* Astronomy

BLAST is now floating and spinning its way up into the stratosphere.
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Balloon-Borne Large-Aperture Telescope Launched From Antarctica

A giant helium balloon is slowly drifting above Antarctica, about 36 kilometres up. Launched on Tuesday (Dec. 25) from the National Science Foundation's Long Duration Balloon (LDB) facility on Earth's southernmost continent, it carries a sensitive telescope that measures submillimetre light waves from stellar nurseries in our Milky Way.
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Title: The Balloon-Borne Large Aperture Submillimeter Telescope (BLAST) 2005: A 10 deg² Survey of Star Formation in Cygnus X
Authors: Arabindo Roy, Peter A. R. Ade, James J. Bock, Edward L. Chapin, Mark J. Devlin, Simon R. Dicker, Kevin France, Andrew G. Gibb, Matthew Griffin, Joshua O. Gundersen, Mark Halpern, Peter C. Hargrave, David H. Hughes, Jeff Klein, Gaelen Marsden, Peter G. Martin, Philip Mauskopf, Jorge L. Morales Ortiz, Calvin B. Netterfield, Alberto Noriega-Crespo, Luca Olmi, Guillaume Patanchon, Marie Rex, Douglas Scott, Christopher Semisch, Matthew D. P. Truch, Carole Tucker, Gregory S. Tucker, Marco P. Viero, Donald V. Wiebe
(Version, v2)

We present Cygnus X in a new multi-wavelength perspective based on an unbiased BLAST survey at 250, 350, and 500 micron, combined with rich datasets for this well-studied region. Our primary goal is to investigate the early stages of high mass star formation. We have detected 184 compact sources in various stages of evolution across all three BLAST bands. From their well-constrained spectral energy distributions, we obtain the physical properties mass, surface density, bolometric luminosity, and dust temperature. Some of the bright sources reaching 40 K contain well-known compact H II regions. We relate these to other sources at earlier stages of evolution via the energetics as deduced from their position in the luminosity-mass (L-M) diagram. The BLAST spectral coverage, near the peak of the spectral energy distribution of the dust, reveals fainter sources too cool (~ 10 K) to be seen by earlier shorter-wavelength surveys like IRAS. We detect thermal emission from infrared dark clouds and investigate the phenomenon of cold "starless cores" more generally. Spitzer images of these cold sources often show stellar nurseries, but these potential sites for massive star formation are "starless" in the sense that to date there is no massive protostar in a vigorous accretion phase. We discuss evolution in the context of the L-M diagram. Theory raises some interesting possibilities: some cold massive compact sources might never form a cluster containing massive stars; and clusters with massive stars might not have an identifiable compact cold massive precursor.

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Title: The BLAST Survey of the Vela Molecular Cloud: Dynamical Properties of the Dense Cores in Vela-D
Authors: Luca Olmi, Daniel Angles-Alcazar, Massimo De Luca, Davide Elia, Teresa Giannini, Dario Lorenzetti, Fabrizio Massi, Peter G. Martin, Francesco Strafella
(Version v2)

The Vela-D region, according to the nomenclature given by Murphy & May (1991), of the star forming complex known as the Vela Molecular Ridge (VMR), has been recently analysed in details by Olmi et al. (2009), who studied the physical properties of 141 pre- and proto-stellar cold dust cores, detected by the "Balloon-borne Large-Aperture Submillimeter Telescope'' (BLAST) during a much larger (55 sq. degree) Galactic Plane survey encompassing the whole VMR. This survey's primary goal was to identify the coldest, dense dust cores possibly associated with the earliest phases of star formation. In this work, the dynamical state of the Vela-D cores is analysed. Comparison to dynamical masses of a sub-sample of the Vela-D cores estimated from the 13CO survey of Elia et al. (2007), is complicated by the fact that the 13CO linewidths are likely to trace the lower density intercore material, in addition to the dense gas associated with the compact cores observed by BLAST. In fact, the total internal pressure of these cores, if estimated using the 13CO linewidths, appears to be higher than the cloud ambient pressure. If this were the case, then self-gravity and surface pressure would be insufficient to bind these cores and an additional source of external confinement (e.g., magnetic field pressure) would be required. However, if one attempts to scale down the 13CO linewidths, according to the observations of high-density tracers in a small sample of sources, then most proto-stellar cores would result effectively gravitationally bound.

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Title: The balloon-borne large-aperture submillimeter telescope for polarimetry: BLAST-Pol
Authors: Laura M. Fissel, Peter A. R. Ade, Francesco E. Angile, Steven J. Benton, Edward L. Chapin, Mark J. Devlin, Natalie N. Gandilo, Joshua O. Gundersen, Peter C. Hargrave, David H. Hughes, Jeffrey Klein, Andrei L. Korotkov, Galen Marsden, Tristan G. Matthews, Lorenzo Moncelsi, Tony K. Mroczkowski, C. Barth Netterfield, Giles Novak, Luca Olmi, Enzo Pascale, Giorgio Savini, Douglas Scott, Jamil A. Shariff, Juan Diego Soler, Nicholas E. Thomas, Matthew D. P. Truch, Carole E. Tucker, Gregory S. Tucker, Derek Ward-Thompson, Donald V. Wiebe

The Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLAST-Pol) is a suborbital mapping experiment designed to study the role played by magnetic fields in the star formation process. BLAST-Pol is the reconstructed BLAST telescope, with the addition of linear polarisation capability. Using a 1.8 m Cassegrain telescope, BLAST-Pol images the sky onto a focal plane that consists of 280 bolometric detectors in three arrays, observing simultaneously at 250, 350, and 500 um. The diffraction-limited optical system provides a resolution of 30'' at 250 um. The polarimeter consists of photolithographic polarising grids mounted in front of each bolometer/detector array. A rotating 4 K achromatic half-wave plate provides additional polarisation modulation. With its unprecedented mapping speed and resolution, BLAST-Pol will produce three-colour polarisation maps for a large number of molecular clouds. The instrument provides a much needed bridge in spatial coverage between larger-scale, coarse resolution surveys and narrow field of view, and high resolution observations of substructure within molecular cloud cores. The first science flight will be from McMurdo Station, Antarctica in December 2010. .

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