STELLAR X-RAY SOURCES IN THE CHANDRA COSMOS SURVEY

Journal Article · Fri Dec 10 00:00:00 EST 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/725/1/480· OSTI ID:21474401

Wright, N J; Drake, J J; Civano, F ^[1]

---

1. Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

We present an analysis of the X-ray properties of a sample of solar- and late-type field stars identified in the Chandra Cosmic Evolution Survey (COSMOS), a deep (160 ks) and wide ({approx}0.9 deg{sup 2}) extragalactic survey. The sample of 60 sources was identified using both morphological and photometric star/galaxy separation methods. We determine X-ray count rates, extract spectra and light curves, and perform spectral fits to determine fluxes and plasma temperatures. Complementary optical and near-IR photometry is also presented and combined with spectroscopy for 48 of the sources to determine spectral types and distances for the sample. We find distances ranging from 30 pc to {approx}12 kpc, including a number of the most distant and highly active stellar X-ray sources ever detected. This stellar sample extends the known coverage of the L{sub X}-distance plane to greater distances and higher luminosities, but we do not detect as many intrinsically faint X-ray sources compared to previous surveys. Overall the sample is typically more luminous than the active Sun, representing the high-luminosity end of the disk and halo X-ray luminosity functions. The halo population appears to include both low-activity spectrally hard sources that may be emitting through thermal bremsstrahlung, as well as a number of highly active sources in close binaries.

• OSTI ID: 21474401
• Journal Information: Astrophysical Journal, Vol. 725, Issue 1; Other Information: DOI: 10.1088/0004-637X/725/1/480; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
BREMSSTRAHLUNG
COSMIC X-RAY SOURCES
ELECTRON TEMPERATURE
GALACTIC EVOLUTION
GALAXIES
ION TEMPERATURE
LUMINOSITY
PHOTOMETRY
SPECTROSCOPY
STAR EVOLUTION
SUN
UNIVERSE
COSMIC RAY SOURCES
ELECTROMAGNETIC RADIATION
EVOLUTION
MAIN SEQUENCE STARS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIATIONS
STARS