D. Grupe, S. Komossa, L. C. Gallo, A. L. Longinotti, A. C. Fabian, A. K. Pradhan, M. Grubenbauer, D. Xu
The Narrow-line Seyfert 1 galaxy (NLS1) Mkn 335 is remarkable because it has
repeatedly shown deep, long X-ray low-states which show pronounced spectral
structure. It has become one of the prototype AGN in deep minimum X-ray states.
Here we report on the continuation of our ongoing monitoring campaign with
Swift and the examination of the low state X-ray spectra based on a 200 ks
triggered observation with XMM in June 2009. Swift has continuously monitored
Mkn 335 since May 2007 typically on a monthly basis. This is one of the longest
simultaneous UV/X-ray light curves so far obtained for an active galactic
nucleus (AGN). Mkn 335 has shown strong X-ray variability even on time scales
of hours. In the UV, it turns out to be one of the most variable among NLS1s.
Long-term Swift monitoring allow us to examine correlations between the UV,
X-rays and X-ray hardness ratios. We find no significant correlation or lag
between the UV and X-ray variability; however, we do find distinct trends in
the behavior of the hardness ratio variability. The hardness ratio and count
rate are correlated in the low-flux state, but no correlation is seen in the
high-state. The X-ray low-state spectra of the 2007 and 2009 XMM observations
display significant spectral variability. We fit the X-ray spectra with a suite
of phenomenological models in order to characterize the data. The broad band
CCD spectrum can be fitted equally well with partial absorption and blurred
reflection models. These more complicated models are explored in further detail
in upcoming work.
View original:
http://arxiv.org/abs/1202.4692
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