astrophysics, Star (graph theory), Space and Planetary Science, Sky, Low temperature combustion, Molecular materials, Line (formation), media_common
Abstract

We have mapped the 1 3 CO (1-0) line in a region of sky towards the star Cyg OB2 No. 12. The observations rule out the possibility that the molecular material along the line of sight is distributed over a long path of very dilute gas. Instead, we present unambiguous evidence of well-defined kinematical structures, which might be assembled to form a cloud complex. The chemistry that leads to H 3 + appears decoupled from that responsible for the production of heavier species.

Published
2002

27. Simultaneous 183 GHz H2O maser and SiO observations towards evolved stars using APEX SEPIA Band 5

Author

C. De Breuck, K. Immer, Sandra Etoka, K. Torstensson, E. De Beck, Malcolm Gray, Elizabeth Humphreys, Alain Baudry, Wouter Vlemmings, Anita M. S. Richards, Markus Wittkowski, Palle Møller, Michael Olberg, Pinelands Field Station, Rutgers University System (Rutgers), FORMATION STELLAIRE 2017, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Cardiff University, European Southern Observatory (ESO), Theoretical Division [LANL], Los Alamos National Laboratory (LANL), Department of Earth and Space Sciences [Göteborg], and Chalmers University of Technology [Göteborg]

Subjects
010504 meteorology & atmospheric sciences, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, law.invention, law, 0103 physical sciences, Radiative transfer, Astrophysics::Solar and Stellar Astrophysics, Asymptotic giant branch, Red supergiant, Maser, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Linear polarization, Astronomy and Astrophysics, Polarization (waves), Astrophysics - Astrophysics of Galaxies, Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Astrophysics::Earth and Planetary Astrophysics, Supergiant
Abstract

We investigate the use of 183 GHz H2O masers for characterization of the physical conditions and mass loss process in the circumstellar envelopes of evolved stars. We used APEX SEPIA Band 5 to observe the 183 GHz H2O line towards 2 Red Supergiant and 3 Asymptotic Giant Branch stars. Simultaneously, we observed lines in 28SiO v0, 1, 2 and 3, and for 29SiO v0 and 1. We detected the 183 GHz H2O line towards all the stars with peak flux densities greater than 100 Jy, including a new detection from VY CMa. Towards all 5 targets, the water line had indications of being due to maser emission and had higher peak flux densities than for the SiO lines. The SiO lines appear to originate from both thermal and maser processes. Comparison with simulations and models indicate that 183 GHz maser emission is likely to extend to greater radii in the circumstellar envelopes than SiO maser emission and to similar or greater radii than water masers at 22, 321 and 325 GHz. We speculate that a prominent blue-shifted feature in the W Hya 183 GHz spectrum is amplifying the stellar continuum, and is located at a similar distance from the star as mainline OH maser emission. From a comparison of the individual polarizations, we find that the SiO maser linear polarization fraction of several features exceeds the maximum fraction allowed under standard maser assumptions and requires strong anisotropic pumping of the maser transition and strongly saturated maser emission. The low polarization fraction of the H2O maser however, fits with the expectation for a non-saturated maser. 183 GHz H2O masers can provide strong probes of the mass loss process of evolved stars. Higher angular resolution observations of this line using ALMA Band 5 will enable detailed investigation of the emission location in circumstellar envelopes and can also provide information on magnetic field strength and structure., Comment: 11 pages, accepted by A&A. The abstract here has been shortened

Published
2017

28. Odinobservations of ammonia in the Sgr A +50 km s-1cloud and circumnuclear disk

Author

Michael Olberg, L. Nordh, Urban Frisk, Aa. Sandqvist, G. Olofsson, Åke Hjalmarson, and S. Lundin

Subjects
Physics, Spiral galaxy, Line-of-sight, 010308 nuclear & particles physics, Milky Way, Astronomy and Astrophysics, Context (language use), Astrophysics, 01 natural sciences, Galaxy, Space and Planetary Science, 0103 physical sciences, Satellite, 010303 astronomy & astrophysics, Line (formation)
Abstract

Context. The Odin satellite is now into its sixteenth year of operation, much surpassing its design life of two years. One of the sources which Odin has observed in great detail is the Sgr A Complex in the centre of the Milky Way. Aims. To study the presence of NH3 in the Galactic Centre and spiral arms. Methods. Recently, Odin has made complementary observations of the 572 GHz NH3 line towards the Sgr A +50 km/s Cloud and Circumnuclear Disk (CND). Results. Significant NH3 emission has been observed in both the +50 km/s Cloud and the CND. Clear NH3 absorption has also been detected in many of the spiral arm features along the line of sight from the Sun to the core of our Galaxy. Conclusions. The very large velocity width (80 km/s) of the NH3 emission associated with the shock region in the southwestern part of the CND may suggest a formation/desorption scenario similar to that of gas-phase H2O in shocks/outflows.

Published
2017

29. Upper limits to interstellar NH+ and para-NH2- abundances. Herschel-HIFI observations towards Sgr B2 (M) and G10.6-0.4 (W31C)

Author

E. Herbst, Michael Olberg, A. O. H. Olofsson, Eva Wirström, George E. Hassel, Herma M. Cuppen, John H. Black, Karl M. Menten, Åke Hjalmarson, M. Hajigholi, Carina M. Persson, D. C. Lis, Maryvonne Gerin, José Cernicharo, and Holger S. P. Müller

Subjects
Physics, FOS: Physical sciences, chemistry.chemical_element, Rotational transition, Astronomy and Astrophysics, Astrophysics, Nitrogen, Astrophysics - Astrophysics of Galaxies, Space observatory, Ion, chemistry, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Ionization, Theoretical Chemistry, Ground state, Hyperfine structure, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries)
Abstract

The understanding of interstellar nitrogen chemistry has improved significantly with recent results from the Herschel Space Observatory. To set even better constraints, we report here on deep searches for the NH+ ground state rotational transition J=1.5-0.5 of the ^2Pi_1/2 lower spin ladder, with fine-structure transitions at 1013 and 1019 GHz, and the para-NH2- 1_1,1-0_0,0 rotational transition at 934 GHz towards Sgr B2(M) and G10.6-0.4 using Herschel-HIFI. No clear detections of NH+ are made and the derived upper limits are, 14 pages, 19 figures, accepted for publication in Astronomy & Astrophysics 21 May, 2014

Published
2014

30. The effect of sideband ratio on line intensity for Herschel/HIFI

Author

R. Shipman, Frank Helmich, Michael Olberg, J. Braine, Volker Ossenkopf, John C. Pearson, Bertrand Delforge, David Teyssier, Ronan Higgins, Colin Borys, Claudia Comito, European Space Astronomy Centre (ESAC), European Space Agency (ESA), FORMATION STELLAIRE 2014, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), and Astronomy

Subjects
Heterodyne, Sideband ratio, [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], FOS: Physical sciences, Astrophysics, Optics, Far infrared, Herschel, Calibration, Instrumentation and Methods for Astrophysics (astro-ph.IM), Line (formation), Physics, Sideband, business.industry, Astronomy and Astrophysics, Intensity (physics), [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Space and Planetary Science, Orbit (dynamics), Instrumentation and Methods for Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, business, HIFI, Test data
Abstract

The Heterodyne Instrument for the Far Infrared (HIFI) on board the Herschel Space Observatory is composed of a set of fourteen double sideband mixers. We discuss the general problem of the sideband ratio (SBR) determination and the impact of an imbalanced sideband ratio on the line calibration in double sideband heterodyne receivers. The HIFI SBR is determined from a combination of data taken during pre-launch gas cell tests and in-flight. The results and some of the calibration artefacts discovered in the gas cell test data are presented here along with some examples of how these effects appear in science data taken in orbit., Comment: 21 pages, 10 figues. To be published in special Herschel calibration issue of Experimental Astronomy

Published
2014

31. Hydroxyl, water, ammonia, carbon monoxide and neutral carbon towards the Sgr A complex

Author

Urban Frisk, Aage Sandqvist, Roland Karlsson, Michael Olberg, Anders Winnberg, Kambiz Fathi, and Åke Hjalmarson

Subjects
Absorption spectroscopy, Star formation, chemistry.chemical_element, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics - Astrophysics of Galaxies, chemistry.chemical_compound, Ammonia, chemistry, Space and Planetary Science, Desorption, Astrophysics of Galaxies (astro-ph.GA), Absorption (chemistry), Carbon, Carbon monoxide, Line (formation)
Abstract

We observed OH, H$_2$O, HN$_3$, C$^{18}$O, and C$_I$ towards the +50 km/s cloud (M-0.02-0.07), the CND and the +20 km/s (M-0.13-0.08) cloud in the Sgr A complex with the VLA, Odin and SEST. Strong OH absorption, H$_2$O emission and absorption lines were seen at all three positions. Strong C$^{18}$O emissions were seen towards the +50 and +20 km/s clouds. The CND is rich in H$_2$O and OH, and these abundances are considerably higher than in the surrounding clouds, indicating that shocks, star formation and clump collisions prevail in those objects. A comparison with the literature reveals that it is likely that PDR chemistry including grain surface reactions, and perhaps also the influences of shocks has led to the observed abundances of the observed molecular species studied here. In the redward high-velocity line wings of both the +50 and +20 km/s clouds and the CND, the very high H$_2$O abundances are suggested to be caused by the combined action of shock desorption from icy grain mantles and high-temperature, gas-phase shock chemistry. Only three of the molecules are briefly discussed here. For OH and H$_2$O three of the nine observed positions are shown, while a map of the C$^{18}$O emission is provided. An extensive paper was recently published with Open Access (Karlsson et al. 2013; http://www.aanda.org/articles/aa/pdf/2013/06/aa20471-12.pdf )., Proc. of a Conf. on IAU Symposium No.303: The Galactic Center: Feeding and Feedback in a Normal Galactic Nucleus 2013, Santa Fe, NM (USA)

Published
2013

32. Millimeter‐Wave Observations of Molecular Lines toward Bok Globules and Herbig Ae/Be Stars

Author

C. Fanti, A. Casolari, F. Scappini, Cesare Cecchi-Pestellini, and Michael Olberg

Subjects
Physics, Molecular line, Infrared, Bok globule, Molecular cloud, Astronomy, Astronomy and Astrophysics, Astrophysics, Herbig Ae/Be star, Wavelength, symbols.namesake, Stars, Space and Planetary Science, Extremely high frequency, symbols, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

A sample of 14 small Bok globules and of eight Herbig Ae/Be stars has been observed in the molecular rotational lines of HCO+, HCN, HNC, N2H+, and C2H at 3 mm wavelength. The observational results have been used together with a pseudo-time-dependent chemical model to study the evolution of a molecular cloud toward the formation of a low-mass star. The new chemical and physical scenario that is inferred from the molecular line data is discussed in relation with the existing literature data obtained from infrared to far-infrared data.

