University of Connecticut

Events Calendar

Special Astronomy Seminar

Friday, July 26, 2019
2:00pm – 3:00pm

Storrs Campus
Gant West P121

Prof. Keith Horne, University of St. Andrews

Echo Tomography of Black Hole Accretion Flows in Active Galactic Nuclei

Echo Tomography uses light travel time delays to resolve micro-arcsecond structure of black hole accretion flows in active galactic nuclei. I will discuss methods used to map the temperature-radius profile of black hole accretion discs, and to construct velocity-delay maps that probe the geometry, kinematics and ionisation structure of the associated broad emission-line regions. In particular, I will present results from the 2014 STORM campaign using HST, Swift, and ground-based telescopes to monitor spectral variations in the Seyfert galaxy NGC 5548. I will discuss anomalous behaviour observed during the campaign, and present a determination of the inclination and temperature-radius profile of its accretion disc and velocity-delay maps exhibiting evidence for an inclined Keplerian flow extending from 2 to 20 light days. Tilting the inner disc to align with black hole spin may help to address several features we are seeing in the reverberation mapping studies.


Dr. A. Huang

Physics Department (primary)

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