The lecture by Ramesh Narayan will be held on June 21st, at 3 pm in the lecture hall of the Nicolaus Copernicus Astronomical Center, Warsaw, ul. Bartycka 18.
"Accretion Disks, Jets, and Black Hole Spin"
Ramesh Narayan (Center for Astrophysics, Harvard University)
Abstract: An astrophysical black hole is fully described with only two parameters: mass and spin. This simplicity makes the black hole a perfect laboratory for exploring both the physics of accretion disks and the mechanisms by which accreting black holes eject relativistic jets. Using a combination of numerical simulations and observational data, we have studied the properties of accretion disks near and inside the innermost stable circular orbit around a spinning black hole. These studies have enabled us to measure spin parameters of ten stellar-mass black holes. We find an intriguing correlation between the radio power of relativistic jets and black hole spin parameter. This is the first direct evidence that jets may be powered by black hole spin energy.