Published
1998

33. Herschel celestial calibration sources: Four large main-belt asteroids as prime flux calibrators for the far-IR/sub-mm range

Author

T. L. Lim, C. Pearson, G. Bendo, Michael Olberg, M. Nielbock, Esa Vilenius, Zoltan Balog, Bruno Altieri, Hendrik Linz, Ulrich Klaas, T. Mueller, and D. Teyssier

Subjects
Physics, Earth and Planetary Astrophysics (astro-ph.EP), Uranus, Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Mars Exploration Program, Albedo, Stars, Space and Planetary Science, Neptune, Asteroid, Planet, Calibration, Astrophysics - Earth and Planetary Astrophysics
Abstract

Celestial standards play a major role in observational astrophysics. They are needed to characterise the performance of instruments and are paramount for photometric calibration. During the Herschel Calibration Asteroid Preparatory Programme approximately 50 asteroids have been established as far-IR/sub-mm/mm calibrators for Herschel. The selected asteroids fill the flux gap between the sub-mm/mm calibrators Mars, Uranus and Neptune, and the mid-IR bright calibration stars. All three Herschel instruments observed asteroids for various calibration purposes, including pointing tests, absolute flux calibration, relative spectral response function, observing mode validation, and cross-calibration aspects. Here we present newly established models for the four large and well characterized main-belt asteroids (1) Ceres, (2) Pallas, (4) Vesta, and (21) Lutetia which can be considered as new prime flux calibrators. The relevant object-specific properties (size, shape, spin-properties, albedo, thermal properties) are well established. The seasonal (distance to Sun, distance to observer, phase angle, aspect angle) and daily variations (rotation) are included in a new thermophysical model setup for these targets. The thermophysical model predictions agree within 5% with the available (and independently calibrated) Herschel measurements. The four objects cover the flux regime from just below 1,000 Jy (Ceres at mid-IR N-/Q-band) down to fluxes below 0.1 Jy (Lutetia at the longest wavelengths). Based on the comparison with PACS, SPIRE and HIFI measurements and pre-Herschel experience, the validity of these new prime calibrators ranges from mid-infrared to about 700 micron, connecting nicely the absolute stellar reference system in the mid-IR with the planet-based calibration at sub-mm/mm wavelengths., Comment: Published in Experimental Astronomy, 78 pages, 10 figures, 19 tables

Published
2013
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34. Detection of 183 GHz H2O megamaser emission towards NGC 4945

Author

C. De Breuck, Wouter Vlemmings, Victor Belitsky, Maud Galametz, Michael Olberg, Caterina M. V. Impellizzeri, John Conway, and Elizabeth Humphreys

Subjects
Physics, Supermassive black hole, Active galactic nucleus, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Megamaser, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Galaxy, Redshift, law.invention, Luminosity, Stars, Space and Planetary Science, law, 0103 physical sciences, Maser, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

Aims. The aim of this work is to search Seyfert 2 galaxy NGC 4945, a well-known 22 GHz water megamaser galaxy, for H2O (mega) maser emission at 183 GHz. Methods. We used APEX SEPIA Band 5 (an ALMA Band 5 receiver on the APEX telescope) to perform the observations. Results. We detected 183 GHz H2O maser emission towards NGC 4945 with a peak flux density of similar to 3 Jy near the galactic systemic velocity. The emission spans a velocity range of several hundred km s(-1). We estimate an isotropic luminosity of > 1000 L-circle dot, classifying the emission as a megamaser. A comparison of the 183 GHz spectrum with that observed at 22 GHz suggests that 183 GHz emission also arises from the active galactic nucleus (AGN) central engine. If the 183 GHz emission originates from the circumnuclear disk, then we estimate that a redshifted feature at 1084 km s(-1) in the spectrum should arise from a distance of 0.022 pc from the supermassive black hole (1.6 x 10(5) Schwarzschild radii), i.e. closer than the water maser emission previously detected at 22 GHz. This is only the second time 183 GHz maser emission has been detected towards an AGN central engine (the other galaxy being NGC 3079). It is also the strongest extragalactic millimetre/submillimetre water maser detected to date. Conclusions. Strong millimetre 183 GHz H2O maser emission has now been shown to occur in an external galaxy. For NGC 4945, we believe that the maser emission arises, or is dominated by, emission from the AGN central engine. Emission at higher velocity, i.e. for a Keplerian disk closer to the black hole, has been detected at 183 GHz compared with that for the 22 GHz megamaser. This indicates that millimetre/submillimetre H2O masers can indeed be useful for tracing out more of AGN central engine structures and dynamics than previously probed. Future observations using ALMA Band 5 should unequivocally determine the origin of the emission in this and other galaxies.

Published
2016

35. In-orbit performance of Herschel-HIFI

Author

N. Whyborn, Per Bjerkeli, Pieter R. Roelfsema, Dominicus Kester, L. Dubbeldam, Q. Xie, Claudia Comito, Z. Nagy, A. Marston, R. Moreno, J. Rector, C. Gal, M. H. D. van der Wiel, M. Akyilmaz, Christian Leinz, Michael Olberg, Miriam Rengel, Mihkel Kama, T. Klein, D. R. Higgins, Tomasz S. Kaminski, Yoko Okada, E. Sánchez-Suárez, S. Pacheco, G. de Lange, J. Stutzki, I. M. Avruch, W. Salomons, R. Assendorp, Tom Bell, R. Shipman, W. Nowosielski, O. Coeur-Joly, Volker Ossenkopf, Adwin Boogert, C. Kramer, W. M. Laauwen, S. D. Lord, J. C. Pearson, M. Marseille, Rudolf Schieder, Piotr Orleanski, J. Braine, C. K. Wafelbakker, D. Rabois, C. McCoey, Marco Soldati, A. de Jonge, L. Ravera, Charlotte Vastel, Christopher Jarchow, S. Wang, F. Schlöder, F. Flederus, W. Luinge, Pieter Dieleman, Umut A. Yildiz, Robin Lombaert, Christophe Risacher, Emmanuel Caux, Nathan R. Crockett, B. Delforge, M. Melchior, M. De Luca, Willem Jellema, Fabrice Herpin, N. Biver, A. Lorenzani, Thomas G. Phillips, B. Thomas, Patrick W. Morris, K. Wildeman, E. De Beck, P. Zaal, Hideo Sagawa, Jesús Martín-Pintado, K. Edwards, R. Huisman, Colin Borys, M. Caris, Alexander G. G. M. Tielens, Michel Fich, Jacob Kooi, Th. de Graauw, M. Michalska, Z. Makai, M. Xilouris, A. Hoac, Frank Helmich, Thibault Cavalié, F. Schmülling, Bengt Larsson, D. A. Beintema, A. M. di Giorgio, José Cernicharo, Holger S. P. Müller, Bertrand Lefloch, D. Teyssier, Pierre Hily-Blant, SRON Netherlands Institute for Space Research (SRON), Infrared Processing and Analysis Center (IPAC), California Institute of Technology (CALTECH), Onsala Space Observatory, Chalmers University of Technology [Göteborg], foreign laboratories (FL), CERN [Genève], ESO, European Southern Observatory (ESO), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), FORMATION STELLAIRE 2012, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), CNRS INSU, UMR 5187, F-31028 Toulouse 4, France, UMR 5187 Toulouse, Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Max Planck Institute for Radio Astronomy, Max-Planck-Institut für Radioastronomie (MPIFR), Instituto de RadioAstronomía Milimétrica (IRAM), Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, I. Physikalisches Institut [Köln], Universität zu Köln = University of Cologne, SSE 2012, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Department of Astronomy [Ann Arbor], University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Laboratoire Univers et Théories (LUTH (UMR_8102)), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA, CALTECH, Ctr Infrared Proc & Anal, Pasadena, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Univ Toulouse UPS, Ctr Etud Spatiale Rayonnements, F-31062 Toulouse 9, France, Centre Etud Spatiale Rayonnements Toulouse, Ctr Astrobiol CSIC INTA, Lab Astrofis Mol, Madrid 28850, Spain, Ctr Astrobiol CSIC INTA, Lab Astrofis Mol, Madrid, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung (MPS), Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany, Univ Cologne, Inst Phys 1, Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), École normale supérieure - Paris (ENS Paris), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Universität zu Köln, Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Kapteyn Astronomical Institute, Astronomy, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Heterodyne, Physics, [PHYS]Physics [physics], 010504 meteorology & atmospheric sciences, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Instrumentation, Astrophysics::Instrumentation and Methods for Astrophysics, ASTRONOMY, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, 7. Clean energy, Methods observational, Space and Planetary Science, 0103 physical sciences, Orbit (dynamics), Calibration, methods: observational, space vehicles: instruments, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Remote sensing, instrumentation: spectrographs
Abstract

International audience; Aims: In this paper the calibration and in-orbit performance of the Heterodyne Instrument for the Far-Infrared (HIFI) is described. Methods: The calibration of HIFI is based on a combination of ground and in-flight tests. Dedicated ground tests to determine those instrument parameters that can only be measured accurately using controlled laboratory stimuli were carried out in the instrument level test (ILT) campaign. Special in-flight tests during the commissioning phase (CoP) and performance verification (PV) allowed the determination of the remaining instrument parameters. The various instrument observing modes, as specified in astronomical observation templates (AOTs), were validated in parallel during PV by observing selected celestial sources. Results: The initial calibration and in-orbit performance of HIFI has been established. A first estimate of the calibration budget is given. The overall in-flight instrument performance agrees with the original specification. Issues remain at only a few frequencies. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

