2008/03/13 by Douglas A. Swartz, Roberto Soria, Allyn F. Tennant · 1 citation
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1086/587776
Accepted to ApJ
arxiv created 2008/03/13 · openalex publication_date 2008/08/26 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
A thorough search for ultraluminous X-ray source candidates within the Local Volume is made. The search spatially matches potential ULXs detected in X-ray images or cataloged in the literature with galaxies tabulated in the Catalog of Neighboring Galaxies compiled by Karachentsev et al. The specific ULX frequency (occurrence rate per unit galaxy mass) is found to be a decreasing function of host galaxy mass for host masses above ~10 8.5 M ☉ . There is too little mass in galaxies below this point to determine whether this trend continues to lower galaxy mass. No ULXs have yet been detected in lower mass galaxies. Systematic differences between dwarf and giant galaxies that may explain an abundance of ULXs in dwarf galaxies and what they may imply about the nature of ULXs are discussed.