Search

We present the first results from the science demonstration phase for the Hi-GAL survey, the Herschel key program that will map the inner Galactic plane of the Milky Way in 5 bands. We outline our data reduction strategy and present some science highlights on the two observed 2° × 2° tiles approximately centered at l = 30° and l = 59°. The two regions are extremely rich in intense and highly structured extended emission which shows a widespread organization in filaments. Source SEDs can be built for hundreds of objects in the two fields, and physical parameters can be extracted, for a good fraction of them where the distance could be estimated. The compact sources (which we will call cores' in the following) are found for the most part to be associated with the filaments, and the relationship to the local beam-averaged column density of the filament itself shows that a core seems to appear when a threshold around AV ~ 1 is exceeded for the regions in the l = 59° field; a AV value between 5 and 10 is found for the l = 30° field, likely due to the relatively higher distances of the sources. This outlines an exciting scenario where diffuse clouds first collapse into filaments, which later fragment to cores where the column density has reached a critical level. In spite of core L/M ratios being well in excess of a few for many sources, we find core surface densities between 0.03 and 0.5 g cm-2. Our results are in good agreement with recent MHD numerical simulations of filaments forming from large-scale converging flows.

New observations with Herschel allow accurate measurement of the equilibrium temperature of large dust grains heated by the interstellar radiation field (ISRF), which is critical in deriving dust column density and masses. We present temperature maps derived from the Herschel SPIRE and PACS data in two fields along the Galactic plane, obtained as part of the Hi-GAL survey during the Herschel science demonstration phase (SDP). We analyze the distribution of the dust temperature spatially, as well as along the two lines-of-sight (LOS) through the Galaxy. The zero-level offsets in the Herschel maps were established by comparison with the IRAS and Planck data at comparable wavelengths. We derive maps of the dust temperature and optical depth by adjusting a detailed model for dust emission at each pixel. The dust temperature maps show variations in the ISRF intensity and reveal the intricate mixture of the warm dust heated by massive stars and the cold filamentary structures of embedded molecular clouds. The dust optical depth at 250 μm is well correlated with the gas column density, but with a significantly higher dust emissivity than in the solar neighborhood. We correlate the optical depth with 3-D cubes of the dust extinction to investigate variations in the ISRF strength and dust abundance along the line of sight through the spiral structure of the Galaxy. We show that the warmest dust along the LOS is located in the spiral arms of the Galaxy, and we quantify their respective IR contribution.

We present here 350 and 500 micron polarization observations of the Lupus I molecular cloud taken during the 2010 BLASTPol Antarctic flight. Lupus I is a nearby, isolated, young, and filamentary molecular cloud making it an ideal target to test magnetically regulated star formation models. In the presence of intermediate to strong magnetic fields (in comparison to turbulence), these models predict the formation of large filaments extended perpendicular to the local magnetic field direction as gas preferentially collapses along the field lines. We compare the BLASTPol polarization observations with previous optical polarimetry and find a uniform large-scale field direction from low to high density in Lupus I, consistent with magnetically regulated star formation models.

The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) is a suborbital surveying experiment designed to study the evolutionary history and processes of star formation in local galaxies (including the Milky Way) and galaxies at cosmological distances. The BLAST continuum camera, which consists of 270 detectors distributed between three arrays, observes simultaneously in broadband (30%) spectral windows at 250, 350, and 500 microns. The optical design is based on a 2 m diameter telescope, providing a diffraction-limited resolution of 30" at 250 microns. The gondola pointing system enables raster mapping of arbitrary geometry, with a repeatable positional accuracy of 30"; postflight pointing reconstruction to <5" rms is achieved. The onboard telescope control software permits autonomous execution of a preselected set of maps, with the option of manual override. On this poster, we describe the primary characteristics and measured in-flight performance of BLAST. BLAST performed a test flight in 2003 and has since made two scientifically productive long-duration balloon flights: a 100 hour flight from ESRANGE (Kiruna), Sweden to Victoria Island, northern Canada in 2005 June; and a 250 hour, circumpolar flight from McMurdo Station, Antarctica in 2006 December. The BLAST collaboration acknowledges the support of NASA through grants NAG5-12785, NAG5-13301, and NNGO-6GI11G, the Canadian Space Agency (CSA), the Science and Technology Facilities Council (STFC), Canada's Natural Sciences and Engineering Research Council (NSERC), the Canada Foundation for Innovation, the Ontario Innovation Trust, the Puerto Rico Space Grant Consortium, the Fondo Institucional para la Investigacion of the University of Puerto Rico, and the National Science Foundation Office of Polar Programs.

