Chandra Survey of Nearby Galaxies: The Catalog

Journal Article · Wed Feb 01 04:00:00 EST 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/835/2/223· OSTI ID:22663659

She, Rui; Feng, Hua ^[1]; Ho, Luis C. ^[2]

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1. Department of Engineering Physics and Center for Astrophysics, Tsinghua University, Beijing 100084 (China)
2. Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100087 (China)

We searched the public archive of the Chandra X-ray Observatory as of 2016 March and assembled a sample of 719 galaxies within 50 Mpc with available Advanced CCD Imaging Spectrometer observations. By cross-correlation with the optical or near-infrared nuclei of these galaxies, 314 of them are identified to have an X-ray active galactic nucleus (AGN). The majority of them are low-luminosity AGNs and are unlikely X-ray binaries based upon their spatial distribution and luminosity functions. The AGN fraction is around 60% for elliptical galaxies and early-type spirals, but drops to roughly 20% for Sc and later types, consistent with previous findings in the optical. However, the X-ray survey is more powerful in finding weak AGNs, especially from regions with active star formation that may mask the optical AGN signature. For example, 31% of the H ii nuclei are found to harbor an X-ray AGN. For most objects, a single power-law model subject to interstellar absorption is adequate to fit the spectrum, and the typical photon index is found to be around 1.8. For galaxies with a non-detection, their stacked Chandra image shows an X-ray excess with a luminosity of a few times 10{sup 37} erg s{sup −1} on average around the nuclear region, possibly composed of faint X-ray binaries. This paper reports on the technique and results of the survey; in-depth analysis and discussion of the results will be reported in forthcoming papers.

• OSTI ID: 22663659
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 835; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION
CATALOGS
CHARGE-COUPLED DEVICES
CORRELATIONS
DETECTION
GALAXY NUCLEI
IMAGES
LUMINOSITY
PHOTONS
RESPIRATORS
SPATIAL DISTRIBUTION
SPECTRA
SPECTROMETERS
STARS
X RADIATION
X-RAY GALAXIES