Search

Your search keyword '"Brian Svoboda"' showing total 12 results
Start Over Author "Brian Svoboda" Language english
12 results on '"Brian Svoboda"'

1. Evidence for Jet/Outflow Shocks Heating the Environment around the Class I Protostellar Source Elias 29: FAUST XXI

Author

Yoko Oya, Eri Saiga, Anna Miotello, Maria Koutoulaki, Doug Johnstone, Cecilia Ceccarelli, Claire J. Chandler, Claudio Codella, Nami Sakai, Eleonora Bianchi, Mathilde Bouvier, Steven Charnley, Nicolas Cuello, Marta De Simone, Logan Francis, Tomoyuki Hanawa, Izaskun Jiménez-Serra, Laurent Loinard, Francois Menard, Giovanni Sabatini, Charlotte Vastel, Ziwei Zhang, Yuri Aikawa, Felipe O. Alves, Nadia Balucani, Gemma Busquet, Paola Caselli, Emmanuel Caux, Spandan Choudhury, Francois Dulieu, Aurora Durán, Lucy Evans, Davide Fedele, Siyi Feng, Francesco Fontani, Tetsuya Hama, Eric Herbst, Shingo Hirano, Tomoya Hirota, Andrea Isella, Claudine Kahane, Bertrand Lefloch, Romane Le Gal, Hauyu Baobab Liu, Ana López-Sepulcre, Luke T. Maud, María José Maureira, Seyma Mercimek, George Moellenbrock, Shoji Mori, Hideko Nomura, Yasuhiro Oba, Ross O’Donoghue, Satoshi Ohashi, Yuki Okoda, Juan Ospina-Zamudio, Jaime Pineda, Linda Podio, Albert Rimola, Takeshi Sakai, Dominique Segura-Cox, Yancy Shirley, Brian Svoboda, Leonardo Testi, Serena Viti, Naoki Watanabe, Yoshimasa Watanabe, Yichen Zhang, and Satoshi Yamamoto

Subjects
Astrochemistry, Stellar winds, Star formation, Low mass stars, Protostars, Astrophysics, QB460-466
Abstract

We have observed the late Class I protostellar source Elias 29 at a spatial resolution of 70 au with the Atacama Large Millimeter/submillimeter Array as part of the FAUST Large Program. We focus on the line emission of SO, while that of ^34 SO, C ^18 O, CS, SiO, H ^13 CO ^+ , and DCO ^+ are used supplementarily. The spatial distribution of the SO rotational temperature ( T _rot (SO)) is evaluated by using the intensity ratio of its two rotational excitation lines. Besides in the vicinity of the protostar, two hot spots are found at a distance of 500 au from the protostar; T _rot (SO) locally rises to 53 ${}_{-15}^{+25}$ K at the interaction point of the outflow and the southern ridge, and 72 ${}_{-29}^{+66}$ K within the southeastern outflow probably due to a jet-driven bow shock. However, the SiO emission is not detected at these hot spots. It is likely that active gas accretion through the disk-like structure and onto the protostar still continues even at this evolved protostellar stage, at least sporadically, considering the outflow/jet activities and the possible infall motion previously reported. Interestingly, T _rot (SO) is as high as 20–30 K even within the quiescent part of the southern ridge apart from the protostar by 500–1000 au without clear kinematic indication of current outflow/jet interactions. Such a warm condition is also supported by the low deuterium fractionation ratio of HCO ^+ estimated by using the H ^13 CO ^+ and DCO ^+ lines. The B-type star HD147889 ∼0.5 pc away from Elias 29, previously suggested as a heating source for this region, is likely responsible for the warm condition of Elias 29.

Published
2025
Full Text
View/download PDF

2. Turbulent Pressure Heats Gas and Suppresses Star Formation in Galactic Bar Molecular Clouds

Author

Andy Nilipour, Juergen Ott, David S. Meier, Brian Svoboda, Mattia C. Sormani, Adam Ginsburg, Savannah R. Gramze, Natalie O. Butterfield, and Ralf S. Klessen

Subjects
Interstellar medium, Star formation, Milky Way Galaxy, Molecular clouds, Galactic bar, Astrophysics, QB460-466
Abstract