We present here 350 and 500 micron polarization observations of the Lupus I molecular cloud taken during the 2010 BLASTPol Antarctic flight. Lupus I is a nearby, isolated, young, and filamentary molecular cloud making it an ideal target to test magnetically regulated star formation models. In the presence of intermediate to strong magnetic fields (in comparison to turbulence), these models predict the formation of large filaments extended perpendicular to the local magnetic field direction as gas preferentially collapses along the field lines. We compare the BLASTPol polarization observations with previous optical polarimetry and find a uniform large-scale field direction from low to high density in Lupus I, consistent with magnetically regulated star formation models.

We present the first results from the science demonstration phase for the Hi-GAL survey, the Herschel key program that will map the inner Galactic plane of the Milky Way in 5 bands. We outline our data reduction strategy and present some science highlights on the two observed 2° × 2° tiles approximately centered at l = 30° and l = 59°. The two regions are extremely rich in intense and highly structured extended emission which shows a widespread organization in filaments. Source SEDs can be built for hundreds of objects in the two fields, and physical parameters can be extracted, for a good fraction of them where the distance could be estimated. The compact sources (which we will call cores' in the following) are found for the most part to be associated with the filaments, and the relationship to the local beam-averaged column density of the filament itself shows that a core seems to appear when a threshold around AV ~ 1 is exceeded for the regions in the l = 59° field; a AV value between 5 and 10 is found for the l = 30° field, likely due to the relatively higher distances of the sources. This outlines an exciting scenario where diffuse clouds first collapse into filaments, which later fragment to cores where the column density has reached a critical level. In spite of core L/M ratios being well in excess of a few for many sources, we find core surface densities between 0.03 and 0.5 g cm-2. Our results are in good agreement with recent MHD numerical simulations of filaments forming from large-scale converging flows.

New observations with Herschel allow accurate measurement of the equilibrium temperature of large dust grains heated by the interstellar radiation field (ISRF), which is critical in deriving dust column density and masses. We present temperature maps derived from the Herschel SPIRE and PACS data in two fields along the Galactic plane, obtained as part of the Hi-GAL survey during the Herschel science demonstration phase (SDP). We analyze the distribution of the dust temperature spatially, as well as along the two lines-of-sight (LOS) through the Galaxy. The zero-level offsets in the Herschel maps were established by comparison with the IRAS and Planck data at comparable wavelengths. We derive maps of the dust temperature and optical depth by adjusting a detailed model for dust emission at each pixel. The dust temperature maps show variations in the ISRF intensity and reveal the intricate mixture of the warm dust heated by massive stars and the cold filamentary structures of embedded molecular clouds. The dust optical depth at 250 μm is well correlated with the gas column density, but with a significantly higher dust emissivity than in the solar neighborhood. We correlate the optical depth with 3-D cubes of the dust extinction to investigate variations in the ISRF strength and dust abundance along the line of sight through the spiral structure of the Galaxy. We show that the warmest dust along the LOS is located in the spiral arms of the Galaxy, and we quantify their respective IR contribution.

The "Large Millimeter Telescope" (LMT) is a joint U.S.A. and Mexico Project and will be the world's largest millimeter-wavelength radio telescope, equipped with the state-of-the-art heterodyne and bolometric focal plane arrays. We show that CO lines (and also CS) will be able to be detected in unlensed galaxies. Furthermore, the continuum camera will allow measurements of the Sunyaev-Zel'dovich effect, as well as enabling deep surveys of dust emission from protogalaxies.

BLAST the Balloon-borne Large Aperture Sub-millimeter Telescope, will have three bolometer arrays operating at 250, 350, and 500 pm, with 149, 88, and 43 detectoi-s respectively. The arrays will be cooled to 300 rnK so that the receiver's noise (NEFD) will be dominated by photon shot noise and atmospheric emission. Because of the high (35 km) altitude of balloon observations, atmospheric noise will be low and we expect NEFDs less than 241 mJy/H:1 2 in all channels. A 2.0 m diameter spherical mirror will give diffraction limited resolutions of 30, 41, and 59" respectively. The first test flight, planned for early 2003, will last 6-24 hours across North America. Long-duration balloon flights from Antarctica will begin in late 2003 and will last 14 days. BLAST will yield data on astronomical problems as close as nearby stars and as far away as the beginnings of the Universe.

