A bright off-nuclear X-ray source: a type IIn supernova, a bright ULX or a recoiling supermassive black hole in CXOJ122518.6+144545
Abstract
In this paper we report the discovery of CXOJ122518.6+144545, a peculiar X-ray source with a position 3.6 +/- 0.2 arcsec off-nuclear from a Sloan Digital Sky Survey Data Release 7 (SDSS DR7) z = 0.0447 galaxy. The 3.6 arcsec offset corresponds to 3.2 kpc at the distance of the galaxy. The 0.3-8keV X-ray flux of this source is 5 × 10-14ergcm-2s-1and its 0.3-8keV luminosity is 2.2 × 1041ergs-1 (2.7 × 1041ergs-1 0.5-10keV) assuming that the source belongs to the associated galaxy. We find a candidate optical counterpart in archival Hubble Space Telescope/Advanced Camera for Surveys g'-band observations of the field containing the galaxy obtained on 2003 June 16. The observed magnitude of g' = 26.4 +/- 0.1 corresponds to an absolute magnitude of -10.1. We discuss the possible nature of the X-ray source and its associated candidate optical counterpart and conclude that the source is either a very blue Type IIn supernova, an ultraluminous X-ray source with a very bright optical counterpart or a recoiling supermassive black hole.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- September 2010
- DOI:
- 10.1111/j.1365-2966.2010.16943.x
- arXiv:
- arXiv:1004.5379
- Bibcode:
- 2010MNRAS.407..645J
- Keywords:
-
- galaxies: individual: SDSS J122518.86+144547.7;
- X-rays: binaries;
- X-rays: individual: CXOJ122518.6+144545;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 6 pages, 3 figures, accepted for publication in MNRAS