Mass-gap Mergers in Active Galactic Nuclei
arXiv:2012.00011 · doi:10.3847/1538-4357/abd555
Abstract
The recently discovered gravitational wave sources GW190521 and GW190814 have shown evidence of BH mergers with masses and spins that could be outside of the range expected from isolated stellar evolution. These merging objects could have undergone previous mergers. Such hierarchical mergers are predicted to be frequent in active galactic nuclei (AGN) disks, where binaries form and evolve efficiently by dynamical interactions and gaseous dissipation. Here we compare the properties of these observed events to the theoretical models of mergers in AGN disks, which are obtained by performing one-dimensional -body simulations combined with semi-analytical prescriptions. The high BH masses in GW190521 are consistent with mergers of high-generation (high-g) BHs where the initial progenitor stars had high metallicity, 2g BHs if the original progenitors were metal-poor, or 1g BHs that had gained mass via super-Eddington accretion. Other measured properties related to spin parameters in GW190521 are also consistent with mergers in AGN disks. Furthermore, mergers in the lower mass gap or those with low mass ratio as found in GW190814 and GW190412 are also reproduced by mergers of 2g-1g or 1g-1g objects with significant accretion in AGN disks. Finally, due to gas accretion, the massive neutron star merger reported in GW190425 can be produced in an AGN disk.
12 pages, 4 figures, accepted in ApJ
References in corpus (26)
- Cosmic Star Formation History
- GW190814: Gravitational Waves from the Coalescence of a 23 M Black Hole with a 2.6 M Compact Object
- GW190521: A Binary Black Hole Merger with a Total Mass of
- Properties and astrophysical implications of the 150 Msun binary black hole merger GW190521
- Gravitational waves from scattering of stellar-mass black holes in galactic nuclei
- A Global Three Dimensional Radiation Magneto-hydrodynamic Simulation of Super-Eddington Accretion Disks
- Candidate Electromagnetic Counterpart to the Binary Black Hole Merger Gravitational Wave Event S190521g
- Mind the gap: The location of the lower edge of the pair instability supernovae black hole mass gap
- Starbursts near supermassive black holes: young stars in the Galactic Center, and gravitational waves in LISA band
- Estimating the final spin of a binary black hole coalescence
- A Highly Spinning and Aligned Binary Black Hole Merger in the Advanced LIGO First Observing Run
- Simulations of star formation in a gaseous disc around sgr A* - a failed AGN
- Gravitational waves and mass ejecta from binary neutron star mergers: Effect of the mass-ratio
- On the rate of black hole binary mergers in galactic nuclei due to dynamical hardening
- AGN Disks Harden the Mass Distribution of Stellar-mass Binary Black Hole Mergers
- Large scale kinematics and dynamical modelling of the Milky Way nuclear star cluster
- Exploring the Lower Mass Gap and Unequal Mass Regime in Compact Binary Evolution
- GW190521 may be an intermediate mass ratio inspiral
- The Population III origin of GW190521
- GW190412 as a Third-Generation Black Hole Merger from a Super Star Cluster
- Formation and merging of Mass Gap Black Holes in Gravitational Wave Merger Events from Wide Hierarchical Quadruple Systems
- Astrophysical implications of GW190412 as a remnant of a previous black-hole merger
- Making massive stars in the Galactic Centre via accretion onto low-mass stars within an accretion disc
- Dynamical evolution of Population III stellar systems and the resulting binary statistics
- Was GW190412 born from a hierarchical 3+1 quadruple configuration?
- Revealing the Formation of the Milky Way Nuclear Star Cluster via Chemo-Dynamical Modeling