The Central Molecular Zone (CMZ) of the Milky Way is fed by gas inflows from the Galactic disk along almost radial trajectories aligned with the major axis of the Galactic bar. However, despite being fundamental to all processes in the nucleus of the Galaxy, these inflows have been studied significantly less than the CMZ itself. We present observations of various molecular lines between 215 and 230 GHz for 20 clouds with ∣ ℓ ∣ < 10°, which are candidates for clouds in the Galactic bar due to their warm temperatures and broad lines relative to typical Galactic disk clouds, using the Atacama Large Millimeter/submillimeter Array Atacama Compact Array. We measure gas temperatures, shocks, star formation rates, turbulent Mach numbers, and masses for these clouds. Although some clouds may be in the Galactic disk despite their atypical properties, nine clouds are likely associated with regions in the Galactic bar, and in these clouds, turbulent pressure is suppressing star formation. In clouds with no detected star formation, turbulence is the dominant heating mechanism, whereas photoelectric processes heat the star-forming clouds. We find that the ammonia (NH _3 ) and formaldehyde (H _2 CO) temperatures probe different gas components, and in general, each transition appears to trace different molecular gas phases within the clouds. We also measure the CO-to-H _2 X-factor in the bar to be an order of magnitude lower than the typical Galactic value. These observations provide evidence that molecular clouds achieve CMZ-like properties before reaching the CMZ.

Published
2024
Full Text
View/download PDF

3. CMZoom. IV. Incipient High-mass Star Formation throughout the Central Molecular Zone

Author

H Perry Hatchfield, Cara Battersby, Ashley T. Barnes, Natalie Butterfield, Adam Ginsburg, Jonathan D. Henshaw, Steven N. Longmore, Xing Lu, Brian Svoboda, Daniel Walker, Daniel Callanan, Elisabeth A. C. Mills, Luis C. Ho, Jens Kauffmann, J. M. Diederik Kruijssen, Jürgen Ott, Thushara Pillai, and Qizhou Zhang

Subjects
Star formation, Galactic center, Milky Way Galaxy, Young stellar objects, Protostars, Astrophysics, QB460-466
Abstract

In this work, we constrain the star-forming properties of all possible sites of incipient high-mass star formation in the Milky Way’s Galactic Center. We identify dense structures using the CMZoom 1.3 mm dust continuum catalog of objects with typical radii of ∼0.1 pc, and measure their association with tracers of high-mass star formation. We incorporate compact emission at 8, 21, 24, 25, and 70 μ m from the Midcourse Space Experiment, Spitzer, Herschel, and SOFIA, cataloged young stellar objects, and water and methanol masers to characterize each source. We find an incipient star formation rate (SFR) for the Central Molecular Zone (CMZ) of ∼0.08 M _⊙ yr ^−1 over the next few 10 ^5 yr. We calculate upper and lower limits on the CMZ’s incipient SFR of ∼0.45 and ∼0.05 M _⊙ yr ^−1 ,respectively, spanning roughly equal to and several times greater than other estimates of CMZ’s recent SFR. Despite substantial uncertainties, our results suggest the incipient SFR in the CMZ may be higher than previously estimated. We find that the prevalence of star formation tracers does not correlate with source volume density, but instead ≳75% of high-mass star formation is found in regions above a column density ratio ( N _SMA / N _Herschel ) of ∼1.5. Finally, we highlight the detection of atoll sources , a reoccurring morphology of cold dust encircling evolved infrared sources, possibly representing H ii regions in the process of destroying their envelopes.

Published
2024
Full Text
View/download PDF

4. FAUST. XIV. Probing the Flared Disk in L1527 with Sulfur-bearing Molecules

Author

Ziwei E. Zhang, Nami Sakai, Satoshi Ohashi, Nadia M. Murillo, Claire J. Chandler, Brian Svoboda, Cecilia Ceccarelli, Claudio Codella, Luca Cacciapuoti, Ross O’Donoghue, Serena Viti, Yuri Aikawa, Eleonora Bianchi, Paola Caselli, Steven Charnley, Tomoyuki Hanawa, Izaskun Jímenez-Serra, Hauyu Baobab Liu, Laurent Loinard, Yoko Oya, Linda Podio, Giovanni Sabatini, Charlotte Vastel, and Satoshi Yamamoto

Subjects
Astrochemistry, Interstellar medium, Interstellar molecules, Protostars, Star formation, Astrophysics, QB460-466
Abstract

IRAS04368+2557 in L1527 is a Class 0/I protostar with a clear disk-envelope system revealed by previous Atacama Large Millimeter/submillimeter Array (ALMA) observations. In this paper, we discuss the flared structure of this source with observed sulfur-bearing molecules included in the FAUST ALMA large program. The analyses of molecular distributions and kinematics have shown that CS, SO, and OCS trace different regions of the disk-envelope system. To evaluate the temperature across the disk, we derive rotation temperature with the two observed SO lines. The temperature profile shows a clear, flared “butterfly” structure with the higher temperature being ∼50 K and the central lower temperature region (

