Abstract by Marta Sewilo
The Surveying the Agents of a Galaxy's Evolution (SAGE) Spitzer Legacy Programs provide a comprehensive picture of the current star formation activity in the Large (SAGE-LMC, Meixner et al. 2006) and Small (SAGE-SMC, Gordon et al. 2011) Magellanic Clouds which is traced by the IRAC (3.6, 4.5, 5.8, and 8.0 microns) and MIPS (24, 70, and 160 microns) bands. It allowed for the first time a global study of star formation in the Magellanic Clouds (MCs) at high enough resolution to resolve individual cores and protostars at a range of mid-IR wavelengths. The methods for searching and identifying Young Stellar Objects (YSOs) in the MCs will be discussed. These methods involve color-magnitude selections, inspection of the multi-wavelength images, and fitting of the spectral energy distributions of the YSO candidates using the 2D radiative transfer models (Robitaille et al. 2006).
The most recent data from the "HERschel Inventory of the Agents of Galaxy Evolution” (HERITAGE; Meixner et al. 2010) survey provided reliable longwave (100 - 500 microns) SEDs of large samples of Spitzer-identified high-mass YSOs, thus constraining their physical properties and evolutionary stages more precisely than was previously possible. Herschel also discovers the youngest YSOs whose SEDs peak in Herschel bands.
Relevant Papers
"Spitzer Sage Survey of the Large Magellanic Cloud. III. Star Formation and ~1000 New Candidate Young Stellar Objects"
Whitney et al. 2008
"High- and Intermediate-Mass Young Stellar Objects in the Large Magellanic Cloud"
Gruendl and Chu 2009
"The youngest massive protostars in the Large Magellanic Cloud"
Sewilo et al. 2010
Talk Slides
pdf
Friday, May 27, 2011
Friday, May 13, 2011
Not Your Grandmother's HII Regions: An X-ray Tour of Massive Star-forming Regions
Abstract by Leisa Townsley
The Chandra X-ray Observatory is providing remarkable new views of massive star-forming regions, revealing all stages in the life cycle of high-mass stars and their effects on their surroundings. We will tour several such regions, highlighting physical processes that characterize the life of a cluster of massive stars, from deeply-embedded cores too young to have established an HII region to superbubbles so large that they shape our views of galaxies. Along the way we see that X-ray observations reveal hundreds of pre-main sequence stars accompanying the massive stars that power great HII region complexes. The most massive stars themselves are often anomalously hard X-ray emitters; this may be a new indicator of close binarity or strong magnetic fields. These complexes are sometimes suffused by diffuse X-ray structures, signatures of multi-million-degree plasmas created by fast O-star winds. In older regions we see the X-ray remains of the deaths of massive stars that stayed close to their birthplaces, exploding as cavity supernovae within the superbubbles that these clusters created.
Relevant Papers
"The Integrated Diffuse X-ray Emission of the Carina Nebula Compared to Other Massive Star-forming Regions", Townsley et al. 2011
Talk Slides
pdf
The Chandra X-ray Observatory is providing remarkable new views of massive star-forming regions, revealing all stages in the life cycle of high-mass stars and their effects on their surroundings. We will tour several such regions, highlighting physical processes that characterize the life of a cluster of massive stars, from deeply-embedded cores too young to have established an HII region to superbubbles so large that they shape our views of galaxies. Along the way we see that X-ray observations reveal hundreds of pre-main sequence stars accompanying the massive stars that power great HII region complexes. The most massive stars themselves are often anomalously hard X-ray emitters; this may be a new indicator of close binarity or strong magnetic fields. These complexes are sometimes suffused by diffuse X-ray structures, signatures of multi-million-degree plasmas created by fast O-star winds. In older regions we see the X-ray remains of the deaths of massive stars that stayed close to their birthplaces, exploding as cavity supernovae within the superbubbles that these clusters created.
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| 30 Doradus (Chandra soft X-rays in red, MCELS H-alpha in green, Spitzer 8 microns in blue) |
Relevant Papers
"The Integrated Diffuse X-ray Emission of the Carina Nebula Compared to Other Massive Star-forming Regions", Townsley et al. 2011
Talk Slides
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