Dr. Luigi Gallo is a Professor and Chair of the Department of Astronomy and Physics at Saint Mary's University. His research interests include the study of high energy X-rays emitted from black holes and active galactic nuclei. He also plays an active role in the definition and realization of future X-ray missions including Hitomi and the recently launched XRISM X-ray observatories led by JAXA and NASA.
Title: The ins and outs of black hole accretion
Abstract: Contrary to the general consensus, black holes are not giant monsters that suck up everything in their surroundings. There is a finely tuned balance between material that falls toward the black hole and material that is ejected from the system. The X-ray data from active galactic nuclei (AGN) are ideal for examining the inward accretion disc flow and the energetic winds that launch material into the host galaxy impacting its evolution. In this talk I will present observations of AGN from various telescopes that allow us to probe these investigations. I will describe the eclipse of NGC 6814 captured with XMM-Newton that revealed the properties and location of the absorber, and even the size of the X-ray corona. I will describe how the high-resolution XRISM observations of the prototypical ultrafast outflow in PDS 456 have altered our view of winds, and how multi-component fitting of iron emission discloses its origin and flow. Together, all this information helps us build a more complete understanding of how black holes accrete and dispel material.