Physical Properties and Evolutionary Stages of Massive Young Stellar Objects in the Large Magellanic Cloud
University of Virginia, Charlottesville, Virginia, U.S.A.
University of Virginia, Charlottesville, Virginia, U.S.A., and National Radio Astronomical Observatory, Charlottesville, Virginia, U.S.A.
University of Illinois, Urbana, Illinois, U.S.A.
University of Illinois, Urbana, Illinois, U.S.A.
University of Illinois, Urbana, Illinois, U.S.A.
University of Illinois, Urbana, Illinois, U.S.A.
Space Science Institute, Boulder, Colorado, U.S.A.
Abstract
Massive stars drive the evolution of galactic interstellar media, yet their formation remains poorly understood. We use Spitzer Infrared Spectrometer (IRS) observations of 277 massive young stellar objects (YSOs) in the Large Magellanic Cloud (LMC) and combine them with multi-wavelength photometry from U to 70 micrometer to construct and model their spectral energy distribution (SED) and to deduce their mass and evolutionary stage. We also examine the immediate interstellar and stellar environment using high-resolution optical and near-IR images to assess the origin of dust emission and multiplicity of sources. Some of these YSOs are spatially coincident with known masers and ultracompact HII regions that can be used as an independent check on the feasibility of SED fits. Comparisons among YSOs’ physical properties, immediate stellar and interstellar environment, and mid-IR spectral features are used to discuss evolution of massive YSOs in the LMC.