Constraining the fraction of binary black holes formed in isolation and young star clusters with gravitational-wave data

Research output: Contribution to journalArticlepeer-review


  • Yann Bouffanais
  • Michela Mapelli
  • Ugo N. Di Carlo
  • Nicola Giacobbo
  • Emanuele Berti
  • Vishal Baibhav

Colleges, School and Institutes


Ten binary black hole mergers have already been detected during the first two observing runs of advanced LIGO and Virgo, and many more are expected to be observed in the near future. This opens the possibility for gravitational-wave (GW) astronomy to better constrain the properties of black hole binaries—not only as single sources, but as a whole astrophysical population. In this paper, we address the problem of using GW measurements to estimate the proportion of merging black holes produced either via isolated binaries or binaries evolving in young star clusters. To this end, we use a Bayesian hierarchical modeling approach applied to catalogs of merging binary black holes generated using state-of-the-art population synthesis and N-body codes. In particular, we show that, although current advanced LIGO/Virgo observations only mildly constrain the mixing fraction {f}\in [0,1] between the two formation channels, we expect to narrow down the fractional errors on {f} to 10%─20% after a few hundreds of detections....


Original languageEnglish
Number of pages13
JournalThe Astrophysical Journal
Issue number1
Publication statusPublished - 15 Nov 2019


  • black hole physics, gravitational waves, methods: statistical