MODELING THE REDSHIFT EVOLUTION OF THE NORMAL GALAXY X-RAY LUMINOSITY FUNCTION

Journal Article · Wed Mar 20 04:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/766/1/19· OSTI ID:22167591

Tremmel, M. ^[1]; Fragos, T.; Zezas, A. ^[2]; Lehmer, B. D.; Tzanavaris, P. ^[3]; Belczynski, K. ^[4]; Kalogera, V.; Farr, W. M. ^[5]; Basu-Zych, A. R.; Hornschemeier, A.; Jenkins, L.

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1. Department of Astronomy, University of Washington, Box 351580, U.W., Seattle, WA 98195-1580 (United States)
2. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
3. The Johns Hopkins University, Homewood Campus, Baltimore, MD 21218 (United States)
4. Astronomical Observatory, University of Warsaw, Al. Ujazdowskie 4, 00-478 Warsaw (Poland)
5. Center for Interdisciplinary Research and Exploration in Astrophysics and Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States)

Emission from X-ray binaries (XRBs) is a major component of the total X-ray luminosity of normal galaxies, so X-ray studies of high-redshift galaxies allow us to probe the formation and evolution of XRBs on very long timescales ({approx}10 Gyr). In this paper, we present results from large-scale population synthesis models of binary populations in galaxies from z = 0 to {approx}20. We use as input into our modeling the Millennium II Cosmological Simulation and the updated semi-analytic galaxy catalog by Guo et al. to self-consistently account for the star formation history (SFH) and metallicity evolution of each galaxy. We run a grid of 192 models, varying all the parameters known from previous studies to affect the evolution of XRBs. We use our models and observationally derived prescriptions for hot gas emission to create theoretical galaxy X-ray luminosity functions (XLFs) for several redshift bins. Models with low common envelope efficiencies, a 50% twins mass ratio distribution, a steeper initial mass function exponent, and high stellar wind mass-loss rates best match observational results from Tzanavaris and Georgantopoulos, though they significantly underproduce bright early-type and very bright (L{sub x} > 10{sup 41}) late-type galaxies. These discrepancies are likely caused by uncertainties in hot gas emission and SFHs, active galactic nucleus contamination, and a lack of dynamically formed low-mass XRBs. In our highest likelihood models, we find that hot gas emission dominates the emission for most bright galaxies. We also find that the evolution of the normal galaxy X-ray luminosity density out to z = 4 is driven largely by XRBs in galaxies with X-ray luminosities between 10{sup 40} and 10{sup 41} erg s{sup -1}.

• OSTI ID: 22167591
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 766; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CATALOGS
EMISSION
GALAXY NUCLEI
LUMINOSITY
MASS TRANSFER
PROBES
RED SHIFT
SIMULATION
STARS
STELLAR WINDS
X RADIATION
X-RAY GALAXIES