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The variable XMM-Newton spectrum of Markarian 766

M. J. Page·K. O. Mason·F. J. Carrera·J. Clavel·J. S. Kaastra·E. M. Puchnarewicz·M. Santos-Lleo·H. Brunner·C. Ferrigno·I. M. George·F. Paerels·K. A. Pounds·S. P. Trudolyubov
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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.

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M. J. Page, K. O. Mason, F. J. Carrera, J. Clavel, J. S. Kaastra, E. M. Puchnarewicz, M. Santos-Lleo, H. Brunner, C. Ferrigno, I. M. George, F. Paerels, K. A. Pounds, S. P. Trudolyubov. 2000-11-13. The variable XMM-Newton spectrum of Markarian 766. https://doi.org/10.1051/0004-6361%3A20000240

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