Constraints on a strong X - ray flare in the Seyfert galaxy MCG - 6 - 30 - 15

We discuss implications of a strong flare event observed in the Seyfert galaxy MCG-6-30-15 assuming that the emission is due to localized magnetic reconnection. We conduct detailed radiative transfer modeling of the reprocessed radiation for a primary source that is elevated above the disk. The model includes relativistic effects and Keplerian motion around the black hole. We show that for such a model setup the observed time-modulation must be intrinsic to the primary source. Using a simple analytical model we then investigate time delays between hard and soft X-rays during the flare. The model considers an intrinsic delay between primary and reprocessed radiation, which measures the geometrical distance of the flare source to the reprocessing sites. The observed time delays are well reproduced if one assumes that the reprocessing happens in magnetically confined, cold clouds. The Seyfert galaxy MCG-6-30-15 was observed for 95 ksec with XMM-Newton in the year 2000 (Wilms et al. 2001). The X-ray lightcurve of this observation reveals a strong flare event of which Ponti et al. (2004) conducted a detailed analysis. In this proceedings note we discuss the possibility that the flare is produced by localized magnetic reconnec-tion and we constrain some details of such a flare setup. We imagine that the strong flare in MCG-6-30-15 originates in a compact reconnection site elevated to a height H above the surface of the accretion disk. The radiation from this primary source partly shines toward the disk and creates a hot spot. The distance of the spot's center to the disk center is denoted by r. The flare is supposed to be in Keplerian co-rotation with the disk and we assume that the primary illumination sets on and fades out instantaneously. The irradiation of the disk then evolves across the hot spot, starting from the spot center and progressing toward the border. Therefore we expect the lightcurve of the reprocessed radiation to be curved even if the time evolution of the primary is box-shaped. We want to model the exact shape of the lightcurve expected from such a flare setup at different orbital phases of the disk. We first conduct detailed local radiative transfer computations. The varying intensity of the irradiation across the hot spot is taken into account as well as the angular dependence of the reprocessed emission. The vertical structure of the disk is assumed to remain in the same hydrostatic equilibrium as before the onset …