ITC Pizza Lunch - Erin Kara (Maryland)


Wednesday, February 14, 2018, 11:00am to 12:00pm



"Observations of Super-Eddington Accretion in the Local Universe"

Abstract:  Some of the most massive black holes known in the Universe are also the most distant, formed when the Universe was less than a billion years old. This begs the question: how can a ten billion solar mass black holes form in such a short period of time? Rapid accretion at rates exceeding the Eddington Limit—where outward radiation pressure equals to the inward gravitational force—may provide the answer.  Understanding the physics of Super-Eddington accretion is vital for understanding how black holes grow and has motivated several analytical, numeral and observational efforts. In this talk, I will review several recent observations of super-Eddington accretors in the local universe, including Tidal Disruption Events, where a star gets ripped apart from the strong tidal forces of a supermassive black hole, and Ultraluminous X-ray Sources, which are off-nuclear sources radiating at luminosities greater than 10^39 erg/s (e.g. 10 times the Eddington luminosity for a 10 solar mass black hole).  These observations together with recent magnetohydrodynamical simulations are putting new constraints on the geometry and kinematics of super-Eddington accretion around black holes.

See also: Pizza Lunch, 2017-18