Exploring the Influence of Metallicity on X-ray Binary Formation in Nearby and Distant UV-selected Galaxies
Abstract
We present our research on the relationship between the 2-10 keV X-ray luminosity, assumed to originate from X-ray binaries (XRBs), and star formation rate (SFR) in rest-frame UV-selected galaxies across cosmic time -- ranging from Lyman break galaxies (LBGs) in the early Universe (z=1.5-4) to Lyman break analogs (LBAs) in the present-day Universe ( 0.1). Using the recently acquired 4Ms Chandra Deep Field South (CDF-S) data, we perform X-ray stacking on ~4000 z=1.5-4 LBGs and find that the 2-10 keV X-ray luminosity per SFR evolves mildly with redshift, consistent with X-ray binary population synthesis models. Our Chandra observations of 4 GALEX-selected 0.1 LBAs, which are individually X-ray detected, demonstrate elevated X-ray/SFR ratios compared to local galaxies, but similar to z>2 LBGs. This implies that the relatively metal-poor, dust-free, high mode of star formation in LBAs and distant LBGs may yield higher total HMXB luminosity than found in lower SFR galaxies in the local Universe.
- Publication:
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AAS/High Energy Astrophysics Division #13
- Pub Date:
- April 2013
- Bibcode:
- 2013HEAD...1330104B