Astronomy and Astrophysics Seminars

Stellar-mass black holes in young massive and open clusters and their role in gravitational-wave generation

by Dr. Sambaran Banerjee (Argelander Institute of Astronomy, University of Bonn, Germany)

Thursday, April 25, 2019 from to (Asia/Kolkata)
at A269
 Star clusters serve as a factory of a variety of astrophysical phenomena by virtue of their high density of stars and a deep potential well, promoting close encounters. In this talk, I shall focus on one highly-contextual aspect that interests me greatly, namely, stellar-remnant black holes (BH) in clusters. Through dynamical interactions, such BHs in dense stellar clusters trigger general-relativistic inspiral and merger of binary black holes (BBH), detectable by LISA and LIGO-Virgo. In my studies, state-of-the-art schemes for stellar wind and remnant formation are adopted in realistic models of young massive and open clusters which are evolved ab initio via relativistic, direct N-body computations. The dynamically-triggred BBH mergers obtained in these computations are consistent with the to-date LIGO-observed BBH merger events. They also suggest that dynamical BBH mergers from young massive and open clusters would add up to merger rates comparable to those from more massive globular and nuclear clusters. I shall also touch upon our other star cluster-related works such as runaway massive stars from young clusters, stellar collision products, and birth conditions of clusters.