Merging of unequal mass binary black holes in non-axisymmetric galactic nuclei

• Verfasst von: Berczik, Peter [VerfasserIn]
• Verfasst von: Arca Sedda, Manuel [VerfasserIn]
• Verfasst von: Sobolenko, Margaryta [VerfasserIn]
• Verfasst von: Ishchenko, Marina [VerfasserIn]
• Verfasst von: Sobodar, Olexander [VerfasserIn]
• Verfasst von: Spurzem, Rainer [VerfasserIn]
• Titel: Merging of unequal mass binary black holes in non-axisymmetric galactic nuclei
• Verf.angabe: Peter Berczik, Manuel Arca Sedda, Margaryta Sobolenko, Marina Ishchenko, Olexander Sobodar, and Rainer Spurzem
• E-Jahr: 2022
• Jahr: 13 July 2022
• Umfang: 7 S.
• Fussnoten: Gesehen am 28.10.2022
• Titel Quelle: Enthalten in: Astronomy and astrophysics
• Ort Quelle: Les Ulis : EDP Sciences, 1969
• Jahr Quelle: 2022
• Band/Heft Quelle: 665(2022), Artikel-ID A86, Seite 1-7
• ISSN Quelle: 1432-0746
• DOI: doi:10.1051/0004-6361/202244354
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1820318559

Abstract

In this work, we study the stellar-dynamical hardening of unequal mass supermassive black hole (SMBH) binaries in the central regions of merging galactic nuclei. We present a comprehensive set of direct <i>N<i/>-body simulations of the problem, varying both the total mass and the mass ratio of the SMBH binary (SMBHB). Simulations were carried out with the <i>φ<i/>-GPU <i>N<i/>-body code, which enabled us to fully exploit supercomputers equipped with graphic processing units (GPUs). As a model for the galactic nuclei, we adopted initial axisymmetric, rotating models, aimed at reproducing the properties of a galactic nucleus emerging from a galaxy merger event, containing two SMBHs which were unbound initially. We found no ‘final-parsec problem’, as our SMBHs tend to pair and shrink without showing significant signs of stalling. This confirms earlier results and extends them to large particle numbers and rotating systems. We find that the SMBHB hardening depends on the binary-reduced mass ratio via a single parameter function. Our results suggest that, at a fixed value for the SMBHB primary mass, the merger time of highly asymmetric binaries is up to four order of magnitudes smaller than the equal-mass binaries. This can significantly affect the population of SMBHs potentially detectable as gravitational wave sources.