The ultraluminous X-ray sources NCG 1313 X-1/X-2
Abstract
We present the results of a detailed analysis of the available X-ray and optical data of the two Ultraluminous X-ray Sources hosted in the nearby spiral galaxy NGC 1313, namely NGC 1313 X-1 and X-2. Both NGC 1313 X-1 and X-2 show soft components in their XMM EPIC spectra. If they originate from an accretion disk, the inferred mass of the compact remnant is about 100 M_sun, making them intermediate mass black holes. New optical and Chandra observations of the field around NGC 1313 X-2 allow us to identify a R=21.6 point-like object as the possible counterpart. The value of the X-ray/optical flux ratio, the X-ray variability history and the spectral distribution derived from a re-analysis of the ROSAT, ASCA and XMM data indicate a luminous X-ray binary in NGC 1313 as a likely explanation for NGC 1313 X-2. The derived optical luminosity is consistent with that of a 15-20 M_sun companion. Evidence for the presence of spectral features in the XMM EPIC pn spectra of both NGC 1313 X-1 and X-2 has recently been found.
- Publication:
-
35th COSPAR Scientific Assembly
- Pub Date:
- 2004
- Bibcode:
- 2004cosp...35.3749T