Dr. Joey Neilsen

Boston University

Accretion and Ejection Physics around Black Holes: X-ray Spectroscopy and Variable Outflows

In the last decade, radio and X-ray observations of stellar-mass black holes have revolutionized our understanding of the physics of accretion and ejection in strong gravitational fields. We now know that black holes can launch not only powerful relativistic jets that dominate the energetics of the accretion flow, but also highly-ionized winds that carry away the vast majority of the infalling gas. In this talk, I will focus on recent efforts to understand the role of these accretion disk winds, which may carry away as much as 25x more matter than reaches the black hole, and exert a powerful influence on the black hole feeding rate. After summarizing the current picture of accreting stellar mass black holes and reviewing a few major developments from the last decade, I will present some new results from our recent studies of winds, including some of the deepest absorption lines and the fastest wind variability ever observed by Chandra. I will discuss how high-resolution X-ray spectroscopy continues to provide new insights into the complex processes that govern black hole accretion.

Back to Spring 2013 Astrophysics Seminars

Received Jan 25, 2013