Astronomy & Astrophysics Seminar: Binary Supermassive Black Holes: A bridge Between Galaxy Evolution and Gravitational Wave Astrophysics

Zoom: https://tau-ac-il.zoom.us/j/87230679135?pwd=Y1duRlArUkJwSnhaaXVscUU0azY3Zz09

Abstract:

Binary supermassive black holes are an almost inevitable outcome of massive galaxy mergers. Their orbital evolution has been the subject of a great deal of theoretical work for decades. Some observed candidates have been reported and the detection of a low-frequency gravitational wave background corroborates the existence of such a population at intermediate redshifts. Our community also expects the detection of individual merging systems in the next decade or so by the Pulsar Timing Arrays (PTAs) and the Laser Interferometer Space Antena (LISA).

In this talk I will summarize scenarios for the evolution of supermassive and introduce the basic principles of characterizing the gravitational wave signals of individual systems. I will then describe two efforts by my collaborators, our students, and myself. One effort is directed at finding and evaluating candidate supermassive binaries via optical spectroscopy. We seek binaries at separations of a fraction of a parsec, which would be the progenitors of low-frequency gravitational wave sources. Finding them is useful in constraining models for their orbital evolution. Another effort, which I will describe only briefly, is aimed at preparing strategies for the identification of the electromagnetic counterparts of supermassive binaries detected by LISA.
 

Seminar Organizer: Dr. Jonathan Stern