The Role of High-mass Stellar Binaries in the Formation of High-mass Black Holes in Dense Star Clusters

Abstract

Recent detections of gravitational waves from mergers of binary black holes (BBHs) with pre-merger source-frame individual masses in the so-called upper mass-gap, expected due to (pulsational) pair instability supernova ((P)PISN), have created immense interest in the astrophysical production of high-mass black holes (BHs). Previous studies show that high-mass BHs may be produced via repeated BBH mergers inside dense star clusters. Alternatively, inside dense star clusters, stars with unusually low core-to-envelope mass ratios can form via mergers of high-mass stars, which then can avoid (P)PISN, but produce high-mass BHs via mass fallback. We simulate detailed star-by-star multi-physics models of dense star clusters using the Monte Carlo cluster evolution code, CMC, to investigate the role of primordial binary fraction among high-mass stars (>=15 Msun) on the formation of high-mass BHs. We vary the high-mass stellar binary fraction (fb_15_prime) while keeping all other initial properties, including the population of high-mass stars, unchanged. We find that the number of high-mass BHs, as well as the mass of the most massive BH formed via stellar core-collapse are proportional to fb_15_prime. In contrast, there is no correlation between fb_15_prime and the number of high-mass BHs formed via BH-BH mergers. Since the total production of high-mass BHs is dominated by BH-BH mergers in old clusters, the overall number of high-mass BHs produced over the typical lifetime of globular clusters is insensitive to fb_15_prime. We study the differences in the demographics of BH-BH mergers and their implications for the LIGO-Virgo-Kagra detections as a function of fb_15_prime.

19 pages, 15 figures, and 2 tables; in press for publication in the Astrophysical Journal

References in corpus (31)

• Array Programming with NumPy
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• Binary interaction dominates the evolution of massive stars
• GWTC-3: Compact Binary Coalescences Observed by LIGO and Virgo During the Second Part of the Third Observing Run
• GW190521: A Binary Black Hole Merger with a Total Mass of $150M_{\odot }$
• Mind the gap: The location of the lower edge of the pair instability supernovae black hole mass gap
• MOCCA-SURVEY Database I: Coalescing Binary Black Holes Originating From Globular Clusters
• COSMIC Variance in Binary Population Synthesis
• The Dynamical Evolution of Stellar Black Holes in Globular Clusters
• Merging black holes in young star clusters
• 4-OGC: Catalog of gravitational waves from compact-binary mergers
• Constraints from gravitational wave detections of binary black hole mergers on the ${}^{12}\mathrm{C}{\left(\alpha ,\gamma \right)}^{16}\mathrm{O}$ rate
• Stellar-mass black holes in young massive and open stellar clusters and their role in gravitational-wave generation
• Formation of GW190521 from stellar evolution: the impact of the hydrogen-rich envelope, dredge-up and ${}^{12}$C($\alpha$, $\gamma$)${}^{16}$O rate on the pair-instability black hole mass gap
• Stellar-mass black holes in young massive and open stellar clusters and their role in gravitational-wave generation II
• Populating the upper black hole mass gap through stellar collisions in young star clusters
• Formation and evolution of compact binaries in globular clusters: I.Binaries with white dwarfs
• Binary black holes in young star clusters: the impact of metallicity
• Maximum Black Hole mass across Cosmic Time
• Modeling Dense Star Clusters in the Milky Way and Beyond with the Cluster Monte Carlo Code
• Intermediate-mass Black Holes from High Massive-star Binary Fractions in Young Star Clusters
• Black Hole Mergers from Hierarchical Triples in Dense Star Clusters
• Dynamical Formation of Low-Mass Merging Black Hole Binaries like GW151226
• Preparing the next gravitational million-body simulations: Evolution of single and binary stars in Nbody6++GPU, MOCCA and McLuster
• The Stellar Merger Scenario for Black Holes in the Pair-instability Gap
• GW190412 as a Third-Generation Black Hole Merger from a Super Star Cluster
• Formation of black holes in the pair-instability mass gap: evolution of a post-collision star
• Black Hole Mergers from Star Clusters with Top-Heavy Initial Mass Functions
• Compact Object Modeling in the Globular Cluster 47 Tucanae
• Formation of black holes in the pair-instability mass gap: Hydrodynamical simulations of a head-on massive star collision
• Intermediate-mass Black Holes on the Run from Young Star Clusters