Published
2012

36. Odin space telescope monitoring of water vapor in the stratosphere of Jupiter

Author

J. Brillet, N. Biver, E. Lellouch, Michael Olberg, Michel Dobrijevic, Urban Frisk, Thibault Cavalié, Alain Lecacheux, Åke Hjalmarson, F. Billebaud, Paul Hartogh, Aa. Sandqvist, SSE 2012, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Swedish Space Corporation (SSC), Onsala Space Observatory, Chalmers University of Technology [Göteborg], Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), and Max-Planck-Institut für Sonnensystemforschung (MPS)

Subjects
Physics, [PHYS]Physics [physics], 010504 meteorology & atmospheric sciences, Astronomy, Astronomy and Astrophysics, 01 natural sciences, Atmosphere, Jupiter, Interplanetary dust cloud, Spitzer Space Telescope, Rings of Jupiter, 13. Climate action, Space and Planetary Science, Planet, 0103 physical sciences, Satellite, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Stratosphere, 0105 earth and related environmental sciences
Abstract

International audience; The Odin space telescope has monitored the H2O (110-101) line in Jupiter's stratosphere over the 2003-2009 period. When comparing these data with previous spectra obtained with SWAS and Odin over the 1999-2002 period, we see no significant variations in the line-to-continuum ratio of the H2O line over the whole period. We have however tentatively identified a decrease by ∼15% of the line-to-continuum ratio between 2002 and 2007-2009, indicating that there was less H2O in the stratosphere of Jupiter in 2007-2009 than anticipated. We have tested the IDP (interplanetary dust particles) and SL9 (Shoemaker-Levy 9) 1D time-dependent models presented in Cavalié et al. [2008, Observation of water vapor in the stratosphere 613 of Jupiter with the Odin space telescope. Planetary and Space Science 56, 1573-1584]. We present a series of scenarios that lead to satisfactory fits of the whole data set (1999-2002 and 2003-2009 periods) based on IDP and SL9 models. The evolution of Jupiter's stratospheric H2O that we have tentatively observed has however to be confirmed by Herschel/HIFI observations. If the decrease of the line-to-continuum ratio is confirmed by future observations, it would be a direct evidence that Jupiter's H2O comes from SL9. In addition, this study shows that new constraints on Jupiter's eddy diffusion coefficient profile could be obtained (in the pressure ranges that are probed) from the monitoring of SL9 species in its stratosphere.

Published
2012

37. Herschel observations of the Herbig-Haro objects HH52-54

Author

Kay Justtanont, G. J. Herczeg, A. O. H. Olofsson, C. McCoey, René Liseau, Per Bergman, Mario Tafalla, Odysseas Dionatos, Brunella Nisini, M. Benedettini, Per Bjerkeli, Teresa Giannini, Bengt Larsson, and Michael Olberg

Subjects
Shock wave, Physics, formation [stars], jets and outflows [ISM], FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics - Astrophysics of Galaxies, Spectral line, Shock (mechanics), Herbig-Haro objects, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Radiative transfer, Outflow, Herbig–Haro object, Spectral resolution, winds, outflows [stars], molecules [ISM], Astrophysics::Galaxy Astrophysics, Line (formation)
Abstract

We are aiming at the observational estimation of the relative contribution to the cooling by CO and H2O, as this provides decisive information for the understanding of the oxygen chemistry behind interstellar shock waves. Methods. The high sensitivity of HIFI, in combination with its high spectral resolution capability, allows us to trace the H2O outflow wings at unprecedented signal-to-noise. From the observation of spectrally resolved H2O and CO lines in the HH52-54 system, both from space and from ground, we arrive at the spatial and velocity distribution of the molecular outflow gas. Solving the statistical equilibrium and non-LTE radiative transfer equations provides us with estimates of the physical parameters of this gas, including the cooling rate ratios of the species. The radiative transfer is based on an ALI code, where we use the fact that variable shock strengths, distributed along the front, are naturally implied by a curved surface. Based on observations of CO and H2O spectral lines, we conclude that the emission is confined to the HH54 region. The quantitative analysis of our observations favours a ratio of the CO-to-H2O-cooling-rate >> 1. From the best-fit model to the CO emission, we arrive at an H2O abundance close to 1e-5. The line profiles exhibit two components, one of which is triangular and another, which is a superposed, additional feature. This additional feature likely originates from a region smaller than the beam where the ortho-water abundance is smaller than in the quiescent gas. Comparison with recent shock models indicate that a planar shock can not easily explain the observed line strengths and triangular line profiles.We conclude that the geometry can play an important role. Although abundances support a scenario where J-type shocks are present, higher cooling rate ratios than predicted by these type of shocks are derived., Accepted for publication in A&A

Published
2011
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38. Herschel/HIFI detections of hydrides towards AFGL 2591. Envelope emission versus tenuous cloud absorption [Letter]

Author

Javier R. Goicoechea, M. Tafalla, Pierre Encrenaz, P. Stäuber, Jes K. Jørgensen, Jonathan Braine, T. Giannini, Laurent Pagani, Steven D. Doty, Alain Baudry, Michael Olberg, Rafael Bachiller, M. Marseille, Th. de Graauw, E. F. van Dishoeck, Lars E. Kristensen, R. Schieder, José Cernicharo, André Csillaghy, S. Bruderer, S. F. Wampfler, T. A. van Kempen, Paolo Saraceno, Arnold O. Benz, Gary J. Melnick, David A. Neufeld, T. Jacq, C. Dedes, J. Santiago-Garcia, N. Honingh, John C. Pearson, R. Shipman, Frank Helmich, D. Teyssier, M. Fich, A. Di Giorgio, Willem Jellema, Edwin Bergin, Per Bjerkeli, N. Whyborn, Paola Caselli, R. Plume, Ruud Visser, Dariusz C. Lis, M. Melchior, Fabrice Herpin, Christophe Risacher, B. Larsson, Emmanuel Caux, Brunella Nisini, C. McCoey, Christian Monstein, F. Daniel, Geoffrey A. Blake, Doug Johnstone, Gregory J. Herczeg, Umut A. Yildiz, Berengere Parise, Claudio Codella, Sylvain Bontemps, René Liseau, Milena Benedettini, Michiel R. Hogerheijde, Friedrich Wyrowski, Carsten Dominik, F. F. S. van der Tak, W. Bächtold, Asunción Fuente, Low Energy Astrophysics (API, FNWI), Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Herschel Science Center [Madrid], European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), SRON Netherlands Institute for Space Research (SRON), INAF - Osservatorio Astronomico di Roma (OAR), Onsala Space Observatory, Chalmers University of Technology [Göteborg], ESO, European Southern Observatory (ESO), Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Max-Planck-Institut für Radioastronomie (MPIFR), École normale supérieure - Paris (ENS Paris), European Space Agency (ESA)-European Space Agency (ESA), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, and Consiglio Nazionale delle Ricerche (CNR)

Subjects
Photon, FOS: Physical sciences, Astrophysics, 7. Clean energy, Far infrared, CHEMISTRY, EXCITATION, OUTFLOW, Solar and Stellar Astrophysics, Spectral resolution, H2O+, Absorption (electromagnetic radiation), Solar and Stellar Astrophysics (astro-ph.SR), Envelope (waves), QB, STAR-FORMING REGIONS, Physics, stars: formation, SPECTROSCOPY, INTERSTELLAR-MEDIUM, astrochemistry, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Diatomic molecule, ISM: molecules, Astrophysics - Solar and Stellar Astrophysics, GL-2591, 13. Climate action, Space and Planetary Science, ABUNDANCE, Outflow, ISM: individual objects: AFGL 2591, Excitation
Abstract

The Heterodyne Instrument for the Far Infrared (HIFI) onboard the Herschel Space Observatory allows the first observations of light diatomic molecules at high spectral resolution and in multiple transitions. Here, we report deep integrations using HIFI in different lines of hydrides towards the high-mass star forming region AFGL 2591. Detected are CH, CH+, NH, OH+, H2O+, while NH+ and SH+ have not been detected. All molecules except for CH and CH+ are seen in absorption with low excitation temperatures and at velocities different from the systemic velocity of the protostellar envelope. Surprisingly, the CH(JF,P = 3/2_2,- - 1/2_1,+) and CH+(J = 1 - 0, J = 2 - 1) lines are detected in emission at the systemic velocity. We can assign the absorption features to a foreground cloud and an outflow lobe, while the CH and CH+ emission stems from the envelope. The observed abundance and excitation of CH and CH+ can be explained in the scenario of FUV irradiated outflow walls, where a cavity etched out by the outflow allows protostellar FUV photons to irradiate and heat the envelope at larger distances driving the chemical reactions that produce these molecules., Comment: Accepted for publication in Astronomy and Astrophysics (HIFI first results issue)