The Balloon-borne Large-Aperture Sub-millimetre Telescope (BLAST) will operate on a Long Duration Balloon platform with large format bolometer arrays at 250, 350 and 500 microns, initially using a 2.0 m mirror, with plans to increase to 2.5 m. BLAST is a collaboration between scientists in the USA, Canada, UK, Italy and Mexico. Funding has been approved and it is now in its building phase. The test flight is scheduled for 2002, with the first long duration flight the following year. The scientific goals are to learn about the nature of distant extragalactic star forming galaxies and cold pre-stellar sources by making deep maps both at high and low galactic latitudes. BLAST will be useful for planning Herschel key projects which use SPIRE.

BLAST-pol (Balloon-borne Large Aperture Submillimeter Telescope for Polarimetery) combines a 1.9 meter Cassegrain telescope and a submillimeter polarimeter that operates in three bands (250, 350, and 500 microns), each with 30% bandwidth. The detection system is comprised of 270 silicon-nitride micromesh bolometers distributed on three focal plane arrays with 30", 42", and 60" FWHM beam sizes, respectively. The detectors are a prototype for the SPIRE instrument used on Herschel. Polarization sensitivity is achieved by placing polarized grids on the bolometer arrays and with a rotatable Achromatic Half Wave Plate (AHWP) located in front of the arrays. The instrument operates on a balloon at an altitude of ~40km due to the high opacity of the earth’s sea level atmosphere at submillimeter wavelengths. The main scientific objective of BLAST-pol is to determine what role magnetic fields play in star formation. This is achieved by making large, high resolution, linear polarization maps of giant molecular clouds (GMCs), and their substructures. These maps can then be compared to maps created using numerical turbulence simulations to ascertain how magnetic fields affect the morphology and lifetime of these structures. The non-polarized version of BLAST has had two scientific flights and is scheduled to fly again as BLAST-pol in December 2010 from McMurdo, Antarctica.

BLAST (The Balloon-borne Large Aperture Submillimeter Telescope) is a 1.9 meter telescope, that feeds a focal plane of 266 feedhorn-coupled bolometers at 250, 350 and 500 microns, with diffraction limited beam FWHM of 30 arcseconds at 250 microns. The experiment has been successfully flown from Sweden in 2005 and from Antarctica in 2006, as described in the poster by M. Truch and collaborators at this meeting. In this poster, we describe the upgrade that will add polarimetric capability to all three wavebands, thereby converting BLAST into BLAST-pol. Polarizing grids will be mounted in front of each of our detector arrays, and a 4 K rotating achromatic half-wave plate will be installed in the optical path, upstream from the cold pupil. BLAST-pol's primary science goal is to create deep, sensitive, large area maps of polarized dust emission in Galactic star forming clouds. For dozens of giant molecular clouds, we will produce three-color polarization maps covering the entire extent of each cloud, with sufficient resolution to probe into the dense cores. These data will provide an unprecedented view of the clouds' magnetic morphologies, the degree of order in the magnetic field, and the relationship to the filamentary structure that is commonly seen in these clouds. BLAST-pol will also measure high latitude polarized dust emission, the understanding of which is crucial for Cosmic Microwave Background Polarization experiments. BLAST-pol is currently under construction with a first flight planned for December 2009 from Antarctica.

The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) is a suborbital surveying experiment designed to study the evolutionary history and processes of star formation in local galaxies (including the Milky Way) and galaxies at cosmological distances. The BLAST continuum camera, which consists of 270 detectors distributed between three arrays, observes simultaneously in broadband (30%) spectral windows at 250, 350, and 500µm, akin to the SPIRE instrument on Herschel. The optical design is based on a 2m diameter telescope, providing nearly diffraction-limited resolution of 36“ at 250µm. BLAST performed a test flight in 2003 and has since made two scientifically productive long-duration balloon flights: a 100 hour flight from ESRANGE (Kiruna), Sweden to Victoria Island, northern Canada in 2005 June; and a 250 hour, circumpolar flight from McMurdo Station, Antarctica in 2006 December. A deep, confusion limited, 0.8 deg² map nested in a wide, 8.6 deg² map in the direction of GOODS-South was made during the 2006 flight. Approximately half of all the light from stars is absorbed and reprocessed by dust. The resulting emission is grey body with a temperature near 30K. While it is believed that this radiation makes up the Far Infrared Background (FIRB) detected by COBE, it had not been resolved into individual galaxies. Combining BLAST data with data from Spitzer in the same region, we determine that at 500µm all of the FIRB comes from sources that are identified in deep 24µm surveys and that 70% of the FIRB comes from sources with z>1.2. Furthermore, we determine the number of galaxies as a function of flux and frequency in the submillimeter revealing a distinct evolution in the galaxy population from low to high redshift. The BLAST collaboration acknowledges the support of NASA, NSF Office of Polar Programs, the CSA (Canada), the STFC (UK), and NSERC (Canada).

