A Pan-Carina Young Stellar Object Catalog: Intermediate-mass Young Stellar Objects in the Carina Nebula Identified Via Mid-infrared Excess Emission

Type Journal Article
Names Matthew S. Povich, Nathan Smith, Steven R. Majewski, Konstantin V. Getman, Leisa K. Townsley, Brian L. Babler, Patrick S. Broos, Rémy Indebetouw, Marilyn R. Meade, Thomas P. Robitaille, Keivan G. Stassun, Barbara A. Whitney, Yoshinori Yonekura, Yasuo
Publication The Astrophysical Journal Supplement Series
Volume 194
Issue 1
Pages 14
Date May 1, 2011
Short Title A Pan-Carina Young Stellar Object Catalog
URL http://adsabs.harvard.edu/abs/2011ApJS..194...14P
Library Catalog NASA ADS
Abstract We present a catalog of 1439 young stellar objects (YSOs) spanning the 1.42 deg2 field surveyed by the Chandra Carina Complex Project (CCCP), which includes the major ionizing clusters and the most active sites of ongoing star formation within the Great Nebula in Carina. Candidate YSOs were identified via infrared (IR) excess emission from dusty circumstellar disks and envelopes, using data from the Spitzer Space Telescope (the Vela-Carina survey) and the Two-Micron All Sky Survey. We model the 1-24 μm IR spectral energy distributions of the YSOs to constrain physical properties. Our Pan-Carina YSO Catalog (PCYC) is dominated by intermediate-mass (2 M sun < m <~ 10 M sun) objects with disks, including Herbig Ae/Be stars and their less evolved progenitors. The PCYC provides a valuable complementary data set to the CCCP X-ray source catalogs, identifying 1029 YSOs in Carina with no X-ray detection. We also catalog 410 YSOs with X-ray counterparts, including 62 candidate protostars. Candidate protostars with X-ray detections tend to be more evolved than those without. In most cases, X-ray emission apparently originating from intermediate-mass, disk-dominated YSOs is consistent with the presence of low-mass companions, but we also find that X-ray emission correlates with cooler stellar photospheres and higher disk masses. We suggest that intermediate-mass YSOs produce X-rays during their early pre-main-sequence evolution, perhaps driven by magnetic dynamo activity during the convective atmosphere phase, but this emission dies off as the stars approach the main sequence. Extrapolating over the stellar initial mass function scaled to the PCYC population, we predict a total population of >2 × 104 YSOs and a present-day star formation rate (SFR) of >0.008 M sun yr-1. The global SFR in the Carina Nebula, averaged over the past ~5 Myr, has been approximately constant.
Tags ISM: individual objects: NGC 3372, Mass Function, STARS: FORMATION, X-rays: stars, circumstellar matter, stars: luminosity function, stars: pre-main sequence
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