Published
2010

39. Detection of OH+ and H2O+ towards Orion KL

Author

Maryvonne Gerin, G. A. Blake, J. Stutzki, Shanshan Yu, S. Wang, Paul Hartogh, D. Johnstone, Thomas F. Giesen, Goutam Chattopadhyay, M. Perault, José Cernicharo, Ryszard Szczerba, Rudolf Schieder, Fabien Daniel, S. D. Lord, Jonas Zmuidzinas, Rafael Bachiller, Nathan R. Crockett, Alexandre Karpov, Neal R. Erickson, William B. Latter, John Gill, N. Harada, C. Joblin, P. Zaal, Marie-Lise Dubernet, Erich Schlecht, David A. Neufeld, P. F. Goldsmith, J. A. Murphy, René Liseau, Eric Herbst, C. Comito, Neil Trappe, H. Gupta, E. A. Bergin, A. C. A. Boogert, D. C. Lis, J. R. Goicoechea, Michael Olberg, Jacob Kooi, Jean-Michel Krieg, Frank Maiwald, W. Baechtold, Laurent Pagani, H. W. Yorke, T. A. Bell, F. F. S. van der Tak, Peter Schilke, Martin Emprechtinger, Cecilia Ceccarelli, Volker Ossenkopf, Stephan Schlemmer, Bengt Larsson, Paul B. Rimmer, W. D. Langer, P. J. Encrenaz, R. H. Lin, S.-L. Qin, N. Honingh, J. C. Pearson, Pierrick Martin, M. Salez, S. Cabrit, Emmanuel Caux, Thomas G. Phillips, Karl M. Menten, Sébastien Maret, Rene Plume, Patrick W. Morris, M. C. Diez-Gonzalez, Jesús Martín-Pintado, L. Nordh, Lorene Samoska, R. Güsten, Holger S. P. Müller, Charlotte Vastel, E. Falgarone, Gary J. Melnick, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Ohio State university Departement of Physic, Colombus, Ohio State University [Columbus] (OSU), Ohio State university Departement of Astronomy, Colombus, Ohio State university Departement of Chemistry, Colombus, foreign laboratories (FL), CERN [Genève], Ohio State Univ, Dept Phys, Columbus, OH 43210 USA, Ohio State Univ, Dept Astron & Chem, Columbus, OH 43210 USA, Ohio State University Dept Chemistry, Department of Astronomy [Ann Arbor], University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University-Smithsonian Institution, Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Millimeter-Wave Electronics Laboratory [ETH Zürich] (MWE), Department of Information Technology and Electrical Engineering [Zürich] (D-ITET), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), CNRS INSU, UMR 5187, F-31028 Toulouse 4, France, UMR 5187 Toulouse, Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Max Planck Institute for Radio Astronomy, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL), Laboratoire de Radioastronomie (LRA), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Cahill Center for Astronomy and Astrophysics, California Institute of Technology (CALTECH), Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, BC V9E 2E7 Canada, Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, Laboratoire de Modélisation Multi-échelles des Combustibles (LM2C), Service d'Etudes de Simulation du Comportement du combustibles (SESC), Département d'Etudes des Combustibles (DEC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Département d'Etudes des Combustibles (DEC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Max-Planck-Institut für Radioastronomie (MPIFR), Infrared Processing and Analysis Center (IPAC), Onsala Space Observatory, Chalmers University of Technology [Göteborg], Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), SRON Netherlands Institute for Space Research (SRON), Department of Physics and Astronomy [Calgary], University of Calgary, I. Physikalisches Institut [Köln], Universität zu Köln = University of Cologne, Laboratoire de Didactique André Revuz (LDAR (EA_4434)), Université d'Artois (UA)-Université Paris Diderot - Paris 7 (UPD7)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, A.M.Obukhov Institute of Atmospheric Physics (IAP), Russian Academy of Sciences [Moscow] (RAS), Harvard University [Cambridge]-Smithsonian Institution, Univ Toulouse UPS, Ctr Etud Spatiale Rayonnements, F-31062 Toulouse 9, France, Centre Etud Spatiale Rayonnements Toulouse, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA, CALTECH, Ctr Infrared Proc & Anal, Pasadena, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Universität zu Köln, Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Université Paris Diderot - Paris 7 (UPD7)-Université d'Artois (UA), Max-Planck-Institut für Sonnensystemforschung (MPS), Department of Physics [Columbus], Department of Astronomy [Columbus], Department chemistry and Biochemistry [Columbus], Department of Physics and Astronomy [Baltimore], Johns Hopkins University (JHU), Smithsonian Institution-Harvard University [Cambridge], Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Observatorio de Yebes, Instituto Geografico Nacional (IGN), Laboratoire de Physique Moleculaire pour l'Atmosphere et l'Astrophysique (LPMAA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Ctr Astrobiol CSIC INTA, Lab Astrofis Mol, Madrid 28850, Spain, Ctr Astrobiol CSIC INTA, Lab Astrofis Mol, Madrid, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), CEA-Direction de l'Energie Nucléaire (CEA-DEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction de l'Energie Nucléaire (CEA-DEN), Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany, Univ Cologne, Inst Phys 1, and Astronomy

Subjects
[PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], HERSCHEL OBSERVATIONS, Analytical chemistry, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, LINE, Astrophysics, LASER MAGNETIC-RESONANCE, 7. Clean energy, 01 natural sciences, ISM: abundances, outflows, Ion, STAR-FORMATION, REGION, NEBULA, Ionization, 0103 physical sciences, Absorption (logic), 010306 general physics, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Physics, SPECTROSCOPY, astrochemistry, Astronomy and Astrophysics, INTERSTELLAR H3O+, Astrophysics - Astrophysics of Galaxies, DIFFUSE CLOUDS, molecular processes, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], 13. Climate action, Space and Planetary Science, COMET-KOHOUTEK, Astrophysics of Galaxies (astro-ph.GA), stars: winds, submillimeter: ISM, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Order of magnitude, line: identification
Abstract

We report observations of the reactive molecular ions OH$^+$, H$_2$O$^+$, and H$_3$O$^+$ towards Orion KL with Herschel/HIFI. All three $N=1-0$ fine-structure transitions of OH$^+$ at 909, 971, and 1033GHz and both fine-structure components of the doublet {\it ortho}-H$_2$O$^+$ $1_{11}-0_{00}$ transition at 1115 and 1139GHz were detected; an upper limit was obtained for H$_3$O$^+$. OH$^+$ and H$_2$O$^+$ are observed purely in absorption, showing a narrow component at the source velocity of 9 kms$^{-1}$, and a broad blueshifted absorption similar to that reported recently for HF and {\it para}-H$_{2}^{18}$O, and attributed to the low velocity outflow of Orion KL. We estimate column densities of OH$^+$ and H$_2$O$^+$ for the 9 km s$^{-1}$ component of $9 \pm 3 \times 10^{12}$cm$^{-2}$ and $7 \pm 2 \times 10^{12}$cm$^{-2}$, and those in the outflow of $1.9 \pm 0.7 \times 10^{13}$cm$^{-2}$ and $1.0 \pm 0.3 \times 10^{13}$cm$^{-2}$. Upper limits of $2.4\times 10^{12}$cm$^{-2}$ and $8.7\times 10^{12}$cm$^{-2}$ were derived for the column densities of {\it ortho} and {\it para}-H$_3$O$^+$ from transitions near 985 and 1657GHz. The column densities of the three ions are up to an order of magnitude lower than those obtained from recent observations of W31C and W49N. The comparatively low column densities may be explained by a higher gas density despite the assumption of a very high ionization rate., 5 pages, 1 figure. Accepted to and to be published in the Herschel HIFI special issue of A\&A Letters

Published
2010

40. Herschel/HIFI deepens the circumstellar NH3 enigma

Author

D. Teyssier, Hans Olofsson, Emmanuel Caux, Friedrich Wyrowski, E. De Beck, Carsten Dominik, Thomas G. Phillips, A. Marston, J. Alcolea, Kay Justtanont, Valentin Bujarrabal, Patrick W. Morris, David A. Neufeld, Ryszard Szczerba, K. Edwards, L. B. F. M. Waters, F. L. Schoeier, José Cernicharo, M. Salez, M. R. Schmidt, Karl M. Menten, L. Decin, A. de Koter, P. Planesas, Gary J. Melnick, Michael Olberg, Low Energy Astrophysics (API, FNWI), Astrophysics, Afd Astrophysics begr 1/1/17, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Géosciences Environnement Toulouse (GET)

Subjects
Chemical models, Astronomy, INFRARED OBSERVATIONS, FOS: Physical sciences, Astrophysics, stars: AGB and post-AGB, circumstellar matter, Far infrared, INVERSION LINES, WATER, IRC+10216, Solar and Stellar Astrophysics (astro-ph.SR), Physics, Very large array, INTERSTELLAR AMMONIA, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Research Programm of Institute for Mathematics, Astrophysics and Particle Physics, Radiative transfer modeling, Astronomy and Astrophysics, supergiants, MASS-LOSS, Stars, Astrophysics - Solar and Stellar Astrophysics, [SDU]Sciences of the Universe [physics], Space and Planetary Science, BEARING MOLECULES, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Spatial extent, Ground state, VY CANIS MAJORIS, EMISSION, STARS
Abstract

Circumstellar envelopes (CSEs) of a variety of evolved stars have been found to contain ammonia (NH3) in amounts that exceed predictions from conventional chemical models by many orders of magnitude. The observations reported here were performed in order to better constrain the NH3 abundance in the CSEs of four, quite diverse, oxygen-rich stars using the NH3 ortho J_K = 1_0 - 0_0 ground-state line. We used the Heterodyne Instrument for the Far Infrared aboard Herschel to observe the NH3 J_K = 1_0 - 0_0 transition near 572.5 GHz, simultaneously with the ortho-H2O J_Ka,Kc = 1_1,0 -1_0,1 transition, toward VY CMa, OH 26.5+0.6, IRC+10420, and IK Tau. We conducted non-LTE radiative transfer modeling with the goal to derive the NH3 abundance in these objects' CSEs. For the latter two stars, Very Large Array imaging of NH3 radio-wavelength inversion lines were used to provide further constraints, particularly on the spatial extent of the NH3-emitting regions. Results. We find remarkably strong NH3 emission in all of our objects with the NH3 line intensities rivaling those obtained for the ground state H2O line. The NH3 abundances relative to H2 are very high and range from 2 x 10-7 to 3 x 10-6 for the objects we have studied. Our observations confirm and even deepen the circumstellar NH3 enigma. While our radiative transfer modeling does not yield satisfactory fits to the observed line profiles, it leads to abundance estimates that confirm the very high values found in earlier studies. New ways to tackle this mystery will include further Herschel observations of more NH3 lines and imaging with the Expanded Very Large Array., Comment: 4+2 pages