The Balloon-born Large Aperture Submillimeter Telescope (BLAST) is a 1.8 m mirror that uses focal plane arrays of bolometer detectors at 250, 350 and 500 microns to study the evolutionary history and processes associated with star formation. The most recent long duration balloon flight from Antarctica collected 250 hours of data during a circumpolar flight in December 2006. A large number of observations were conducted including deep and wide surveys to characterize submillimeter galaxies, a galactic plane survey in the Vela region, and a number of pointed observations toward nearby galaxies NGC1097, NGC1291, NGC1365, NGC1512, NGC1566, and NGC1808. In this talk we will focus on these galaxies and combine the BLAST data with Spitzer-MIPS data to uniquely determine dust properties such as temperature and emissivity. The BLAST collaboration acknowledges the support of NASA through grants NAG5 12785, NAG5-13301, and NNGO-6GI11G, the Canadian Space Agency (CSA), the Science and Technology Facilities Council (STFC), Canada's Natural Sciences and Engineering Research Council (NSERC), the Canada Foundation for Innovation, the Ontario Innovation Trust, the Puerto Rico Space Grant Consortium, the Fondo Institucional para la Investigacion of the University of Puerto Rico, and the National Science Foundation Office of Polar Programs.

The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) is a suborbital surveying experiment designed to study the evolutionary history and processes of star formation in local galaxies (including the Milky Way) and galaxies at cosmological distances. The BLAST continuum camera, which consists of 270 detectors distributed between three arrays, observes simultaneously in broadband (30%) spectral windows at 250, 350, and 500µm. The optical design is based on a 2m diameter telescope, providing nearly diffraction-limited resolution of 36” at 250µm. BLAST was flown in a test flight in 2003 and has since made two scientifically productive long-duration balloon flights: a 100 hour flight from ESRANGE (Kiruna), Sweden to Victoria Island, northern Canada in 2005 June; and a 250 hour, circumpolar flight from McMurdo Station, Antarctica in 2006 December. A deep, confusion limited, 0.8 deg² map nested in a wide, 8.6 deg² map in the direction of GOODS-South was made during the 2006 flight. Approximately half of all the light from stars is absorbed and reprocessed by dust. The resulting emission is grey body with a temperature near 30K. While it is believed that this radiation makes up the Far Infrared Background (FIRB) detected by the COBE satellite, it had not been resolved into individual galaxies. Combining BLAST data with data from Spitzer in the same region, we determine that at 500µm all of the FIRB comes from sources that are identified in deep 24µm surveys and that 70% of the FIRB comes from sources with z>1.2. Furthermore, we determine the number of galaxies as a function of flux and frequency in the submillimeter revealing a distinct evolution in the galaxy population from low to high redshift. The BLAST collaboration acknowledges the support of NASA, NSF Office of Polar Programs, the CSA (Canada), the STFC (UK), and NSERC (Canada).

The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) is a suborbital surveying experiment designed to study the evolutionary history and processes of star formation in local galaxies (including the Milky Way) and galaxies at cosmological distances. The BLAST continuum camera, which consists of 270 detectors distributed between three arrays, observes simultaneously in broadband (30%) spectral windows at 250, 350, and 500 microns. The optical design is based on a 2 m diameter telescope, providing a diffraction-limited resolution of 30' at 250 microns. The gondola pointing system enables raster mapping of arbitrary geometry, with a repeatable positional accuracy of 30'; postflight pointing reconstruction to <5' rms is achieved. The onboard telescope control software permits autonomous execution of a preselected set of maps, with the option of manual override. On this poster, we describe the primary characteristics and measured in-flight performance of BLAST. BLAST performed a test flight in 2003 and has since made two scientifically productive long-duration balloon flights: a 100 hour flight from ESRANGE (Kiruna), Sweden to Victoria Island, northern Canada in 2005 June; and a 250 hour, circumpolar flight from McMurdo Station, Antarctica in 2006 December. The BLAST collaboration acknowledges the support of NASA through grants NAG5-12785, NAG5-13301, and NNGO-6GI11G, the Canadian Space Agency (CSA), the Science and Technology Facilities Council (STFC), Canada's Natural Sciences and Engineering Research Council (NSERC), the Canada Foundation for Innovation, the Ontario Innovation Trust, the Puerto Rico Space Grant Consortium, the Fondo Institucional para la Investigacion of the University of Puerto Rico, and the National Science Foundation Office of Polar Programs.