Published
2024
Full Text
View/download PDF

5. Chemical and Physical Characterization of the Isolated Protostellar Source CB68: FAUST IV

Author

Muneaki Imai, Yoko Oya, Brian Svoboda, Hauyu Baobab Liu, Bertrand Lefloch, Serena Viti, Yichen Zhang, Cecilia Ceccarelli, Claudio Codella, Claire J. Chandler, Nami Sakai, Yuri Aikawa, Felipe O. Alves, Nadia Balucani, Eleonora Bianchi, Mathilde Bouvier, Gemma Busquet, Paola Caselli, Emmanuel Caux, Steven Charnley, Spandan Choudhury, Nicolas Cuello, Marta De Simone, Francois Dulieu, Aurora Durán, Lucy Evans, Cécile Favre, Davide Fedele, Siyi Feng, Francesco Fontani, Logan Francis, Tetsuya Hama, Tomoyuki Hanawa, Eric Herbst, Shingo Hirano, Tomoya Hirota, Andrea Isella, Izaskun Jímenez-Serra, Doug Johnstone, Claudine Kahane, Romane Le Gal, Laurent Loinard, Ana López-Sepulcre, Luke T. Maud, María José Maureira, Francois Menard, Seyma Mercimek, Anna Miotello, George Moellenbrock, Shoji Mori, Nadia M. Murillo, Riouhei Nakatani, Hideko Nomura, Yasuhiro Oba, Ross O’Donoghue, Satoshi Ohashi, Yuki Okoda, Juan Ospina-Zamudio, Jaime Pineda, Linda Podio, Albert Rimola, Takeshi Sakai, Dominique Segura-Cox, Yancy Shirley, Vianney Taquet, Leonardo Testi, Charlotte Vastel, Naoki Watanabe, Yoshimasa Watanabe, Arezu Witzel, Ci Xue, Bo Zhao, Satoshi Yamamoto, Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), Academia Sinica, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), 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)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -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)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), Department of Astronomy [Tokyo], The University of Tokyo (UTokyo), Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, Università degli Studi di Perugia = University of Perugia (UNIPG), Max-Planck-Institut für Extraterrestrische Physik (MPE), Centre National d'Études Spatiales [Toulouse] (CNES), Institut de recherche en astrophysique et planétologie (IRAP), 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), Japan Science and Technology Agency, European Research Council, European Commission, Agencia Estatal de Investigación (España), National Science Foundation (US), Ministerio de Ciencia, Innovación y Universidades (España), and Ministry of Education, Culture, Sports, Science and Technology (Japan)

Subjects
[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Star Formation, Circumstellar Disks, Interstellar Molecules, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

Imai et al., The chemical diversity of low-mass protostellar sources has so far been recognized, and environmental effects are invoked as its origin. In this context, observations of isolated protostellar sources without the influence of nearby objects are of particular importance. Here, we report the chemical and physical structures of the low-mass Class 0 protostellar source IRAS 16544−1604 in the Bok globule CB 68, based on 1.3 mm Atacama Large Millimeter/submillimeter Array observations at a spatial resolution of ∼70 au that were conducted as part of the large program FAUST. Three interstellar saturated complex organic molecules (iCOMs), CH3OH, HCOOCH3, and CH3OCH3, are detected toward the protostar. The rotation temperature and the emitting region size for CH3OH are derived to be 131 ± 11 K and ∼10 au, respectively. The detection of iCOMs in close proximity to the protostar indicates that CB 68 harbors a hot corino. The kinematic structure of the C18O, CH3OH, and OCS lines is explained by an infalling–rotating envelope model, and the protostellar mass and the radius of the centrifugal barrier are estimated to be 0.08–0.30 M⊙ and, This paper makes use of the following ALMA data: ADS/JAO.ALMA#2016.1.01376.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), NSC and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. The authors acknowledge financial support from JSPS and MAEE under the Japan–France Integrated Action Program (SAKURA: 25765VC). D.J. is supported by NRC Canada and by an NSERC Discovery Grant. E.B. and G.B. acknowledge funding from the European Research Council under the European Union's Horizon 2020 research and innovation program, for the project "The Dawn of Organic Chemistry," grant agreement No. 741002. G.B. acknowledges support from the PID2020-117710GB-I00 grant funded by MCIN/AEI/10.13039/501100011033 and from the Unit of Excellence María de Maeztu 2020–2023 award to the Institute of Cosmos Sciences (CEX2019-00918-M). I.J.-S. has received partial support from the Spanish State Research Agency (AEI) through project Nos. PID2019-105552RB-C41 and MDM-2017-0737 Unidad de Excelencia "Maria de Maeztu" - Centro de Astrobiologia (CSIC-INTA). This study is supported by grants-in-aid from the Ministry of Education, Culture, Sports, Science, and Technology of Japan (18H05222, 18J11010, 19H05069, 19K14753, and 21K13954).