Published
2010

41. Sensitive limits on the abundance of cold water vapor in the DM Tau protoplanetary disk

Author

T. A. Bell, Per Bjerkeli, A. Baudry, E. F. van Dishoeck, Friedrich Wyrowski, J. Santiago-Garcia, Jeffrey K. J. Fogel, Christian Brinch, D. Johnstone, Rene Plume, Fabien Daniel, Christophe Risacher, S. Bruderer, David A. Neufeld, Steven D. Doty, R. Shipman, J. Stutzki, Paola Caselli, Olja Panić, G. J. Herczeg, A. Fuente, Aggm Tielens, J. R. Goicoechea, Michael Olberg, G. A. Blake, C. Codella, E. A. Bergin, M. Fich, Bengt Larsson, Th. de Graauw, Berengere Parise, René Liseau, Rafael Bachiller, M. Benedettini, Paul Hartogh, Brunella Nisini, J. C. Pearson, Ryszard Szczerba, Mario Tafalla, Jes K. Jørgensen, F. F. S. van der Tak, Umut A. Yildiz, Michiel R. Hogerheijde, T. A. van Kempen, M. Marseille, Carsten Dominik, Frank Helmich, J. Braine, P. J. Encrenaz, Arnold O. Benz, Sylvain Bontemps, Susanne F. Wampfler, Fabrice Herpin, C. McCoey, P. Saraceno, Lars E. Kristensen, R. Visser, Teresa Giannini, José Cernicharo, T. Jacq, Willem Jellema, Gary J. Melnick, A. M. di Giorgio, Dariusz C. Lis, Low Energy Astrophysics (API, FNWI), Astronomy, Kapteyn Astronomical Institute, Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Civilisations atlantiques & Archéosciences (C2A), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ministère de la Culture et de la Communication (MCC)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Université de Nantes - UFR Histoire, Histoire de l'Art et Archéologie (UFR HHAA), Université de Nantes (UN)-Université de Nantes (UN), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), SRON Netherlands Institute for Space Research (SRON), INAF - Osservatorio Astronomico di Roma (OAR), Onsala Space Observatory, Chalmers University of Technology [Göteborg], Centre d'étude spatiale des rayonnements (CESR), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, ESO, European Southern Observatory (ESO), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), Max-Planck-Institut für Radioastronomie (MPIFR), Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Harvard University-Smithsonian Institution, Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), École normale supérieure - Paris (ENS-PSL), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Smithsonian Institution-Harvard University [Cambridge], Université de Nantes - UFR Histoire, Histoire de l'Art et Archéologie (UFR HHAA), and Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture et de la Communication (MCC)

Subjects
DESORPTION, Abundance (chemistry), [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astronomy, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, DUST, Astrophysics, Protoplanetary disk, 01 natural sciences, ISM: abundances, MOLECULES, PLANET-FORMING REGION, CIRCUMSTELLAR DISKS, 0103 physical sciences, H2O, SPECTRA, Solar and Stellar Astrophysics, Emission spectrum, 010306 general physics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Line (formation), Physics, Earth and Planetary Astrophysics (astro-ph.EP), Spectrometer, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Research Programm of Institute for Mathematics, Astrophysics and Particle Physics, protoplanetary disks, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], ISM: molecules, EVOLUTION, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, GAS, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Earth and Planetary Astrophysics, Water ice, Water vapor, Intensity (heat transfer), STARS, Astrophysics - Earth and Planetary Astrophysics
Abstract

We performed a sensitive search for the ground-state emission lines of ortho- and para-water vapor in the DM Tau protoplanetary disk using the Herschel/HIFI instrument. No strong lines are detected down to 3sigma levels in 0.5 km/s channels of 4.2 mK for the 1_{10}--1_{01} line and 12.6 mK for the 1_{11}--0_{00} line. We report a very tentative detection, however, of the 1_{10}--1_{01} line in the Wide Band Spectrometer, with a strength of T_{mb}=2.7 mK, a width of 5.6 km/s and an integrated intensity of 16.0 mK km/s. The latter constitutes a 6sigma detection. Regardless of the reality of this tentative detection, model calculations indicate that our sensitive limits on the line strengths preclude efficient desorption of water in the UV illuminated regions of the disk. We hypothesize that more than 95-99% of the water ice is locked up in coagulated grains that have settled to the midplane., 5 pages, 3 figures. Accepted for publication in the Herschel HIFI special issue of A&A

Published
2010

42. The first spectral line surveys searching for signals from the Dark Ages

Author

Aa. Sandqvist, M. Signore, Gustaf Rydbeck, Pierre Encrenaz, J. Y. Daniel, Carina M. Persson, Åke Hjalmarson, Roberto Maoli, Urban Frisk, and Michael Olberg

Subjects
Structure formation, Cosmology and Nongalactic Astrophysics (astro-ph.CO), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Spectral line, GAMMA-RAY BURST, STAR-FORMATION, MICROWAVE BACKGROUND SPECTRUM, cosmology: observations, early universe, ism: molecules, large scale structure of the universe, large-scale structure of universe, line formation, line: formation, submillimeter: ism, Emission spectrum, PRIMORDIAL GAS, Astrophysics::Galaxy Astrophysics, Physics, COSMIC cancer database, COSMOLOGICAL HYDROGEN RECOMBINATION, Star formation, Astronomy and Astrophysics, early Universe, ISM: molecules, MOLECULAR GAS, Redshift, ODIN SATELLITE, Stars, Space and Planetary Science, Dark Ages, submillimeter: ISM, large-scale structure of Universe, GALAXY FORMATION, HIGH-REDSHIFT, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

Our aim is to observationally investigate the cosmic Dark Ages in order to constrain star and structure formation models, as well as the chemical evolution in the early Universe. Spectral lines from atoms and molecules in primordial perturbations at high redshifts can give information about the conditions in the early universe before and during the formation of the first stars in addition to the epoch of reionisation. The lines may arise from moving primordial perturbations before the formation of the first stars (resonant scattering lines), or could be thermal absorption or emission lines at lower redshifts. The difficulties in these searches are that the source redshift and evolutionary state, as well as molecular species and transition are unknown, which implies that an observed line can fall within a wide range of frequencies. The lines are also expected to be very weak. Observations from space have the advantages of stability and the lack of atmospheric features which is important in such observations. We have therefore, as a first step in our searches, used the Odin satellite to perform two sets of spectral line surveys towards several positions. The first survey covered the band 547-578 GHz towards two positions, and the second one covered the bands 542.0-547.5 GHz and 486.5-492.0 GHz towards six positions selected to test different sizes of the primordial clouds. Two deep searches centred at 543.250 and 543.100 GHz with 1 GHz bandwidth were also performed towards one position. The two lowest rotational transitions of H2 will be redshifted to these frequencies from z~20-30, which is the predicted epoch of the first star formation. No lines are detected at an rms level of 14-90 and 5-35 mK for the two surveys, respectively, and 2-7 mK in the deep searches with a channel spacing of 1-16 MHz. The broad bandwidth covered allows a wide range of redshifts to be explored for a number of atomic and molecular species and transitions. From the theoretical side, our sensitivity analysis show that the largest possible amplitudes of the resonant lines are about 1 mK at frequencies, 15 pages, 9 figures, 3 on-line pages. Accepted for publication in Astronomy & Astrophysics 8 March 2010.

Published
2010

43. The Herschel-Heterodyne Instrument for the Far-Infrared (HIFI)

Author

Brian Jackson, B. Kopf, R. Bieber, R. Güsten, A. M. di Giorgio, J. A. Stern, Holger S. P. Müller, B. J. van Leeuwen, G. S. Liu, R. Orfei, Neal R. Erickson, R. Lai, B. Delforges, Wolfgang Wild, Christian Leinz, O. Coeur-Joly, J. Desbat, David Teyssier, S. D. Lord, Karl Jacobs, Bruce Bumble, Lorene Samoska, M. Rataj, R. H. Lin, Dominicus Kester, M. Salez, X. Tielens, Alexandre Karpov, Paolo Saraceno, K. Edwards, R. Huisman, A. Megej, K. F. Schuster, Michel Fich, L. Dubbeldam, Serguei Cherednichenko, H. Golstein, Christian Monstein, J. A. Murphy, C. van Baaren, Victor Belitsky, P. Planesas, E. Natale, Michael Olberg, Lorenzo Piazzo, T. Peacock, Martin Eggens, Emmanuel Caux, W. A. Hatch, Neil Trappe, Hubregt J. Visser, Herbert Zirath, Jaap Evers, S. Phillip-May, Alain Maestrini, Hamid Javadi, Jacob Kooi, Th. de Graauw, F. Schmülling, E. C. Honingh, C. McCoey, J. C. Pearson, W. Luinge, I. Lopez-Fernandez, W. M. Laauwen, M. Michalska, Bengt Larsson, S. Wulff, John Gill, René Liseau, Volker Ossenkopf, Colin Borys, B. Kruizenga, Rafael Teipen, C. Kramer, A. Cros, H. Goulooze, P. Cais, W. Nowosielski, Goutam Chattopadhyay, M. Stokroos, Rafael Bachiller, F. Zwart, C. Gal, Piotr Orleanski, J. Kawamura, H. Smit, O. Siebertz, H. Aarts, Francesco Nuzzolo, L. Meinsma, Jonas Zmuidzinas, R. Assendorp, D. A. Beintema, H. van de Stadt, Jesús Martín-Pintado, G. de Lange, Ryszard Szczerba, Erich Schlecht, R. Higgins, Christophe Risacher, Patrick W. Morris, H. Jacobs, Christopher Jarchow, Willem Jellema, Pieter Dieleman, Todd Gaier, B. Franke, J. Stutzki, Imran Mehdi, Th. Klein, Harald Franz Arno Merkel, T. Finn, M. Justen, P.R. Wesselius, M. Ciechanowicz, T. M. Klapwijk, Hans-Joachim Wunsch, C. Comito, P. Zaal, Erik L. Kollberg, C. Diez-Gonzalez, T. den Boggende, John Ward, Jian-Rong Gao, Pasquale Cerulli-Irelli, C. Kasemann, T. Kuhn, Frank Helmich, K. Wildeman, Henry G. LeDuc, L. Ravera, Frank Maiwald, Y. Delorme, D. Moratschke, F. Schlöder, J. M. Krieg, M. Olbrich, A. Marston, Juan Daniel Gallego, P.-P. Kooiman, E. Steinmetz, T. Gunsing, A. Naber, M. Melchior, Geert Keizer, M. Schultz, I. Peron, S. Gauffre, C. K. Wafelbakker, N. Whyborn, M. Krause, T. Tils, Alexander Loose, A. de Jonge, Pieter R. Roelfsema, Rudolf Schieder, M. Caris, S. Glenz, A. Barcia, W. Baechtold, Paul Hartogh, R. Shipman, Adwin Boogert, Arnold O. Benz, Thomas G. Phillips, California Institute of Technology (CALTECH), Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre d'étude spatiale des rayonnements (CESR), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Université Sciences et Technologies - Bordeaux 1, Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology [Gothenburg, Sweden], Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Dept Pathol & Microbiol, Université de Montréal (UdeM)-Faculté de médecine vétérinaire, Leibniz Institute for Crystal Growth, Leibniz Institute, Technische Universität Darmstadt (TU Darmstadt), Instituto de RadioAstronomía Milimétrica (IRAM), Centre National de la Recherche Scientifique (CNRS), Institut für Festkörpertheorie, Westfälische Wilhelms-Universität Münster (WWU), Institute of Molecular Medicine and Cell Research (ZBMZ), University of Freiburg [Freiburg], Onsala Space Observatory, Chalmers University of Technology [Göteborg], ESO, European Southern Observatory (ESO), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), Max Planck Institute for Meteorology (MPI-M), Institut für Chemie und Dynamik der Geosphäre - Troposphäre (ICG-2), Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association-Helmholtz-Gemeinschaft = Helmholtz Association, Herschel Science Center [Madrid], European Space Astronomy Centre (ESAC), European Space Agency (ESA)-European Space Agency (ESA), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (1965 - 2019) (UNS), École normale supérieure - Paris (ENS-PSL), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Technische Universität Darmstadt - Technical University of Darmstadt (TU Darmstadt), Westfälische Wilhelms-Universität Münster = University of Münster (WWU), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), TNO Industrie en Techniek, and Astronomy