From diffuse interstellar cirrus to dense atomic and molecular clouds, from protostellar to post-AGB envelopes, from super-shells to supernovae remnants, the Herschel Hi-GAL survey offer an unprecedented snapshot of all the different phases of the Galactic ISM, its evolution and interactions. I will present early results on a variety of topics including the lifetime of massive pre-stellar phases, the fragmentation and collapse of extended structures, the timeline for massive star formation, dust properties in cirrus and molecular clouds.

The Balloon-borne Large-Aperture Sub-millimetre Telescope (BLAST) will operate on a Long Duration Balloon platform with large format bolometer arrays at 250, 350 and 500 microns, initially using a 2.0 m mirror, with plans to increase to 2.5 m. BLAST is a collaboration between scientists in the USA, Canada, UK, Italy and Mexico. Funding has been approved and it is now in its building phase. The test flight is scheduled for 2002, with the first long duration flight the following year. The scientific goals are to learn about the nature of distant extragalactic star forming galaxies and cold pre-stellar sources by making deep maps both at high and low galactic latitudes. BLAST will be useful for planning Herschel key projects which use SPIRE.

BLAST the Balloon-borne Large Aperture Sub-millimeter Telescope, will have three bolometer arrays operating at 250, 350, and 500 pm, with 149, 88, and 43 detectoi-s respectively. The arrays will be cooled to 300 rnK so that the receiver's noise (NEFD) will be dominated by photon shot noise and atmospheric emission. Because of the high (35 km) altitude of balloon observations, atmospheric noise will be low and we expect NEFDs less than 241 mJy/H:1 2 in all channels. A 2.0 m diameter spherical mirror will give diffraction limited resolutions of 30, 41, and 59" respectively. The first test flight, planned for early 2003, will last 6-24 hours across North America. Long-duration balloon flights from Antarctica will begin in late 2003 and will last 14 days. BLAST will yield data on astronomical problems as close as nearby stars and as far away as the beginnings of the Universe.

BLAST (The Balloon-borne Large Aperture Submillimeter Telescope) is a 1.9 meter telescope, that feeds a focal plane of 266 feedhorn-coupled bolometers at 250, 350 and 500 microns, with diffraction limited beam FWHM of 30 arcseconds at 250 microns. The experiment has been successfully flown from Sweden in 2005 and from Antarctica in 2006, as described in the poster by M. Truch and collaborators at this meeting. In this poster, we describe the upgrade that will add polarimetric capability to all three wavebands, thereby converting BLAST into BLAST-pol. Polarizing grids will be mounted in front of each of our detector arrays, and a 4 K rotating achromatic half-wave plate will be installed in the optical path, upstream from the cold pupil. BLAST-pol's primary science goal is to create deep, sensitive, large area maps of polarized dust emission in Galactic star forming clouds. For dozens of giant molecular clouds, we will produce three-color polarization maps covering the entire extent of each cloud, with sufficient resolution to probe into the dense cores. These data will provide an unprecedented view of the clouds' magnetic morphologies, the degree of order in the magnetic field, and the relationship to the filamentary structure that is commonly seen in these clouds. BLAST-pol will also measure high latitude polarized dust emission, the understanding of which is crucial for Cosmic Microwave Background Polarization experiments. BLAST-pol is currently under construction with a first flight planned for December 2009 from Antarctica.

BLAST-pol (Balloon-borne Large Aperture Submillimeter Telescope for Polarimetery) combines a 1.9 meter Cassegrain telescope and a submillimeter polarimeter that operates in three bands (250, 350, and 500 microns), each with 30% bandwidth. The detection system is comprised of 270 silicon-nitride micromesh bolometers distributed on three focal plane arrays with 30", 42", and 60" FWHM beam sizes, respectively. The detectors are a prototype for the SPIRE instrument used on Herschel. Polarization sensitivity is achieved by placing polarized grids on the bolometer arrays and with a rotatable Achromatic Half Wave Plate (AHWP) located in front of the arrays. The instrument operates on a balloon at an altitude of ~40km due to the high opacity of the earth’s sea level atmosphere at submillimeter wavelengths. The main scientific objective of BLAST-pol is to determine what role magnetic fields play in star formation. This is achieved by making large, high resolution, linear polarization maps of giant molecular clouds (GMCs), and their substructures. These maps can then be compared to maps created using numerical turbulence simulations to ascertain how magnetic fields affect the morphology and lifetime of these structures. The non-polarized version of BLAST has had two scientific flights and is scheduled to fly again as BLAST-pol in December 2010 from McMurdo, Antarctica.