Nuclear coups: dynamics of black holes in galaxy mergers - INSU - Institut national des sciences de l'Univers Access content directly
Journal Articles Monthly Notices of the Royal Astronomical Society Year : 2014

Nuclear coups: dynamics of black holes in galaxy mergers

Sandor van Wassenhove
  • Function : Author
Pedro R. Capelo
  • Function : Author
Marta Volonteri
Massimo Dotti
  • Function : Author
Jillian M. Bellovary
  • Function : Author
Lucio Mayer
  • Function : Author
Fabio Governato
  • Function : Author


We study the dynamical evolution of supermassive black holes (BHs) in merging galaxies on scales of hundreds of kpc to 10 pc, to identify the physical processes that aid or hinder the orbital decay of BHs. We present hydrodynamical simulations of galaxy mergers with a resolution of ≤20 pc, chosen to accurately track the motion of the nuclei and provide a realistic environment for the evolution of the BHs. We find that, during the late stages of the merger, tidal shocks inject energy in the nuclei, causing one or both nuclei to be disrupted and leaving their BH `naked', without any bound gas or stars. In many cases, the nucleus that is ultimately disrupted is that of the larger galaxy (`nuclear coup'), as star formation grows a denser nuclear cusp in the smaller galaxy. We supplement our simulations with an analytical estimate of the orbital-decay time required for the BHs to form a binary at unresolved scales, due to dynamical friction. We find that, when a nuclear coup occurs, the time-scale is much shorter than when the secondary's nucleus is disrupted, as the infalling BH is more massive, and it also finds itself in a denser stellar environment.
Fichier principal
Vignette du fichier
stu024.pdf (2.86 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

insu-03645686 , version 1 (22-04-2022)



Sandor van Wassenhove, Pedro R. Capelo, Marta Volonteri, Massimo Dotti, Jillian M. Bellovary, et al.. Nuclear coups: dynamics of black holes in galaxy mergers. Monthly Notices of the Royal Astronomical Society, 2014, 439, pp.474-487. ⟨10.1093/mnras/stu024⟩. ⟨insu-03645686⟩
12 View
6 Download



Gmail Facebook Twitter LinkedIn More