Intermediate-mass Black Holes from High Massive-star Binary Fractions in Young Star Clusters
Abstract
Black holes formed in dense star clusters, where dynamical interactions are frequent, may have fundamentally different properties than those formed through isolated stellar evolution. Theoretical models for single-star evolution predict a gap in the black hole mass spectrum from roughly 40–120 M⊙ caused by (pulsational) pair-instability supernovae. Motivated by the recent LIGO/Virgo event GW190521, we investigate whether black holes with masses within or in excess of this "upper-mass gap" can be formed dynamically in young star clusters through strong interactions of massive stars in binaries. We perform a set of N-body simulations using the CMC cluster-dynamics code to study the effects of the high-mass binary fraction on the formation and collision histories of the most massive stars and their remnants. We find that typical young star clusters with low metallicities and high binary fractions in massive stars can form several black holes in the upper-mass gap and often form at least one intermediate-mass black hole. These results provide strong evidence that dynamical interactions in young star clusters naturally lead to the formation of more massive black hole remnants.
Additional Information
© 2021 The American Astronomical Society. Received 2020 December 18; revised 2021 January 20; accepted 2021 January 21; published 2021 February 19. We are grateful to Mario Spera for key insights during the development of this project and we thank him for a careful reading of the manuscript. We thank the anonymous referee for helpful comments. This work was supported by NSF Grants AST-1757792 and AST-1716762 at Northwestern University. N.W. acknowledges support from the CIERA Riedel Graduate Fellowship as well as the NSF GK-12 Fellowship Program under Grant DGE-0948017. K.K. is supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-2001751. G.F. acknowledges support from a CIERA Fellowship at Northwestern University. Computations were made possible through the resources and staff contributions provided for the Quest high-performance computing facility at Northwestern University. S.C. acknowledges support of the Department of Atomic Energy, Government of India, under project No. 12-R&D-TFR-5.02-0200.Attached Files
Published - González_2021_ApJL_908_L29.pdf
Accepted Version - 2012.10497.pdf
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Additional details
- Eprint ID
- 108127
- Resolver ID
- CaltechAUTHORS:20210219-120713619
- AST-1757792
- NSF
- AST-1716762
- NSF
- Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA)
- DGE-0948017
- NSF Graduate Research Fellowship
- AST-2001751
- NSF Astronomy and Astrophysics Fellowship
- 12-R&D-TFR-5.02-0200
- Department of Atomic Energy (India)
- Created
-
2021-02-19Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field
- Caltech groups
- TAPIR