Presentation Abstract

Presentation Number 341.17
Presentation Time: Wednesday, Jan 11, 2012, 9:00 AM - 6:30 PM
Title An Analysis of Ultra-luminous X-ray Sources in Interacting Arp Galaxies
Author Block Jacob A. Burleson1, B. J. Smith2, D. A. Swartz3, O. Miller1, M. A. Nowak4, C. J. Struck5
1University of Alabama in Huntsville, 2East Tennessee State University, 3Universities Space Research Association NASA/MSFC, 4MIT - CXC, 5Iowa State University.
Abstract We have conducted a statistical analysis of the ultra-luminous X-ray point sources (ULXs) in all of the galaxies in the Arp Atlas of Peculiar Galaxies that have archival Chandra data and Sloan Digitized Sky Survey optical images. We find no excess of ULXs relative to the stellar mass in these peculiar galaxies; however, the subset of strongly interacting galaxies have a possible enhancement of a factor of ∼3 in their number of ULXs per unit optical luminosity. Such an enhancement would be expected if ULX production is related to star formation, as interacting galaxies tend to have enhanced star formation rates on average. We find a possible enhancement in the number of ULXs in tidal features of the interacting galaxies compared to inner disks and to a sample of spiral galaxies. The Arp sample includes a few, relatively distant, LIRGs. We find a deficiency of ULXs per unit far-IR luminosity in these galaxies. In these systems, AGNs may contribute to powering the far-infrared at the expense of star formation; alternatively, ULXs may be highly obscured in the X-ray in these galaxies and therefore not detected by these Chandra observations which suffer from incompleteness in these distant galaxies. Finally, we compare the ULX luminosity function to that of normal spiral galaxies.
This research was supported by Chandra Award Numbers AR9-0010A, GO9-0098X, and GO0-11099A issued by the Chandra X-ray Observatory Center.