Accretion of clumpy cold gas onto massive black hole binaries: A possible fast route to binary coalescence

Felipe G. Goicovic, Cristián Maureira-Fredes, Alberto Sesana, Pau Amaro-Seoane, Jorge Cuadra

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


In currently favoured hierarchical cosmologies, the formation of massive black hole binaries (MBHBs) following galaxy mergers is unavoidable. Still, due the complex physics governing the (hydro)dynamics of the post-merger dense environment of stars and gas in galactic nuclei, the final fate of those MBHBs is still unclear. In gas-rich environments, it is plausible that turbulence and gravitational instabilities feed gas to the nucleus in the form of a series of cold incoherent clumps, thus providing a way to exchange energy and angular momentum between the MBHB and its surroundings.Within this context, we present a suite of smoothed-particlehydrodynamical models to study the evolution of a sequence of near-radial turbulent gas clouds as they infall towards equal-mass, circular MBHBs.We focus on the dynamical response of the binary orbit to different levels of anisotropy of the incoherent accretion events. Compared to a model extrapolated from a set of individual cloud-MBHB interactions, we find that accretion increases considerably and the binary evolution is faster. This occurs because the continuous infall of clouds drags inwards circumbinary gas left behind by previous accretion events, thus promoting a more effective exchange of angular momentum between the MBHB and the gas. These results suggest that sub-parsec MBHBs efficiently evolve towards coalescence during the interaction with a sequence of individual gas pockets.

Original languageEnglish
Pages (from-to)3438-3455
Number of pages18
JournalMonthly Notices of the Royal Astronomical Society
Issue number3
StatePublished - 21 Sep 2018
Externally publishedYes


  • Accretion, accretion discs
  • Black hole physics
  • Galaxies: evolution
  • Galaxies: nuclei
  • Hydrodynamics


Dive into the research topics of 'Accretion of clumpy cold gas onto massive black hole binaries: A possible fast route to binary coalescence'. Together they form a unique fingerprint.

Cite this