The variable XMM-Newton spectrum of Markarian 766
Abstract
The narrow-line Seyfert 1 galaxy Markarian 766 was observed for 60 ks with the XMM-Newton observatory. The source shows a complex X-ray spectrum. The 2-10 keV spectrum can be adequately represented by a power law and broad Fe Ka emission. Between 0.7 and 2 keV the spectrum is harder and exhibits a flux deficit with respect to the extrapolated medium energy slope. Below 0.7 keV, however, there is a strong excess of emission. The RGS spectrum shows an edge-like feature at 0.7 keV; the energy of this feature is inconsistent with that expected for an OVII edge from a warm absorber. Markarian 766 varies by a factor of ~ 2 in overall count rate in the EPIC and RGS instruments on a timescale of a few thousand seconds, while no significant flux changes are observed in the ultraviolet with the OM. The X-ray variability is spectrally dependent with the largest amplitude variability occurring in the 0.4-2 keV band. The spectral variability can be explained by a change in flux and slope of the medium energy continuum emission, superimposed on a less variable (or constant) low energy emission component.
Cite
@article{arxiv.astro-ph/0011242,
title = {The variable XMM-Newton spectrum of Markarian 766},
author = {M. J. Page and K. O. Mason and F. J. Carrera and J. Clavel and J. S. Kaastra and E. M. Puchnarewicz and M. Santos-Lleo and H. Brunner and C. Ferrigno and I. M. George and F. Paerels and K. A. Pounds and S. P. Trudolyubov},
journal= {arXiv preprint arXiv:astro-ph/0011242},
year = {2009}
}
Comments
6 pages, 6 figures, Accepted by A&A for publication in the Special Issue on 1st science with XMM Newton