Published
2022
Full Text
View/download PDF

6. FAUST II. Discovery of a Secondary Outflow in IRAS 15398-3359: Variability in Outflow Direction during the Earliest Stage of Star Formation?

Author

Cécile Favre, Serena Viti, Luke T. Maud, Davide Fedele, S. Mercimek, Anna Miotello, Naoki Watanabe, Spandan Choudhury, Siyi Feng, Charlotte Vastel, Ross O'Donoghue, Brian Svoboda, Ci Xue, Claudine Kahane, Yuki Okoda, Doug Johnstone, Yoshimasa Watanabe, Andrea Isella, C. Codella, Yoko Oya, Linda Podio, Nami Sakai, J. Ospina-Zamudio, G. A. Moellenbrock, Aurora Durán, Yancy L. Shirley, Jaime E. Pineda, Paola Caselli, Yasuhiro Oba, François Dulieu, Laurent Loinard, Leonardo Testi, Muneaki Imai, Takeshi Sakai, Arezu Witzel, María José Maureira, Tomoyuki Hanawa, Francesco Fontani, Izaskun Jiménez-Serra, Lucy Evans, Marta De Simone, Felipe O. Alves, Logan Francis, Vianney Taquet, Dominique Segura-Cox, Emmanuel Caux, Mathilde Bouvier, Riouhei Nakatani, Bertrand Lefloch, Yichen Zhang, Nadia Balucani, Cecilia Ceccarelli, Tetsuya Hama, Satoshi Yamamoto, H. Nomura, Claire J. Chandler, Albert Rimola, Bo Zhao, Shoji Mori, Shu-ichiro Inutsuka, Tomoya Hirota, Satoshi Ohashi, Nadia M. Murillo, Eric Herbst, Steven B. Charnley, E. Bianchi, Ana López-Sepulcre, Yuri Aikawa, Francois Menard, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Okoda, Y. [0000-0003-3655-5270], Oya, Y. [0000-0002-0197-8751], Francis, L. [0000-0001-8822-6327], Johnstone, D. [0000-0002-6773-459X], Inutsuka, S. I. [0000-0003-4366-6518], Ceccarelli, C. [0000-0001-9664-6292], Codella, C. [0000-0003-1514-3074], Chandler, C. [0000-0002-7570-5596], Sakai, N. [0000-0002-3297-4497], Aikawa, Y. [0000-0003-3283-6884], Alves, F. [0000-0002-7945-064X], Balucani, N. [0000-0001-5121-5683], Bianchi, E. [0000-0001-9249-7082], Bouvier, M. [0000-0003-0167-0746], Caselli, P. [0000-0003-1481-7911], De Simone, M. [0000-0001-5659-0140], Feng, S. [0000-0002-4707-8409], Fontani, F. [0000-0003-0348-3418], Hama, T. [0000-0002-4991-4044], Hanawa, T. [0000-0002-7538-581X], Herbst, E. [0000-0002-4649-2536], Hirota, T. [0000-0003-1659-095X], Imai, M. [0000-0002-5342-6262], Isella, A. [0000-0001-8061-2207], Jiménez Serra, I. [0000-0003-4493-8714], Kahane, C. [0000-0003-1691-4686], Loinard, L. [0000-0002-5635-3345], López Sepulcre, A. [0000-0002-6729-3640], Maud, L. T. [0000-0002-7675-3565], Maureira, M. J. [0000-0002-7026-8163], Menard, F. [0000-0002-1637-7393], Miotello, A. [0000-0002-7997-2528], Moellenbrock, G. [0000-0002-3296-8134], Oba, Y. [0000-0002-6852-3604], Ohashi, S. [0000-0002-9661-7958], Pineda, J. E. [0000-0002-3972-1978], Rimola, A. [0000-0002-9637-4554], Sakai, T. [0000-0003-4521-7492], Segura Cox, D. [0000-0003-3172-6763], Svoboda, B. [0000-0002-8502-6431], Taquet, V. [0000-0003-0407-7489], European Research Council (ERC), Agencia Estatal de Investigación (AEI), and Japan Society for the Promotion of Science (JSPS)

Subjects
Astrochemistry, FOS: Physical sciences, Astrophysics, 01 natural sciences, 7. Clean energy, Submillimeter Array, Stellar jets, Interstellar medium, 0103 physical sciences, Protostar, 010303 astronomy & astrophysics, Shocks, Solar and Stellar Astrophysics (astro-ph.SR), Line (formation), Astrochimica, Physics, [PHYS]Physics [physics], Accretion (meteorology), 010308 nuclear & particles physics, Star formation, Astronomy and Astrophysics, Interstellar molecules, Astrophysics - Astrophysics of Galaxies, Young stellar objects, Protostars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Outflow, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

