BHI Colloquium


Monday, December 13, 2021, 11:00am to 12:00pm

Lieke van Son (Astronomy) - Harvard University

Title: The redshift evolution of the binary black hole merger rate: a weighty matter.

Abstract: Current gravitational wave detectors are starting to reveal the redshift evolution of the binary black hole (BBH) merger rate, and third-generation detectors promise to probe BBH mergers across all redshifts of interest to stellar mass BHs. The redshift evolution of the BBH merger rate contains valuable information on the BH progenitors and their birth environment. To access this information, we first need to understand the delay time: the time between progenitor-star formation, and the time of the BBH merger event. Because we cannot observe delay time directly, we need to associate trends in delay time to observable source properties, such as BH-mass. I will discuss what correlations we expect between BH-mass and delay times from the perspective of isolated binary evolution. Specifically, we find that isolated binaries cannot form BHs with high mass and short delay times. This leads to the surprising prediction that the relative contribution of more massive BHs to the mass distribution decays towards higher redshift. Such predictions can be tested with future detectors, and I will discuss the implications of both a confirmation and a non-detection.

Bio: Lieke is a PhD student in the BinCosmos group which is spread over the CfA and the API, University of Amsterdam. Her research interests include gravitational wave progenitors, binary evolution, massive stars and their role in galaxy formation.

See also: Astronomy