Globular cluster ultraluminous X-ray sources in the furthest early-type galaxies
Abstract
Ultraluminous X-ray sources (ULXs) in globular clusters (GCs) are low-mass X-ray binaries that achieve high X-ray luminosities through a currently uncertain accretion mechanism. Using archival Chandra and Hubble Space Telescope observations, we perform a volume-limited search (≲70 Mpc) of 21 of the most massive ($\gt 10^{11.5} \, \mathrm{M}_\odot$) early-type galaxies to identify ULXs hosted by GC candidates. We find a total of 34 ULX candidates above the expected background within five times the effective radius of each galaxy, with 10 of these ($\sim 29.4{{\ \rm per\ cent}}$) potentially hosted by a GC. A comparison of the spatial and luminosity distributions of these new candidate GC ULXs with previously identified GC ULXs shows that they are similar: both samples peak at LX ~ a few × 1039 erg s-1 and are typically located within a few effective radii of their host galaxies.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- January 2023
- DOI:
- 10.1093/mnras/stac3244
- arXiv:
- arXiv:2211.07699
- Bibcode:
- 2023MNRAS.518.3386T
- Keywords:
-
- accretion;
- accretion discs;
- stars: black holes;
- X-rays: binaries;
- Astrophysics - High Energy Astrophysical Phenomena;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- Accepted for publication in MNRAS. 10 pages, 4 figures, 5 tables