Subjects
Experimental Physics, Local oscillator, Observatories, Orbits, general [Submillimeter], 01 natural sciences, 7. Clean energy, spectroscopic [Techniques], law.invention, Far infrared, Spectrographs, law, spectrographs [Instrumentation], 010303 astronomy & astrophysics, instrumentation: spectrographs, Physics, Spectrometers, submillimeter: general, Bolometers, Correlators, methods: observational, infrared: general, Heterodyne, Frequency band, Submillimeter: generals, Instantaneous phase, Radio spectrum, Optics, Mixers (machinery), 0103 physical sciences, Frequency bands, observational [Methods], 010306 general physics, Remote sensing, techniques: spectroscopic, Spectrometer, business.industry, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Bolometer, generals [Submillimeter], Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Launching, general [Infrared], Space and Planetary Science, Heterodyning, Instruments, business
Abstract

International audience; Aims: This paper describes the Heterodyne Instrument for the Far-Infrared (HIFI) that was launched onboard ESA's Herschel Space Observatory in May 2009. Methods: The instrument is a set of 7 heterodyne receivers that are electronically tuneable, covering 480-1250 GHz with SIS mixers and the 1410-1910 GHz range with hot electron bolometer (HEB) mixers. The local oscillator (LO) subsystem comprises a Ka-band synthesizer followed by 14 chains of frequency multipliers and 2 chains for each frequency band. A pair of auto-correlators and a pair of acousto-optical spectrometers process the two IF signals from the dual-polarization, single-pixel front-ends to provide instantaneous frequency coverage of 2 × 4 GHz, with a set of resolutions (125 kHz to 1 MHz) that are better than 0.1 km s-1. Results: After a successful qualification and a pre-launch TB/TV test program, the flight instrument is now in-orbit and completed successfully the commissioning and performance verification phase. The in-orbit performance of the receivers matches the pre-launch sensitivities. We also report on the in-orbit performance of the receivers and some first results of HIFI's operations. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

Published
2010

44. Ortho-to-para ratio of interstellar heavy water*

Author

J. M. Krieg, Alexandre Faure, A. Klotz, S. D. Lord, Paul F. Goldsmith, E. Herbst, Alain Castets, M. Salez, Laurent Pagani, Michael Olberg, William D. Langer, Peter Schilke, J. C. Pearson, T. Jacq, Cecilia Ceccarelli, Tom Bell, A. Lorenzani, F. F. S. van der Tak, Pierre Hily-Blant, Laurent Wiesenfeld, Sébastien Maret, Claudine Kahane, Carsten Dominik, Frank Helmich, Asunción Fuente, Pierre Encrenaz, Berengere Parise, Valentine Wakelam, M. H. D. van der Wiel, Charlotte Vastel, P. Cais, S. Cabrit, Thomas G. Phillips, Harold W. Yorke, Aurore Bacmann, Milena Benedettini, Patrick Hennebelle, Edith Falgarone, Edwin A. Bergin, Claudio Codella, Yohann Scribano, Adam Walters, Adwin Boogert, L. Ravera, S. Pacheco, Thomas Henning, G. Melnick, X. Tielens, Paolo Saraceno, Friedrich Wyrowski, David A. Neufeld, Dariusz C. Lis, Audrey Coutens, Karl Schuster, N. Crimier, Emmanuel Caux, Claudia Comito, Brunella Nisini, Paola Caselli, Geoffrey A. Blake, Maryvonne Gerin, José Cernicharo, Serena Viti, Mihkel Kama, Bertrand Lefloch, Alain Baudry, K. Demyk, Sandrine Bottinelli, Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), CNRS INSU, UMR 5187, F-31028 Toulouse 4, France, UMR 5187 Toulouse, Univ Toulouse UPS, Ctr Etud Spatiale Rayonnements, F-31062 Toulouse 9, France, Centre Etud Spatiale Rayonnements Toulouse, Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Centre d'étude spatiale des rayonnements (CESR), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, FORMATION STELLAIRE 2010, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), Department of Astronomy [Ann Arbor], University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Radioastronomie (LRA), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD), I. Physikalisches Institut [Köln], Universität zu Köln, Max Planck Institute for Radio Astronomy, AMOR 2010, INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Ohio State Univ, Dept Phys, Columbus, OH 43210 USA, Ohio State University [Columbus] (OSU), Ohio State Univ, Dept Astron & Chem, Columbus, OH 43210 USA, INAF - Osservatorio Astronomico di Roma (OAR), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), Max-Planck-Institut für Radioastronomie (MPIFR), Onsala Space Observatory, Chalmers University of Technology [Göteborg], Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), Universität zu Köln = University of Cologne, National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Ctr Astrobiol CSIC INTA, Lab Astrofis Mol, Madrid 28850, Spain, Ctr Astrobiol CSIC INTA, Lab Astrofis Mol, Madrid, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany, Univ Cologne, Inst Phys 1, Osservatorio di Astrofisica di Roma (OAR), Low Energy Astrophysics (API, FNWI), and Astronomy

Subjects
Opacity, Astronomy, FOS: Physical sciences, Astrophysics, 01 natural sciences, ISM: abundances, PROTOSTAR IRAS 16293-2422, 0103 physical sciences, Protostar, Spectral resolution, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), ComputingMilieux_MISCELLANEOUS, Line (formation), ENVELOPE, Physics, SPECTROSCOPY, 010304 chemical physics, Research Programm of Institute for Mathematics, Astrophysics and Particle Physics, astrochemistry, CONSTRAINTS, Astronomy and Astrophysics, ISM: molecules, Galaxy, Interstellar medium, molecular processes, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Deuterium, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, submillimeter: ISM, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], line: identification
Abstract

Despite the low elemental deuterium abundance in the Galaxy, enhanced molecular D/H ratios have been found in the environments of low-mass star forming regions, and in particular the Class 0 protostar IRAS 16293-2422. The CHESS (Chemical HErschel Surveys of Star forming regions) Key Program aims at studying the molecular complexity of the interstellar medium. The high sensitivity and spectral resolution of the HIFI instrument provide a unique opportunity to observe the fundamental 1,1,1 - 0,0,0 transition of the ortho-D2O molecule, inaccessible from the ground, and to determine the ortho-to-para D2O ratio. We have detected the fundamental transition of the ortho-D2O molecule at 607.35 GHz towards IRAS 16293-2422. The line is seen in absorption with a line opacity of 0.62 +/- 0.11 (1 sigma). From the previous ground-based observations of the fundamental 1,1,0 - 1,0,1 transition of para-D2O seen in absorption at 316.80 GHz we estimate a line opacity of 0.26 +/- 0.05 (1 sigma). We show that the observed absorption is caused by the cold gas in the envelope of the protostar. Using these new observations, we estimate for the first time the ortho to para D2O ratio to be lower than 2.6 at a 3 sigma level of uncertainty, to be compared with the thermal equilibrium value of 2:1., 5 pages, 5 figures, accepted the A&A HIFI Special Issue as a letter

Published
2010

45. Ground-state ammonia and water in absorption towards Sgr B2

Author

John H. Black, Pierre Encrenaz, Michael Olberg, A. O. H. Olofsson, Eva Wirström, Åke Hjalmarson, Urban Frisk, Aa. Sandqvist, Edith Falgarone, B. Larsson, Per Bergman, Onsala Space Observatory, Chalmers University of Technology (OSO), Stockholm Observatory, AlbaNova University Center, Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Instrumentation et télédétection, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Dynamique des milieux interstellaires et plasmas stellaires, and Swedish Space Corporation (SSC)

Subjects
Physics, Molecular cloud, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Space and Planetary Science, Nucleosynthesis, Astrophysics of Galaxies (astro-ph.GA), Isotopologue, Disc, Absorption (electromagnetic radiation), Ground state, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Line (formation)
Abstract

We have used the Odin submillimetre-wave satellite telescope to observe the ground state transitions of ortho-ammonia and ortho-water, including their 15N, 18O, and 17O isotopologues, towards Sgr B2. The extensive simultaneous velocity coverage of the observations, >500 km/s, ensures that we can probe the conditions of both the warm, dense gas of the molecular cloud Sgr B2 near the Galactic centre, and the more diffuse gas in the Galactic disk clouds along the line-of-sight. We present ground-state NH3 absorption in seven distinct velocity features along the line-of-sight towards Sgr B2. We find a nearly linear correlation between the column densities of NH3 and CS, and a square-root relation to N2H+. The ammonia abundance in these diffuse Galactic disk clouds is estimated to be about (0.5-1)e-8, similar to that observed for diffuse clouds in the outer Galaxy. On the basis of the detection of H218O absorption in the 3 kpc arm, and the absence of such a feature in the H217O spectrum, we conclude that the water abundance is around 1e-7, compared to ~1e-8 for NH3. The Sgr B2 molecular cloud itself is seen in absorption in NH3, 15NH3, H2O, H218O, and H217O, with emission superimposed on the absorption in the main isotopologues. The non-LTE excitation of NH3 in the environment of Sgr B2 can be explained without invoking an unusually hot (500 K) molecular layer. A hot layer is similarly not required to explain the line profiles of the 1_{1,0}-1_{0,1} transition from H2O and its isotopologues. The relatively weak 15NH3 absorption in the Sgr B2 molecular cloud indicates a high [14N/15N] isotopic ratio >600. The abundance ratio of H218O and H217O is found to be relatively low, 2.5--3. These results together indicate that the dominant nucleosynthesis process in the Galactic centre is CNO hydrogen burning., 10 pages, 5 figures

