Daily Image
17-05-2018
Today's colloquium: The different regimes of accretion and feedback in compact objects
| Submitter: | Tobias Beuchert |
| Description: | Compact accreting objects like black holes (BHs) and neutron stars (NSs) concentrate their mass on extremely compact scales and are found across the entire Universe. In the process of accretion, these engines convert gravitational potential energy into strong radiation and massive outflows. Besides wide angle winds, jets clearly reflect the most extreme and least well understood feedback mechanism. In jets, matter is accelerated to relativistic speeds and focused within small solid angles. Related BH engines have been influential throughout the formation of the universe. In my talk, I will discuss Active Galactic Nuclei, which harbor supermassive BHs. I focus on the prominent and nearby example of a young radio galaxy, PKS 1718-649, that shows jetted feedback still being embedded in its galactic cradle. I present recent and intriguing results that tentatively draft a coherent picture. On one hand, we investigated the large-scale environment and its X-ray signatures. On the other hand, we anticipate to probe the innermost parsec-scale environment of this AGN by searching for correlated free-free and photo-absorption simultaneously in the radio and X-rays. While the time scales of ongoing processes are very long in Active Galaxies, they break down to the observable regime in stellar-mass NSs or BHs accreting from a companion star. I am presenting a novel method to study the extremes of accretion-feedback in so-called "Ultraluminous X-ray Sources". Me and my collaborators anticipate to self-consistently describe the extended and ionized nebulae observed around many of these objects with physical descriptions of the underlying feedback mechanisms. |
| Copyright: | M. Boeck (2012), PhD thesis |
| Tweet |  |