Minimum gas mass accreted by spinning intermediate-mass black holes in stellar clusters

Abstract

The spin of intermediate-mass black holes (IMBHs) growing through repeated black hole mergers in stellar clusters statistically asymptotes to zero. Putative observations of IMBHs with dimensionless spin parameter $\chi \gtrsim 0.6$ would require a phase of coherent gas accretion to spin up the black hole. We estimate the amount of gas necessary to produce a given IMBH spin. If the observed IMBH mass and spin are $M\gtrsim 1000M_{\odot }$ and $\chi \gtrsim 0.6$, respectively, the IMBH must have coherently accreted at least $\sim 100M_{\odot }$ of gas. In this scenario, as long as the spin is not maximal, the IMBH can only accrete at most half of its mass. Our estimates can constrain the relative contribution of accretion and mergers to the growth of IMBHs in dense stellar environments.

10 pages, 7 figures, matches published version

References in corpus (14)

• The Evolution of Black Hole Mass and Spin in Active Galactic Nuclei
• Observational evidence for intermediate-mass black holes
• Fast-moving stars around an intermediate-mass black hole in Omega Centauri
• Hunting for Massive Black Holes in Dwarf Galaxies
• Sensitivity of gravitational wave searches to the full signal of intermediate mass black hole binaries during the LIGO O1 Science Run
• Simulations predict intermediate-mass black hole formation in globular clusters
• The growth of intermediate mass black holes through tidal captures and tidal disruption events
• Black-hole mergers in disklike environments could explain the observed $q$-${\chi }_{\mathrm{eff}}$ correlation
• Isolated and dynamical black hole mergers with \texttt{B-POP}: the role of star formation and dynamics, star cluster evolution, natal kicks, mass and spins, and hierarchical mergers
• Growing Black Holes through Successive Mergers in Galactic Nuclei: I. Methods and First Results
• Massive black hole assembly in nuclear star clusters
• Avoiding a Cluster Catastrophe: Retention Efficiency and the Binary Black Hole Mass Spectrum
• Opportunities and limits of lunar gravitational-wave detection
• Intermediate-mass black hole binary parameter estimation with next-generation ground-based detector networks