{
  "id": "2108.04250",
  "version": "v1",
  "published": "2021-08-09T18:00:02.000Z",
  "updated": "2021-08-09T18:00:02.000Z",
  "title": "Merger rate density of stellar-mass binary black holes from young massive clusters, open clusters, and isolated binaries: comparisons with LIGO-Virgo-KAGRA results",
  "authors": [
    "Sambaran Banerjee"
  ],
  "comment": "20 pages, 12 figures. Comments are welcome",
  "categories": [
    "astro-ph.HE",
    "astro-ph.GA"
  ],
  "abstract": "I investigate the roles of cluster dynamics and massive binary evolution in producing stellar-remnant binary black hole (BBH) mergers over the cosmic time. To that end, dynamical BBH mergers are obtained from long-term direct N-body evolutionary models of $\\sim10^4M_\\odot$, pc-scale young massive clusters (YMC) evolving into moderate-mass open clusters (OC). Fast evolutionary models of massive isolated binaries (IB) yield BBHs from binary evolution. Population synthesis in a Model Universe is then performed, taking into account observed cosmic star-formation and enrichment histories, to obtain BBH-merger yields from these two channels observable at the present day and over cosmic time. The merging BBH populations from the two channels are combined by applying a proof-of-concept Bayesian regression chain, taking into account observed differential intrinsic BBH merger rate densities from the second gravitational-wave transient catalogue (GWTC-2). The analysis estimates an OB-star binary fraction of $f_{\\rm Obin}\\gtrsim60$% and a YMC formation efficiency of $f_{\\rm YMC}\\sim10^{-2}$, being consistent with recent optical observations and large scale structure formation simulations. The corresponding combined Model Universe present-day, differential intrinsic BBH merger rate density and the cosmic evolution of BBH merger rate density both agree well with those from GWTC-2. The analysis also suggests that despite significant 'dynamical mixing' at low redshifts, BBH mergers at high redshifts ($z_{\\rm event}\\gtrsim1$) could still be predominantly determined by binary-evolution physics. Caveats in the present approach and future improvements are discussed.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2021-08-09T18:00:02.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "stellar-mass binary black holes",
      "young massive clusters",
      "intrinsic bbh merger rate density",
      "differential intrinsic bbh merger rate",
      "open clusters"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 20,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}