317 citations · 3.8k across the 172 of their papers we have counts for
10 papers · 2 filters
Variation of the primary and reprocessed radiation in the flare-spot model
M. Dovciak, V. Karas, G. Matt +1
We study light curves and spectra (equivalent widths of the iron line and some other spectral characteristics) which arise by reprocessing on the surface of an accretion disc, foll…
Modeling an accretion disc stochastical variability
T. Pechacek, V. Karas
Hot spots residing on the surface of an accretion disc have been considered as a model of short-term variability of active galactic nuclei. In this paper we apply the theory of ran…
Flares from spiral waves by lensing and time-delay amplification?
V. Karas, M. Dovciak, A. Eckart +1
Episodically accreting black holes are thought to produce flares when a chunk of particles is accelerated to high velocity near the black hole horizon. This also seems to be the ca…
Iron lines from transient and persisting hot spots on AGN accretion disks
R. W. Goosmann, M. Mouchet, B. Czerny +4
[abridged] We model the X-ray reprocessing from a strong co-rotating flare above an accretion disk in active galactic nuclei. We explore the horizontal structure and evolution of t…
On the orientation of the Sagittarius A* system
L. Meyer, R. Schoedel, A. Eckart +3
The near-infrared emission from the black hole at the Galactic center (Sgr A*) has unique properties. The most striking feature is a suggestive periodic sub-structure that has been…
Enhanced activity of massive black holes by stellar capture assisted by a self-gravitating accretion disc
V. Karas, L. Subr
We study the probability of close encounters between stars from a nuclear cluster and a massive black hole. The gravitational field of the system is dominated by the black hole in…