We have observed the very low-mass Class 0 protostar IRAS 15398−3359 at scales ranging from 50 to 1800 au, as part of the Atacama Large Millimeter/Submillimeter Array Large Program FAUST. We uncover a linear feature, visible in H2CO, SO, and C18O line emission, which extends from the source in a direction almost perpendicular to the known active outflow. Molecular line emission from H2CO, SO, SiO, and CH3OH further reveals an arc-like structure connected to the outer end of the linear feature and separated from the protostar, IRAS 15398−3359, by 1200 au. The arc-like structure is blueshifted with respect to the systemic velocity. A velocity gradient of 1.2 km s−1 over 1200 au along the linear feature seen in the H2CO emission connects the protostar and the arc-like structure kinematically. SO, SiO, and CH3OH are known to trace shocks, and we interpret the arc-like structure as a relic shock region produced by an outflow previously launched by IRAS 15398−3359. The velocity gradient along the linear structure can be explained as relic outflow motion. The origins of the newly observed arc-like structure and extended linear feature are discussed in relation to turbulent motions within the protostellar core and episodic accretion events during the earliest stage of protostellar evolution. The authors thank the anonymous reviewer for invaluable comments. They are also grateful to Hauyu Baobab Liu for useful discussions. This paper makes use of the following ALMA data set: ADS/JAO.ALMA#2018.1.01205.L (PI: Satoshi Yamamoto). ALMA is a partnership of the ESO (representing its member states), the NSF (USA) and NINS (Japan), together with the NRC (Canada) and the NSC and ASIAA (Taiwan), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by the ESO, the AUI/NRAO, and the NAOJ. The authors thank to the ALMA staff for their excellent support. This work is supported by the projects PRIN-INAF-MAIN-STREAM 2017 Protoplanetary disks seen through the eyes of new-generation instruments, ARIEL and the astrochemical link between circumstellar disks and planets, and the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programmes: The Dawn of Organic Chemistry (DOC), grant agreement No. 741002, and Astro-Chemistry Origins (ACO), grant No. 811312. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. I.J.-S. has received partial support from the Spanish FEDER (project number ESP2017-86582-C4-1-R) and the State Research Agency (AEI; project number PID2019-105552RB-C41). D.J. is supported by NRC Canada and by an NSERC Discovery Grant. This project is also supported by a Grant-in-Aid from Japan Society for the Promotion of Science (KAKENHI: Nos. 18H05222, 19H05069, 19K14753). Yuki Okoda thanks the Advanced Leading Graduate Course for Photon Science (ALPS) and Japan Society for the Promotion of Science (JSPS) for financial support. Peerreview

Published
2021
Full Text
View/download PDF

7. FAUST I. The hot corino at the heart of the prototypical Class I protostar L1551 IRS5

Author

Nadia Balucani, Tetsuya Hama, Bo Zhao, C. Favre, Yancy L. Shirley, Brian Svoboda, H. Nomura, Francois Menard, Yasuhiro Oba, G. Moellenbrock, Laurent Loinard, Charlotte Vastel, M. Bouvier, Shoji Mori, Andrea Isella, François Dulieu, Leonardo Testi, S. Yamamoto, E. Bianchi, Spandan Choudhury, Nami Sakai, M. De Simone, Aurora Durán, Linda Podio, Luke T. Maud, S. Mercimek, Jaime E. Pineda, D. Johnstone, Y. Oya, D. Segura Cox, P. Caselli, Ana López-Sepulcre, Claudine Kahane, Y. Aikawa, Bertrand Lefloch, M. J. Maureira, L. Evans, C. Codella, I. Jimenez-Serra, M. Imai, Naoki Watanabe, Francesco Fontani, S. Ohashi, Siyi Feng, Felipe O. Alves, Anna Miotello, Claire J. Chandler, Logan Francis, Ci Xue, Emmanuel Caux, Andrea Lusvarghi Witzel, Eric Herbst, Albert Rimola, Vianney Taquet, Steven B. Charnley, Cecilia Ceccarelli, Yoshimasa Watanabe, Y. Zhang, Davide Fedele, R. Nakatani, J. Ospina-Zamudio, Y. Okoda, Tomoya Hirota, Takeshi Sakai, S. Viti, Tomoyuki Hanawa, Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737, Balucani, N. [0000-0001-5121-5683], De Oliveira Alves, F. [0000-0002-7945-064X], Hama, T. [0000-0002-4991-4044], Ohashi, S. [0000-0002-9661-7958], Johnstone, D. [0000-0002-6773-459X], Watanabe, Y. [0000-0002-9668-3592], Ceccarelli, C. [0000-0001-9664-6292], Pineda, J. [0000-0002-3972-1978], Fedele, D. [0000-0001-6156-0034], Mercimek, S. [0000-0002-0742-7934], Xue, C. [0000-0003-2760-2119], Sakai, N. [0000-0002-3297-4497], European Research Council (ERC), Japan Society for the Promotion of Science (KAKENHI), Agencia Estatal de Investigación (AEI), Universidad Nacional Autónoma de México (UNAM), Agence Nationale de la Recherche (ANR), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), 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)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-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)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Department of Materials Science and Engineering, Shibaura Institute of Technology, Japan Society for the Promotion of Science (KAKENHI), 18H05222 19H05069 19K14753, Ministerio de Economía y Competitividad (MINECO), Universidad Nacional Autónoma de México (UNAM) IN112417 IN112820, and French National Research Agency (ANR), ANR-16-CE31-0013 ANR-15-IDEX-02

