The Discovery of Quasi-soft and Supersoft Sources in External Galaxies
Abstract
We apply a uniform procedure to select very soft sources from point sources observed by Chandra in 4 galaxies. This sample includes one elliptical galaxy (NGC 4967), 2 face-on spirals (M101 and M83), and an interacting galaxy (M51). We have found very soft X-ray sources (VSSs) in every galaxy. Some of these fit the criteria for canonical supersoft sources (SSSs), while others are somewhat harder. These latter have characteristic values of kT < 300 eV; we refer to them as quasisoft sources (QSSs). We found a combined total of 149 VSSs in the 4 galaxies we considered; 77 were SSSs and 72 were QSSs. (See the paper for the original long abstract)
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 2004
- DOI:
- 10.1086/421318
- arXiv:
- arXiv:astro-ph/0311375
- Bibcode:
- 2004ApJ...609..710D
- Keywords:
-
- Black Hole Physics;
- Galaxies: Individual: Messier Number: M51;
- Galaxies: Individual: Messier Number: M83;
- Galaxies: Individual: Messier Number: M101;
- Galaxies: Individual: NGC Number: NGC 4697;
- ISM: Supernova Remnants;
- Stars: White Dwarfs;
- X-Rays: Binaries;
- X-Rays: Galaxies;
- Astrophysics
- E-Print:
- 20 pages, 6 figures. Accepted for publication in ApJ