Triple and Quadruple Black Holes in the ASTRID Simulation at $z \sim 2$

Calvin Hoffman; Nianyi Chen; Tiziana Di Matteo; Yueying Ni; Simeon Bird; Rupert Croft; Abraham Loeb

doi:10.1093/mnras/stad1929

paper

Triple and Quadruple Black Holes in the ASTRID Simulation at $z \sim 2$

arXiv:2303.04825 · doi:10.1093/mnras/stad1929

Abstract

We use the ASTRID cosmological hydrodynamic simulation to investigate the properties and evolution of triple and quadruple Massive Black Hole (MBH) systems at $z = 2 - 3$ . Only a handful of MBH tuple systems have been detected to date. In ASTRID, we find $4%$ of the $M_{BH} > 1 0^{7} M_{⊙}$ are in tuples with $Δ r_{max} < 200 kpc$ . The tuple systems span a range of separations with the majority of the observable AGN systems at $Δ r \sim 50 - 100$ kpc. They include some of the most massive BHs (up to $1 0^{10} M_{⊙}$ ) but with at least one of the components of $M_{BH} \sim 1 0^{7} M_{⊙}$ . Tuples' host galaxies are typically massive with $M_{*} \sim 1 0^{10 - 11} M_{⊙}$ . We find that $> 10%$ massive halos with $M_{halo} > 1 0^{13} M_{⊙}$ host MBH tuples. Following the subsequent interactions between MBHs in tuples, we found that in $\sim 5%$ of the triplets all three MBHs merge within a Gyr, and $15%$ go through one merger. As a by-product of the complex multi-galaxy interaction of these systems, we also find that up to $\sim 5%$ of tuples lead to runaway MBHs. In ASTRID, virtually all of the ultramassive black holes ( $> 1 0^{10} M_{⊙}$ ) have undergone a triple quasar phase while for BHs with $M_{BH} \sim 1 0^{9} M_{⊙}$ this fraction drops to $50%$ .

10 pages, 9 figures; comments welcome

References in corpus (16)

Cited by in corpus (1)

A candidate quadruple AGN system at $z \sim 3$

Triple and Quadruple Black Holes in the ASTRID Simulation at z∼2

Abstract

References in corpus (16)

Cited by in corpus (1)

Triple and Quadruple Black Holes in the ASTRID Simulation at $z \sim 2$