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Title: NUCLEOSYNTHESIS CONSTRAINTS ON THE NEUTRON STAR-BLACK HOLE MERGER RATE

We derive constraints on the time-averaged event rate of neutron star-black hole (NS-BH) mergers by using estimates of the population-integrated production of heavy rapid neutron-capture (r-process) elements with nuclear mass numbers A > 140 by such events in comparison to the Galactic repository of these chemical species. Our estimates are based on relativistic hydrodynamical simulations convolved with theoretical predictions of the binary population. This allows us to determine a strict upper limit of the average NS-BH merger rate of ∼6× 10{sup –5} per year. We quantify the uncertainties of this estimate to be within factors of a few mostly because of the unknown BH spin distribution of such systems, the uncertain equation of state of NS matter, and possible errors in the Galactic content of r-process material. Our approach implies a correlation between the merger rates of NS-BH binaries and of double NS systems. Predictions of the detection rate of gravitational-wave signals from such compact object binaries by Advanced LIGO and Advanced Virgo on the optimistic side are incompatible with the constraints set by our analysis.
Authors:
 [1] ; ;  [2] ;  [3]
  1. Department of Physics, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece)
  2. Max Planck Institute for Astrophysics, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany)
  3. Institut d'Astronomie et d'Astrophysique, Université Libre de Bruxelles, C.P. 226, B-1050 Brussels (Belgium)
Publication Date:
OSTI Identifier:
22364573
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 795; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BLACK HOLES; CAPTURE; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; CORRELATIONS; EQUATIONS OF STATE; GRAVITATIONAL WAVES; HYDRODYNAMICS; LIMITING VALUES; NEUTRON REACTIONS; NEUTRON STARS; NEUTRONS; NUCLEOSYNTHESIS; R PROCESS; RELATIVISTIC RANGE; SPIN