Subjects
Astrochemistry, 010504 meteorology & atmospheric sciences, Methyl formate, FOS: Physical sciences, Astrophysics, 01 natural sciences, chemistry.chemical_compound, Planet, Phase (matter), 0103 physical sciences, Protostar, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), formation [Stars], molecules [ISM], 0105 earth and related environmental sciences, Physics, Astrochimica, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy and Astrophysics, Radius, Planetary system, Astrophysics - Astrophysics of Galaxies, chemistry, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics of Galaxies (astro-ph.GA), Methanol, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA]
Abstract

Bianchi, E. et al., The study of hot corinos in solar-like protostars has been so far mostly limited to the Class 0 phase, hampering our understanding of their origin and evolution. In addition, recent evidence suggests that planet formation starts already during Class I phase, which therefore represents a crucial step in the future planetary system chemical composition. Hence, the study of hot corinos in Class I protostars has become of paramount importance. Here, we report the discovery of a hot corino towards the prototypical Class I protostar L1551 IRS5, obtained within the ALMA (Atacama Large Millimeter/submillimeter Array) Large Program FAUST (Fifty AU STudy of the chemistry in the disc/envelope system of solar-like protostars).We detected several lines from methanol and its isotopologues (13CH3OH and CH2DOH), methyl formate, and ethanol. Lines are bright towards the north component of the IRS5 binary system, and a possible second hot corino may be associated with the south component. The methanol lines' non-LTE analysis constrains the gas temperature (100 K), density (1.5 × 108 cm3), and emitting size (10 au in radius). All CH3OH and 13CH3OH lines are optically thick, preventing a reliable measure of the deuteration. The methyl formate and ethanol relative abundances are compatible with those measured in Class 0 hot corinos. Thus, based on this work, little chemical evolution from Class 0 to I hot corinos occurs., With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737)

Published
2020
Full Text
View/download PDF

8. Thermal balance and comparison of gas and dust properties of dense clumps in the Hi-GAL survey

Author

Neal J. Evans, Davide Elia, Alessio Traficante, Eugenio Schisano, Brian Svoboda, Kazi L.J. Rygl, Manuel Merello, Sergio Molinari, Paul F. Goldsmith, and Yancy L. Shirley

Subjects
Physics, 010308 nuclear & particles physics, Foundation (engineering), Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, media_common.cataloged_instance, Astrophysics::Solar and Stellar Astrophysics, European union, 010303 astronomy & astrophysics, Thermal balance, Astrophysics::Galaxy Astrophysics, media_common
Abstract

We present a comparative study of physical properties derived from gas and dust emission in a sample of 1068 dense Galactic clumps. The sources are selected from the crossmatch of the Hi-GAL survey with 16 catalogues of NH$_3$ line emission in its lowest inversion (1,1) and (2,2) transitions. The sample covers a large range in masses and bolometric luminosities, with surface densities above $\Sigma=0.1$ g cm$^{-2}$ and with low virial parameters $\alpha, Comment: 28 pages, 22 figures, accepted for publication in MNRAS

Published
2018

9. Searching for Inflow Towards Massive Starless Clump Candidates Identified in the Bolocam Galactic Plane Survey

Author

Jenny K. Calahan, Anna Pulley, Marina Dunn, Carter Bosse, Laurin Gray, Quadry Chance, Yancy L. Shirley, Qasim Mahmood, Ian Kearsley, Adriana M. Mitchell, Scott McKinley, C. W. Cook, Sarah Choi, Christopher Bullivant, Nicole Zawadzki, Ramon Jaime-Frias, Joseph Kelledy, Jonathan R. Schmid, Collin Lewin, Andrew Henrici, Daniel R. Robinson, Massimo Pascale, Jennifer Lautenbach, Brian Svoboda, and Elizabeth A. Ivanov

