Letter to the Editor

Generation of massive stellar black holes by rapid gas accretion in primordial dense clusters

¹ Centre for Theoretical Physics, The British University in Egypt, Sherouk City 11837, Cairo, Egypt
e-mail: zaroupas@gmail.com
² Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA

Received: 28 October 2019
Accepted: 21 November 2019

Abstract

Supernova theory suggests that black holses of a stellar origin cannot attain masses in the range of 50−135 solar masses in isolation. We argue here that this mass gap is filled in by black holes that grow by gas accretion in dense stellar clusters, such as protoglobular clusters. The accretion proceeds rapidly, during the first 10 megayears of the cluster life, before the remnant gas is depleted. We predict that binaries of black holes within the mass gap can be observed by LIGO.