Constraints on a soft X-ray excess in the quasar 3C 279
Abstract
We present the results of a three-week daily monitoring campaign of the quasar 3C 279 by the X-ray satellites RXTE ROSAT. A cross-correlation provides no evidence for any time lag between the very similar soft and hard X-ray light curves, and the source shows no significant spectral variability over the observing period. There is no evidence to support the presence of a soft excess, with a 99 per cent upper limit on any such component of 25 per cent of the total observed luminosity in the 0.1-2 keV band (<3x10^38W). This fraction (but not the luminosity) is significantly lower than that of the soft excess observed in 3C 273.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- November 1998
- DOI:
- 10.1046/j.1365-8711.1998.01954.x
- arXiv:
- arXiv:astro-ph/9809308
- Bibcode:
- 1998MNRAS.300.1023L
- Keywords:
-
- GALAXIES: ACTIVE;
- QUASARS: INDIVIDUAL: 3C 279;
- X-RAYS: GALAXIES;
- Astrophysics
- E-Print:
- 4 pages, 3 figures, accepted for publication in MNRAS. Style files needed: epsf, mn.sty and new_cite.sty (this last is included in submission)