Description | Join us for a colloquium with Dr. Saavik Ford from the Borough of Manhattan Community College/City University of New York. Title: “The AGN Channel for Binary Black Hole Mergers Detected in Gravitational Waves” Abstract: Binary black hole (BBH) mergers were first detected using gravitational waves (GW) in 2015. Since then, nearly 100 further detections have been made, and we can expect a total of 250-300 by the end of the ongoing O4 run of the LIGO-Virgo-KAGRA collaboration; however the astrophysical origin of these systems remains unclear. Active Galactic Nuclei (AGN) provide one possible location for these BBH mergers. Excitingly, the AGN channel provides the best hope of finding direct EM counterparts to BBH mergers, and that has further utility in providing an independent measure of the Hubble constant. But: AGN themselves remain uncertain in many of their physical paramters, notably lifetime, radial extent, aspect ratio, and gas density, despite our study of them using EM waves for over 80 years. Such uncertainties have important implications for a variety of fields, including galaxy evolution and LCDM cosmology. I will discuss the astrophysical motivations for the AGN channel, and how we can use GW observations of BBH mergers to learn more about AGN themselves, along with their impact on multiple other areas of astrophysics. I will also discuss the various predictions of the AGN channel and how we can test them, with special attention to results we expect from O4. You can attend this event in-person in PAA A118 or via Zoom: https://washington.zoom.us/j/98982151598 |
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