Dr. George Chartas (Penn State Univ.) visit our group and give colloquium speech

Oct 10, 2008

“Inflows and Outflows from Supermassive Black Holes”

The current paradigm for the AGN phenomenon is a central engine that consists of an inflow of hot material accreting in the form of a disk onto a supermassive black hole. Recent observations also find powerful and high velocity ionized material outflowing from the black hole.

I will present recent X-ray observations of AGN that suggest the presence of near-relativistic outflows of ionized absorbing material with velocities of up to 0.7c. These studies indicate that these winds may be important in regulating the growth of the supermassive black hole, controlling the formation of the host galaxy, and enriching the intergalactic medium.

Based on our recent X-ray and optical observations of AGN with highly blueshifted narrow and broad absorption lines I will present a unified picture to describe the outflow properties of most quasars.

Regarding studies of quasar inflows, direct imaging of the accretion disks of black holes requires angular resolutions of the order of tens of nano-arcseconds at redshifts of about 1. I will show that by employing natures own telescopes we can indirectly image quasar accretion disks by multi-wavelength monitoring of microlensing events in AGN.