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Population, FOS: Physical sciences, Astrophysics, Inflow, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, law.invention, Telescope, Atmospheric radiative transfer codes, Radio observatory, law, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, education, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics, education.field_of_study, 010308 nuclear & particles physics, Star formation, Astronomy and Astrophysics, Galactic plane, Astrophysics - Astrophysics of Galaxies, Galaxy, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA)
Abstract

Recent Galactic plane surveys of dust continuum emission at long wavelengths have identified a population of dense, massive clumps with no evidence for on-going star formation. These massive starless clump candidates are excellent sites to search for the initial phases of massive star formation before the feedback from massive star formation effects the clump. In this study, we search for the spectroscopic signature of inflowing gas toward starless clumps, some of which are massive enough to form a massive star. We observed 101 starless clump candidates identified in the Bolocam Galactic Plane Survey (BGPS) in HCO+ J = 1-0 using the 12m Arizona Radio Observatory telescope. We find a small blue excess of E = (Nblue - Nred)/Ntotal = 0.03 for the complete survey. We identified 6 clumps that are good candidates for inflow motion and used a radiative transfer model to calculate mass inflow rates that range from 500 - 2000 M /Myr. If the observed line profiles are indeed due to large-scale inflow motions, then these clumps will typically double their mass on a free fall time. Our survey finds that massive BGPS starless clump candidates with inflow signatures in HCO+ J = 1-0 are rare throughout our Galaxy., 14 pages, 9 figures

Published
2018

10. The Bolocam Galactic Plane Survey. X. A Complete Spectroscopic Catalog of Dense Molecular Gas Observed toward 1.1 mm Dust Continuum Sources with 7.5 <= l <= 194 degrees

Author

Adam Ginsburg, Guy S. Stringfellow, Erik Rosolowsky, Jason Glenn, S. Mairs, Thomas Gerner, Cara Battersby, Wayne Schlingman, Brian Svoboda, John Bally, Yancy L. Shirley, M. K. Dunham, and Timothy P. Ellsworth-Bowers

Subjects
Physics, Mean kinetic temperature, Milky Way, Flux, Astronomy and Astrophysics, Astrophysics, Galactic plane, Astrophysics - Astrophysics of Galaxies, Galaxy, law.invention, Telescope, Stars, Space and Planetary Science, law, Excitation
Abstract

The Bolocam Galactic Plane Survey (BGPS) is a 1.1 mm continuum survey of dense clumps of dust throughout the Galaxy covering 170 square degrees. We present spectroscopic observations using the Heinrich Hertz Submillimeter Telescope of the dense gas tracers, HCO+ and N2H+ 3-2, for all 6194 sources in the Bolocam Galactic Plane Survey v1.0.1 catalog between 7.5 0.5 K) without HCO+ 3-2 emission does not occur in this catalog. We characterize the properties of the dense molecular gas emission toward the entire sample. HCO+ is very sub-thermally populated and the 3-2 transitions are optically thick toward most BGPS clumps. The median observed line width is 3.3 km/s consistent with supersonic turbulence within BGPS clumps. We find strong correlations between dense molecular gas integrated intensities and 1.1 mm peak flux and the gas kinetic temperature derived from previously published NH3 observations. These intensity correlations are driven by the sensitivity of the 3-2 transitions to excitation conditions rather than by variations in molecular column density or abundance. We identify a subset of 113 sources with stronger N2H+ than HCO+ integrated intensity, but we find no correlations between the N2H+ / HCO+ ratio and 1.1 mm continuum flux density, gas kinetic temperature, or line width. Self-absorbed profiles are rare (1.3%)., Comment: Accepted for publication in ApJS. The full velocity catalog and data tables (complete Tables 2,3, and 5) may be downloaded from http://eldora.as.arizona.edu/~yshirley/Arizona/BGPS/ Kinematic finder charts (0.5 deg x 0.5 deg) are also available at the same address

Published
2013

11. Misaligned Rotations of the Envelope, Outflow, and Disks in the Multiple Protostellar System of VLA 1623–2417: FAUST. III

