Description
Chairman: Włodek Kluźniak
Different types of astrophysical black hole sources show variable accretion flows. They are found in gamma ray bursts, active galactic nuclei and radio loud objects such as blazars. These objects often have relativistic jets pointing at a small angle from our line of sight. Observational studies have found correlations between the minimum variability time-scale and Lorentz factor for these...
We investigate the accretion induced spin up of the black hole via numerical simulations. Our method is based on general-relativistic hydrodynamics of the slowly-rotating flows in the Kerr metric. We account for the changing black hole mass and spin during accretion. We study non-magnetized flows with shocks, and finally, we also include magnetic field endowed in the gas. The aim...
Accretion disks in High mass X-ray binaries (HMXB's) are mostly fed by the stellar wind from their companion star. These winds also affect the observed X-ray spectra arising from the hot coronal flow.
Cygnus X-1 and its companion star, HDE-226868 is one of such HMXBs. It is one of the brightest X-ray sources observed and shows the X-ray intensity variations in both the soft and hard X-rays....