Published
2010

46. Herschel observations of EXtra-Ordinary Sources (HEXOS): detecting spiral arm clouds by CH absorption lines

Author

R. Bachille, T. A. Bell, H. Gupta, A. C. A. Boogert, H. W. Yorke, Martin Emprechtinger, Nathan R. Crockett, Cecilia Ceccarelli, P. J. Encrenaz, M. Perault, José Cernicharo, Laurent Pagani, Volker Ossenkopf, Eric Herbst, R. Rolffs, D. C. Lis, Pierrick Martin, Thomas F. Giesen, Emmanuel Caux, C. Joblin, E. Falgarone, Karl M. Menten, D. Johnstone, S.-L. Qin, T. Möller, Gary J. Melnick, Peter Schilke, J. R. Goicoechea, Michael Olberg, M. Salez, Sébastien Maret, Rene Plume, Jacob Kooi, Stephan Schlemmer, Patrick W. Morris, Jesús Martín-Pintado, Thomas G. Phillips, J. C. Pearson, W. Baechtold, Arnaud Belloche, Goutam Chattopadhyay, S. D. Lord, Alexandre Karpov, N. Honingh, Charlotte Vastel, C. Comito, E. A. Bergin, Neil Trappe, J. L. Gill, J. Stutzki, J.-M. Krieg, Fabien Daniel, L. H. Nordh, Jonas Zmuidzinas, S. Cabrit, M. C. Diez-Gonzalez, Maryvonne Gerin, Rudolf Schieder, F. F. S. van der Tak, Paul Hartogh, W. D. Langer, Marie-Lise Dubernet, S. Wang, G. A. Blake, Shanshan Yu, R. Güsten, Holger S. P. Müller, David A. Neufeld, P. F. Goldsmith, J. A. Murphy, Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), I. Physikalisches Institut [Köln], Universität zu Köln, Max Planck Institute for Radio Astronomy, Hamburger Synchrotronstrahlungslabor HASYLAB at Deutsches Elektronen Synchrotron DESY (HASYLAB), Deutsches Elektronen-Synchrotron [Hamburg] (DESY), Université de Cologne, Institut de Physique 1, Université de Cologne, Max-Planck-Institut für Radioastronomie (MPIFR), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), California Institute of Technology (CALTECH), Department of Astronomy [Ann Arbor], University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Univ Toulouse UPS, Ctr Etud Spatiale Rayonnements, F-31062 Toulouse 9, France, Centre Etud Spatiale Rayonnements Toulouse, CNRS INSU, UMR 5187, F-31028 Toulouse 4, France, UMR 5187 Toulouse, Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Université Paris sciences et lettres (PSL), Cahill Center for Astronomy and Astrophysics, Laboratoire de Radioastronomie (LRA), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Ohio State Univ, Dept Phys, Columbus, OH 43210 USA, Ohio State University [Columbus] (OSU), Ohio State Univ, Dept Astron & Chem, Columbus, OH 43210 USA, Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, BC V9E 2E7 Canada, Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, Laboratoire de Modélisation Multi-échelles des Combustibles (LM2C), Service d'Etudes de Simulation du Comportement du combustibles (SESC), Département d'Etudes des Combustibles (DEC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Département d'Etudes des Combustibles (DEC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA, CALTECH, Ctr Infrared Proc & Anal, Pasadena, Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), SRON Netherlands Institute for Space Research (SRON), foreign laboratories (FL), CERN [Genève], Department of Physics and Astronomy [Calgary], University of Calgary, Laboratoire de Didactique André Revuz (LDAR (EA_4434)), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Université Paris Diderot - Paris 7 (UPD7)-Université d'Artois (UA), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, A.M.Obukhov Institute of Atmospheric Physics (IAP), Russian Academy of Sciences [Moscow] (RAS), Millimeter-Wave Electronics Laboratory [ETH Zürich] (MWE), Department of Information Technology and Electrical Engineering [Zürich] (D-ITET), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Onsala Space Observatory, Chalmers University of Technology [Göteborg], Faure, Alexandre, Universität zu Köln = University of Cologne, École normale supérieure - Paris (ENS-PSL), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Harvard University-Smithsonian Institution, Infrared Processing and Analysis Center (IPAC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université d'Artois (UA)-Université Paris Diderot - Paris 7 (UPD7)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany, Univ Cologne, Inst Phys 1, École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Ctr Astrobiol CSIC INTA, Lab Astrofis Mol, Madrid 28850, Spain, Ctr Astrobiol CSIC INTA, Lab Astrofis Mol, Madrid, Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), California Institute of Technology (CALTECH)-NASA, CEA-Direction de l'Energie Nucléaire (CEA-DEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction de l'Energie Nucléaire (CEA-DEN), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), and Astronomy

Subjects
Physics, Spiral galaxy, 010504 meteorology & atmospheric sciences, Absorption spectroscopy, Experimental Physics, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Line width, Astrophysics - Astrophysics of Galaxies, Galaxy, ISM: abundances, ISM: molecules, Linear relationship, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Spectral resolution, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

We have observed CH absorption lines ($J=3/2, N=1 \leftarrow J=1/2, N=1$) against the continuum source Sgr~B2(M) using the \textit{Herschel}/HIFI instrument. With the high spectral resolution and wide velocity coverage provided by HIFI, 31 CH absorption features with different radial velocities and line widths are detected and identified. The narrower line width and lower column density clouds show `spiral arm' cloud characteristics, while the absorption component with the broadest line width and highest column density corresponds to the gas from the Sgr~B2 envelope. The observations show that each `spiral arm' harbors multiple velocity components, indicating that the clouds are not uniform and that they have internal structure. This line-of-sight through almost the entire Galaxy offers unique possibilities to study the basic chemistry of simple molecules in diffuse clouds, as a variety of different cloud classes are sampled simultaneously. We find that the linear relationship between CH and H$_2$ column densities found at lower $A_V$ by UV observations does not continue into the range of higher visual extinction. There, the curve flattens, which probably means that CH is depleted in the denser cores of these clouds., Comment: Accepted for publication in A&A, HIFI Special Issue

Published
2010

47. Herschel-PACS spectroscopy of the intermediate mass protostar NGC7129 FIRS 2

Author

Steven D. Doty, G. J. Herczeg, R. Shipman, E. A. Bergin, Volker Ossenkopf, R. Visser, A. Baudry, J. R. Goicoechea, Berengere Parise, A. M. di Giorgio, Michael Olberg, M. Justen, Th. de Graauw, Rafael Bachiller, W. Luinge, Fabrice Herpin, Brunella Nisini, Susanne F. Wampfler, Paola Caselli, Per Bjerkeli, Carsten Dominik, P. J. Encrenaz, Hamid Javadi, C. McCoey, Rene Plume, J. Braine, J.J. Gill, M. Fich, Frank Helmich, M. Benedettini, Friedrich Wyrowski, W. M. Laauwen, T. Jacq, M. Marseille, D. Johnstone, Umut A. Yildiz, A. Fuente, P. Saraceno, Gary J. Melnick, Sylvain Bontemps, E. F. van Dishoeck, F. F. S. van der Tak, René Liseau, John E. Pearson, P. Gaufre, Michiel R. Hogerheijde, T. A. van Kempen, Christophe Risacher, J. Santiago, D. C. Lis, G. A. Blake, C. Codella, Mario Tafalla, Arnold O. Benz, Fabien Daniel, S. Bruderer, Bengt Larsson, Jes K. Jørgensen, José Cernicharo, Lars E. Kristensen, Teresa Giannini, Low Energy Astrophysics (API, FNWI), Astronomy, INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), SRON Netherlands Institute for Space Research (SRON), INAF - Osservatorio Astronomico di Roma (OAR), Onsala Space Observatory, Chalmers University of Technology [Göteborg], Centre d'étude spatiale des rayonnements (CESR), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, ESO, European Southern Observatory (ESO), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), Max-Planck-Institut für Radioastronomie (MPIFR), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), École normale supérieure - Paris (ENS-PSL), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)

Subjects
Astronomy, FOS: Physical sciences, Astrophysics, I, 01 natural sciences, Spectral line, STAR-FORMATION, 0103 physical sciences, Protostar, OUTFLOW, Emission spectrum, 010306 general physics, Spectroscopy, 010303 astronomy & astrophysics, Envelope (waves), Line (formation), QB, Physics, stars: formation, Research Programm of Institute for Mathematics, Astrophysics and Particle Physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy and Astrophysics, Spectral bands, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], YOUNG STELLAR OBJECTS, REGIONS, Astrophysics - Astrophysics of Galaxies, ISM: molecules, EVOLUTION, Orders of magnitude (time), 13. Climate action, Space and Planetary Science, GAS, Astrophysics of Galaxies (astro-ph.GA), ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Galaxy Astrophysics, HH 46
Abstract

Aims: We present preliminary results of the first Herschel spectroscopic observations of NGC7129 FIRS2, an intermediate mass star-forming region. We attempt to interpret the observations in the framework of an in-falling spherical envelope. Methods: The PACS instrument was used in line spectroscopy mode (R=1000-5000) with 15 spectral bands between 63 and 185 microns. This provided good detections of 26 spectral lines seen in emission, including lines of H2O, CO, OH, O I, and C II. Results: Most of the detected lines, particularly those of H2O and CO, are substantially stronger than predicted by the spherical envelope models, typically by several orders of magnitude. In this paper we focus on what can be learned from the detected CO emission lines. Conclusions: It is unlikely that the much stronger than expected line emission arises in the (spherical) envelope of the YSO. The region hot enough to produce such high excitation lines within such an envelope is too small to produce the amount of emission observed. Virtually all of this high excitation emission must arise in structures such as as along the walls of the outflow cavity with the emission produced by a combination of UV photon heating and/or non-dissociative shocks., Comment: A&A Special Issue on Herschel

Published
2010
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48. Herschel observations of deuterated water towards Sgr B2(M)

