Spitzer View of Young Massive Stars in the LMC HII Complexes. II. N159

Abstract

The HII complex N159 in the Large Magellanic Cloud (LMC) is used to study massive star formation in different environments, as it contains three giant molecular clouds (GMCs) that have similar sizes and masses but exhibit different intensities of star formation. We identify candidate massive young stellar objects (YSOs) using infrared photometry, and model their SEDs to constrain mass and evolutionary state. Good fits are obtained for less evolved Type I, I/II, and II sources. Our analysis suggests that there are massive embedded YSOs in N159B, a maser source, and several ultracompact HII regions. Massive O-type YSOs are found in GMCs N159-E and N159-W, which are associated with ionized gas, i.e., where massive stars formed a few Myr ago. The third GMC, N159-S, has neither O-type YSOs nor evidence of previous massive star formation. This correlation between current and antecedent formation of massive stars suggests that energy feedback is relevant. We present evidence that N159-W is forming YSOs spontaneously, while collapse in N159-E may be triggered. Finally, we compare star formation rates determined from YSO counts with those from integrated H-alpha and 24 micron luminosities and expected from gas surface densities. Detailed dissection of extragalactic GMCs like the one presented here is key to revealing the physics underlying commonly used star formation scaling laws.

60 pages, 11 figures. Accepted for publication in Astrophysical Journal

References in corpus (10)

• Infrared Emission from Interstellar Dust. IV. The Silicate-Graphite-PAH Model in the Post-Spitzer Era
• The Resolved Properties of Extragalactic Giant Molecular Clouds
• Spitzer SAGE survey of the Large Magellanic Cloud II: Evolved Stars and Infrared Color Magnitude Diagrams
• Triggered star formation on the borders of the Galactic HII region RCW 82
• The Evolution of Massive YSOs in the LMC: Part I. Identification and Spectral Classification
• The Spitzer Survey of the Small Magellanic Cloud: Discovery of Embedded Protostars in the HII Region NGC 346
• Sub-millimeter Observations of Giant Molecular Clouds in the Large Magellanic Cloud: Temperature and Density as Determined from J=3-2 and J=1-0 transitions of CO
• Emission from Very Small Grains and PAH Molecules in Monte Carlo Radiation Transfer Codes: Application to the Edge-On Disk of Gomez's Hamburger
• Spectroscopic study of the N159/N160 complex in the Large Magellanic Cloud
• Cluster Formation in Contracting Molecular Clouds

Cited by in corpus (26)

• Star-formation rates from young-star counts and the structure of the ISM across the NGC346/N66 complex in the SMC
• Kinetic temperature of massive star forming molecular clumps measured with formaldehyde. II. The Large Magellanic Cloud
• The Molecular Clouds Fueling a 1/5 Solar Metallicity Starburst
• First extragalactic measurement of the turbulence driving parameter: ALMA observations of the star-forming region N159E in the Large Magellanic Cloud
• Kinetic temperature of massive star-forming molecular clumps measured with formaldehyde IV. The ALMA view of N113 and N159W in the LMC
• Complex Organic Molecules in Star-Forming Regions of the Magellanic Clouds
• An ALMA study of the massive molecular clump N159W-North in the Large Magellanic Cloud: A possible gas flow penetrating one of the most massive protocluster systems in the Local Group
• Massive young stellar objects in the Local Group irregular galaxy NGC6822 identified using machine learning
• Spitzer View of Massive Star Formation in the Tidally Stripped Magellanic Bridge
• DeGaS-MC: Dense Gas Survey in the Magellanic Clouds I -- An APEX survey of HCO+ and HCN(2-1) toward the LMC and SMC
• ALMA Resolves Giant Molecular Clouds in a Tidal Dwarf Galaxy
• Enhancement of CO(3-2)/CO(1-0) Ratios and Star Formation Efficiencies in Supergiant HII Regions
• The Young Stellar Population of the metal-poor galaxy NGC 6822
• ALMA Observations of Giant Molecular Clouds in M33. II. Triggered High-mass Star Formation by Multiple Gas Colliding Events at the NGC 604 Complex
• ALMA Observations of HCO+ and HCN Emission in a massive star forming region N55 of the Large Magellanic Cloud
• Optimal correction of distortion for High Angular Resolution images. Application to GeMS data
• Structural and Dynamical Analysis of the Quiescent Molecular Ridge in the Large Magellanic Cloud
• The Detection of Deuterated Water in the Large Magellanic Cloud with ALMA
• Massive young stellar objects in the Local Group spiral galaxy M33 identified using machine learning
• On the limitations of H alpha luminosity as a star formation tracer in spatially resolved observations
• ALMA Observations of the Molecular Clouds in NGC 625
• Properties of star formation of the Large Magellanic Cloud as probed by young stellar objects
• Massive Star Formation in the LMC. I. N159 and N160 Complexes
• Physical Conditions in the LMC's Quiescent Molecular Ridge: Fitting Non-LTE Models to CO Emission
• Near-Infrared Polarimetric Study of N159/N160 Star-Forming Complex in the Large Magellanic Cloud
• Correction of distortion for optimal image stacking in Wide Field Adaptive Optics: Application to GeMS data