Rosie Chen (Max-Planck-Institut für Radioastronomie)

Spitzer's View of Massive Star Formation in the Magellanic System - Rosie Chen Colloquium

ATNF Marsfield Lecture Theatre

Abstract

Abstract:
Recent Spitzer mid-IR surveys reveal a large number of individually
resolved massive young stellar objects (YSOs) in the Magellanic Clouds,
providing an excellent opportunity to study massive star formation at
metallicity and galactic environment different from the Galaxy. We have
used Spitzer and complementary near-IR and optical data to study massive
YSOs in HII complexes in the LMC and SMC and high N(HI) portion of
Magellanic Bridge (Chen et al. 2009, 2010, 2011). We have modeled
spectral energy distributions of YSOs and found their masses ranging
4-45 Mo in the LMC/SMC, while 4-10 Mo in the Bridge. To assess the
environmental effects, we have estimated the instantaneous star
formation efficiency (SFE) using complete lists of YSOs in the LMC and
Bridge. We found that the LMC has ~3 times higher SFE than the Bridge,
but the trend reverses at N(HI) < 10^21 cm^-2. This reverse is likely
caused by different formation mechanisms of molecular clouds, such as
colliding flows.