CANDIDATE X-RAY-EMITTING OB STARS IN THE CARINA NEBULA IDENTIFIED VIA INFRARED SPECTRAL ENERGY DISTRIBUTIONS

Journal Article · Sun May 01 04:00:00 EDT 2011 · Astrophysical Journal, Supplement Series

DOI:https://doi.org/10.1088/0067-0049/194/1/6· OSTI ID:21560396

Povich, Matthew S; Townsley, Leisa K; Broos, Patrick S; Getman, Konstantin V ^[1]; Gagne, Marc ^[2]; Babler, Brian L; Meade, Marilyn R; Townsend, Richard H. D. ^[3]; Indebetouw, Remy; Majewski, Steven R ^[4]

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1. Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)
2. Department of Geology and Astronomy, West Chester University, West Chester, PA 19383 (United States)
3. Department of Astronomy, University of Wisconsin, 475 N. Charter Street, Madison, WI 53706 (United States)
4. Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States)

We report the results of a new survey of massive, OB stars throughout the Carina Nebula using the X-ray point source catalog provided by the Chandra Carina Complex Project (CCCP) in conjunction with infrared (IR) photometry from the Two Micron All-Sky Survey and the Spitzer Space Telescope Vela-Carina survey. Mid-IR photometry is relatively unaffected by extinction, hence it provides strong constraints on the luminosities of OB stars, assuming that their association with the Carina Nebula, and hence their distance, is confirmed. We fit model stellar atmospheres to the optical (UBV) and IR spectral energy distributions (SEDs) of 182 OB stars with known spectral types and measure the bolometric luminosity and extinction for each star. We find that the extinction law measured toward the OB stars has two components: A{sub V} = 1-1.5 mag produced by foreground dust with a ratio of total-to-selective absorption R{sub V} = 3.1 plus a contribution from local dust with R{sub V} > 4.0 in the Carina molecular clouds that increases as A{sub V} increases. Using X-ray emission as a strong indicator of association with Carina, we identify 94 candidate OB stars with L{sub bol} {approx}> 10{sup 4} L{sub sun} by fitting their IR SEDs. If the candidate OB stars are eventually confirmed by follow-up spectroscopic observations, the number of cataloged OB stars in the Carina Nebula will increase by {approx}50%. Correcting for incompleteness due to OB stars falling below the L{sub bol} cutoff or the CCCP detection limit, these results potentially double the size of the young massive stellar population.

• OSTI ID: 21560396
• Journal Information: Astrophysical Journal, Supplement Series, Journal Name: Astrophysical Journal, Supplement Series Journal Issue: 1 Vol. 194; ISSN 0067-0049; ISSN APJSA2
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ATMOSPHERES
CATALOGS
DATA ANALYSIS
DOCUMENT TYPES
ELECTROMAGNETIC RADIATION
EMISSION
ENERGY SPECTRA
INFRARED RADIATION
IONIZING RADIATIONS
NEBULAE
PHOTOMETRY
POINT SOURCES
RADIATION SOURCES
RADIATIONS
SPECTRA
STARS
STELLAR ATMOSPHERES
X RADIATION
X-RAY SOURCES