Astronomy and Astrophysics – Astrophysics
Scientific paper
2003-09-25
Astron.Astrophys.413:895-902,2004
Astronomy and Astrophysics
Astrophysics
9 pages, 6 figures. Accepted for publication in Astronomy & Astrophysics
Scientific paper
10.1051/0004-6361:20034050
We present the broad band analysis of two BeppoSAX observations of the Sy 1 Mkn509. In 2000 the source was in a typical flux state, F{2-10keV}=2.7x10^{-11}erg cm^{-2} s^{-1}, while in 1998 it was found in a high flux state, F{2-10keV}=5.7x10^{-11} erg cm^{-2} s^{-1}. A comparison between the two states shows a energy-dependent flux variation. A soft excess, a narrow iron line and a Compton reflection hump above 10 keV, are clearly apparent in the residuals after fitting the spectra with a simple power law. We tested two alternative models. In the first the iron line and the high energy bump are well reproduced by reprocessing in a cold and Compton thick material. The intensity of the iron line (also consistent with a Chandra measurement) as well as the normalization of the reflection hump are consistent with a constant in the two epochs: this, combined with the fact that the line is narrow as observed by Chandra, suggests a common origin from distant and optically thick matter. This model further requires a component to model the soft excess: the empirical choice of two black bodies accounts well for the excess in both observations, their combined strength was a factor about three higher in the high than in the low flux state defined above. However the relative contribution of the soft excess is higher in the low flux state. In the second model we attempted to reproduce all spectral features, except for the narrow cold line, with reflection from an ionized disc. This model is successful only in the high flux state,but it fails in the low flux state, when the soft excess is only partially accounted for. In either models, the slope of the power law is larger in the high than in the low flux state, in agreement with a behaviour known to be shared by several objects of the same type.
Matt Giorgia
Perola Giuseppe Cesare
Piro Luigi
Rosa Adriano de
No associations
LandOfFree
Close and distant reprocessing media in Mkn509 studied with BeppoSAX does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Close and distant reprocessing media in Mkn509 studied with BeppoSAX, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Close and distant reprocessing media in Mkn509 studied with BeppoSAX will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-55603