MIT Astrophysics Colloquium 11/22/2022 — Mapping Close To Black Holes With Their Noisy Accretion Flows (speaker: Phil Uttley, University Of Amsterdam)
Tuesday November 22, 2022 10:00 am
via Zoom only
Note: this talk will be held at 10:00am EST via zoom
Accreting stellar-mass black holes in X-ray binary systems show X-ray variations over a broad range of time-scales, which are generated by mass-accretion fluctuations arising in the turbulent accretion flow. The variability is noise-like, but with certain plausible assumptions, we can use it to map the emitting regions close to the black hole by studying the response of distinct spectral components: the blackbody-emitting accretion disk and the optically-thin corona. In this talk I will show how these ‘X-ray spectral-timing’ properties can be used to interpret the variability. I will demonstrate how the interactions of disk and corona can explain most of the known variability properties and allow us to infer both the coronal geometry and the propagation-speed and radial extent of the mass-accretion fluctuations. With these properties we can shed new light on the nature and evolution of accreting black holes across the mass scale.