Author

Satoshi Ohashi, Claudio Codella, Nami Sakai, Claire J. Chandler, Cecilia Ceccarelli, Felipe Alves, Davide Fedele, Tomoyuki Hanawa, Aurora Durán, Cécile Favre, Ana López-Sepulcre, Laurent Loinard, Seyma Mercimek, Nadia M. Murillo, Linda Podio, Yichen Zhang, Yuri Aikawa, Nadia Balucani, Eleonora Bianchi, Mathilde Bouvier, Gemma Busquet, Paola Caselli, Emmanuel Caux, Steven Charnley, Spandan Choudhury, Nicolas Cuello, Marta De Simone, Francois Dulieu, Lucy Evans, Siyi Feng, Francesco Fontani, Logan Francis, Tetsuya Hama, Eric Herbst, Shingo Hirano, Tomoya Hirota, Muneaki Imai, Andrea Isella, Izaskun Jímenez-Serra, Doug Johnstone, Claudine Kahane, Romane Le Gal, Bertrand Lefloch, Luke T. Maud, Maria Jose Maureira, Francois Menard, Anna Miotello, George Moellenbrock, Shoji Mori, Riouhei Nakatani, Hideko Nomura, Yasuhiro Oba, Ross O’Donoghue, Yuki Okoda, Juan Ospina-Zamudio, Yoko Oya, Jaime Pineda, Albert Rimola, Takeshi Sakai, Dominique Segura-Cox, Yancy Shirley, Brian Svoboda, Vianney Taquet, Leonardo Testi, Charlotte Vastel, Serena Viti, Naoki Watanabe, Yoshimasa Watanabe, Arezu Witzel, Ci Xue, Bo Zhao, Satoshi Yamamoto, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), 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)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -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)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Institut de recherche en astrophysique et planétologie (IRAP), 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), and 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)

Subjects
[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Star formation, Astronomy and Astrophysics, Interstellar matter, Astrophysics::Cosmology and Extragalactic Astrophysics, Interstellar molecules, Molecules, Formació d'estels, Young stellar objects, Protostars, Stellar jets, Space and Planetary Science, Circumstellar disks, Interstellar medium, [SDU]Sciences of the Universe [physics], Astrophysics::Solar and Stellar Astrophysics, Matèria interstel·lar, Astrophysics::Earth and Planetary Astrophysics, Molècules, Astrophysics::Galaxy Astrophysics, Astrochemistry
Abstract

We report a study of the low-mass Class 0 multiple system VLA 1623AB in the Ophiuchus star-forming region, using H13CO+ (J = 3–2), CS (J = 5–4), and CCH (N = 3–2) lines as part of the ALMA Large Program FAUST. The analysis of the velocity fields revealed the rotation motion in the envelope and the velocity gradients in the outflows (about 2000 au down to 50 au). We further investigated the rotation of the circumbinary VLA 1623A disk, as well as the VLA 1623B disk. We found that the minor axis of the circumbinary disk of VLA 1623A is misaligned by about 12° with respect to the large-scale outflow and the rotation axis of the envelope. In contrast, the minor axis of the circumbinary disk is parallel to the large-scale magnetic field according to previous dust polarization observations, suggesting that the misalignment may be caused by the different directions of the envelope rotation and the magnetic field. If the velocity gradient of the outflow is caused by rotation, the outflow has a constant angular momentum and the launching radius is estimated to be 5–16 au, although it cannot be ruled out that the velocity gradient is driven by entrainments of the two high-velocity outflows. Furthermore, we detected for the first time a velocity gradient associated with rotation toward the VLA 16293B disk. The velocity gradient is opposite to the one from the large-scale envelope, outflow, and circumbinary disk. The origin of its opposite gradient is also discussed.

Full Text
View/download PDF

12. The Lifetimes of Phases in High-mass Star-forming Regions.

Author

Cara Battersby, John Bally, and Brian Svoboda

Subjects
STAR clusters, STAR formation, COSMIC dust, MOLECULAR clouds, KINEMATICS
Abstract

High-mass stars form within star clusters from dense, molecular regions (DMRs), but is the process of cluster formation slow and hydrostatic or quick and dynamic? We link the physical properties of high-mass star-forming regions with their evolutionary stage in a systematic way, using Herschel and Spitzer data. In order to produce a robust estimate of the relative lifetimes of these regions, we compare the fraction of DMRs above a column density associated with high-mass star formation, N(H2) > 0.4–2.5 × 1022 cm−2, in the “starless” (no signature of stars ≳10 forming) and star-forming phases in a 2° × 2° region of the Galactic Plane centered at ℓ = 30°. Of regions capable of forming high-mass stars on ∼1 pc scales, the starless (or embedded beyond detection) phase occupies about 60%–70% of the DMR lifetime, and the star-forming phase occupies about 30%–40%. These relative lifetimes are robust over a wide range of thresholds. We outline a method by which relative lifetimes can be anchored to absolute lifetimes from large-scale surveys of methanol masers and UCHII regions. A simplistic application of this method estimates the absolute lifetime of the starless phase to be 0.2–1.7 Myr (about 0.6–4.1 fiducial cloud free-fall times) and the star-forming phase to be 0.1–0.7 Myr (about 0.4–2.4 free-fall times), but these are highly uncertain. This work uniquely investigates the star-forming nature of high column density gas pixel by pixel, and our results demonstrate that the majority of high column density gas is in a starless or embedded phase. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results