High-energy monitoring of Seyfert galaxies: the case of NGC 5548 and NGC 4593
Abstract
We discuss results of broad-band monitoring programs on the active galactic nuclei (AGNs) NGC 5548 and NGC 4593, focusing on the high-energy view with XMM, NuSTAR and INTEGRAL. NGC 5548 was the object of a successful multi-satellite campaign conducted from May 2013 to February 2014, during which the source appeared unusually obscured by a clumpy stream of ionized gas, causing strong absorption in the X-ray band and simultaneous deep, broad UV absorption troughs (Kaastra et al. 2014). A talk giving an overview of the campaign on NGC 5548 is also proposed at this conference (Cappi et al.). Concerning NGC 4593, it was the object of a monitoring program of 5 × 20 ks joint XMM/NuSTAR observations in January 2015, spaced by two days. In both cases, the availability of multiple, broad-band observations with a high signal-to-noise ratio allows us to disentangle the different spectral components present in the high-energy spectrum and properly study their variability. The use of realistic Comptonization models provides good constraints on the physical parameters of the hot corona responsible for the hard X-ray emission.
- Publication:
-
The Extremes of Black Hole Accretion
- Pub Date:
- July 2015
- Bibcode:
- 2015ebha.confE..65U