Author

René Liseau, Peter Schilke, C. Joblin, R. Rolffs, S. D. Lord, T. A. Bell, Stephan Schlemmer, J. A. Murphy, H. S. P. Mueller, Martin Emprechtinger, David A. Neufeld, S. Wang, P. F. Goldsmith, D. Johnstone, Nathan R. Crockett, Erich Schlecht, Charlotte Vastel, Karl M. Menten, Eric Herbst, Emmanuel Caux, Michael Olberg, F. F. S. van der Tak, R. H. Lin, J. C. Pearson, Claudia Comito, Neil Trappe, Shanshan Yu, Javier R. Goicoechea, S.-L. Qin, Sébastien Maret, Ryszard Szczerba, Gary J. Melnick, Rene Plume, Peter G. Martin, Maryvonne Gerin, H. W. Yorke, M. Perault, José Cernicharo, H. Gupta, Cecilia Ceccarelli, Thomas G. Phillips, Lorene Samoska, W. D. Latter, W. D. Langer, Marie-Lise Dubernet, J. Stutzki, Patrick W. Morris, Dariusz C. Lis, Thomas F. Giesen, Geoffrey A. Blake, P. J. Encrenaz, Volker Ossenkopf, Arnaud Belloche, Edwin A. Bergin, Bengt Larsson, Fabien Daniel, Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Astronomy, Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, Experimental Physics, Monte Carlo method, FOS: Physical sciences, Astrophysics, 01 natural sciences, Outer core, BAND, Gas phase, HOT CORES, 0103 physical sciences, EXCITATION, Inner envelope, Radiative transfer, SAGITTARIUS-B2, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], ASTRONOMY, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, LINE OBSERVATIONS, 6. Clean water, ISM: molecules, molecular processes, Deuterium, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics of Galaxies (astro-ph.GA), VAPOR, line: formation, SUBMILLIMETER
Abstract

Observations of HDO are an important complement for studies of water, because they give strong constraints on the formation processes -- grain surfaces versus energetic process in the gas phase, e.g. in shocks. The HIFI observations of multiple transitions of HDO in Sgr~B2(M) presented here allow the determination of the HDO abundance throughout the envelope, which has not been possible before with ground-based observations only. The abundance structure has been modeled with the spherical Monte Carlo radiative transfer code RATRAN, which also takes radiative pumping by continuum emission from dust into account. The modeling reveals that the abundance of HDO rises steeply with temperature from a low abundance ($2.5\times 10^{-11}$) in the outer envelope at temperatures below 100~K through a medium abundance ($1.5\times 10^{-9}$) in the inner envelope/outer core, at temperatures between 100 and 200~K, and finally a high abundance ($3.5\times 10^{-9}$) at temperatures above 200~K in the hot core., Comment: A&A HIFI special issue, accepted

Published
2010

49. Herschel/HIFI observations of high-J CO lines in the NGC 1333 low-mass star-forming region

Author

Fabrice Herpin, José Cernicharo, Carsten Dominik, A. Di Giorgio, T. Jacq, Pierre Encrenaz, Doug Johnstone, Claudio Codella, Steven D. Doty, M. Fich, F. F. S. van der Tak, Jes K. Jørgensen, Gregory J. Herczeg, Volker Ossenkopf, Paola Caselli, S. F. Wampfler, M. Marseille, Edwin Bergin, Per Bjerkeli, T. A. van Kempen, Michiel R. Hogerheijde, Sylvain Bontemps, Jonathan Braine, Alain Baudry, Asunción Fuente, Juergen Stutzki, J. Santiago-Garcia, E. Deul, Ruud Visser, Willem Jellema, René Liseau, Javier R. Goicoechea, Paolo Saraceno, Christophe Risacher, Umut A. Yildiz, David A. Neufeld, Berengere Parise, Milena Benedettini, Pieter Dieleman, Frank Helmich, E. F. van Dishoeck, R. Schieder, John C. Pearson, Dariusz C. Lis, Lars E. Kristensen, F.-C. Liu, T. Giannini, Arnold O. Benz, F. Daniel, Friedrich Wyrowski, Rafael Bachiller, Geoffrey A. Blake, Russel Shipman, Alexander G. G. M. Tielens, Th. de Graauw, Michael Olberg, Gary J. Melnick, C. McCoey, B. Larsson, Brunella Nisini, R. Plume, M. Tafalla, Simon Bruderer, Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), SRON Netherlands Institute for Space Research (SRON), INAF - Osservatorio Astronomico di Roma (OAR), Onsala Space Observatory, Chalmers University of Technology [Göteborg], Centre d'étude spatiale des rayonnements (CESR), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, ESO, European Southern Observatory (ESO), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), Max-Planck-Institut für Radioastronomie (MPIFR), Astronomy, Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), École normale supérieure - Paris (ENS-PSL), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), and Low Energy Astrophysics (API, FNWI)

Subjects
010504 meteorology & atmospheric sciences, Astronomy, Evaporation, FOS: Physical sciences, DUST, Astrophysics, Star (graph theory), 01 natural sciences, DENSE CORES, 0103 physical sciences, Radiative transfer, Protostar, WATER, Solar and Stellar Astrophysics, Isotopologue, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), QB, 0105 earth and related environmental sciences, Envelope (waves), Line (formation), Physics, stars: formation, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], astrochemistry, NGC-1333 IRAS-4, PROTOSTARS, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], H2CO, ISM: molecules, EVOLUTION, ENVELOPES, ISM: jets and outflows, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, ABUNDANCE, Low Mass, HIFI
Abstract

Herschel-HIFI observations of high-J lines (up to J_u=10) of 12CO, 13CO and C18O are presented toward three deeply embedded low-mass protostars, NGC 1333 IRAS 2A, IRAS 4A, and IRAS 4B, obtained as part of the Water In Star-forming regions with Herschel (WISH) key program. The spectrally-resolved HIFI data are complemented by ground-based observations of lower-J CO and isotopologue lines. The 12CO 10-9 profiles are dominated by broad (FWHM 25-30 km s^-1) emission. Radiative transfer models are used to constrain the temperature of this shocked gas to 100-200 K. Several CO and 13CO line profiles also reveal a medium-broad component (FWHM 5-10 km s^-1), seen prominently in H2O lines. Column densities for both components are presented, providing a reference for determining abundances of other molecules in the same gas. The narrow C18O 9-8 lines probe the warmer part of the quiescent envelope. Their intensities require a jump in the CO abundance at an evaporation temperature around 25 K, thus providing new direct evidence for a CO ice evaporation zone around low-mass protostars., Comment: 8 pages, 9 figures

Published
2010

50. Water in low-mass star-forming regions with Herschel . HIFI spectroscopy of NGC 1333

Author

Rafael Bachiller, Christophe Risacher, N. Whyborn, Steven D. Doty, A. Baudry, Per Bjerkeli, David A. Neufeld, Rene Plume, R. Shipman, F.-C. Liu, Pieter Dieleman, Sylvain Bontemps, Fabrice Herpin, E. F. van Dishoeck, M. Benedettini, Pieter R. Roelfsema, C. McCoey, José Cernicharo, Paola Caselli, J. Stutzki, Carsten Dominik, Paolo Saraceno, J. Braine, R. Visser, M. Fich, Susanne F. Wampfler, Frank Helmich, C. Codella, A. de Jonge, A. M. di Giorgio, Lars E. Kristensen, Friedrich Wyrowski, Geoffrey A. Blake, Teresa Giannini, E. Deul, Dariusz C. Lis, F. F. S. van der Tak, Volker Ossenkopf, J. Santiago-Garcia, Christian Brinch, M. Marseille, Th. de Graauw, Bengt Larsson, T. Jacq, Umut A. Yildiz, Mario Tafalla, A. Fuente, Jes K. Jørgensen, Arnold O. Benz, Fabien Daniel, Gary J. Melnick, S. Bruderer, Berengere Parise, Brunella Nisini, P. J. Encrenaz, Michiel R. Hogerheijde, T. A. van Kempen, René Liseau, D. A. Beintema, D. Johnstone, Aggm Tielens, J. R. Goicoechea, Michael Olberg, Michael J. Kaufman, J. C. Pearson, G. J. Herczeg, E. A. Bergin, Centre d'étude spatiale des rayonnements (CESR), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Harvard-Smithsonian Center for Astrophysics (CfA), Smithsonian Institution-Harvard University [Cambridge], Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), SRON Netherlands Institute for Space Research (SRON), INAF - Osservatorio Astronomico di Roma (OAR), Onsala Space Observatory, Chalmers University of Technology [Göteborg], ESO, European Southern Observatory (ESO), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), Max-Planck-Institut für Radioastronomie (MPIFR), Astronomy, Low Energy Astrophysics (API, FNWI), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), Harvard University-Smithsonian Institution, École normale supérieure - Paris (ENS-PSL), and National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)

Subjects
010504 meteorology & atmospheric sciences, Astronomy, Young stellar object, FOS: Physical sciences, PROTOSTELLAR ENVELOPES, Astrophysics, PHYSICAL STRUCTURE, 01 natural sciences, DISK, Abundance (ecology), 0103 physical sciences, Protostar, OUTFLOW, Solar and Stellar Astrophysics, Spectroscopy, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Envelope (waves), Line (formation), QB, Physics, stars: formation, astrochemistry, Research Programm of Institute for Mathematics, Astrophysics and Particle Physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], NGC-1333 IRAS-4, PROTOSTARS, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], ISM: molecules, ISM: jets and outflows, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, VAPOR, ABUNDANCE, Outflow, SUBMILLIMETER, EMISSION, Low Mass, ISM: individual objects: NGC 1333
Abstract

'Water In Star-forming regions with Herschel' (WISH) is a key programme dedicated to studying the role of water and related species during the star-formation process and constraining the physical and chemical properties of young stellar objects. The Heterodyne Instrument for the Far-Infrared (HIFI) on the Herschel Space Observatory observed three deeply embedded protostars in the low-mass star-forming region NGC1333 in several H2-16O, H2-18O, and CO transitions. Line profiles are resolved for five H16O transitions in each source, revealing them to be surprisingly complex. The line profiles are decomposed into broad (>20 km/s), medium-broad (~5-10 km/s), and narrow (20 km/s), indicating that its physical origin is the same as for the broad H2-16O component. In one of the sources, IRAS4A, an inverse P Cygni profile is observed, a clear sign of infall in the envelope. From the line profiles alone, it is clear that the bulk of emission arises from shocks, both on small (, Accepted for publication in the A&A HIFI special issue

Published
2010

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