Evidence for a dual population of neutron star mergers from short Gamma-Ray Burst observations

Abstract

Short duration Gamma-Ray Bursts are thought to originate from the coalescence of neutron stars in binary systems. They are detected as a brief ($<$ 2s), intense flash of gamma-ray radiation followed by a weaker, rapidly decreasing afterglow. They are expected to be detected by Advanced LIGO and Virgo when their sensitivity will be low enough. In a recent study we identified a population of short Gamma-Ray Bursts that are intrinsically faint and nearby. Here we provide evidence in favor of the existence of this new population that can hardly be reproduced with a model of field neutron star binary coalescences. We propose that these systems may be produced dynamically in globular clusters, and may result from the merger of a black hole and a neutron star. The advanced LIGO and Virgo observation of a high rate of NSBH mergers compatible with the dynamical formation in globular clusters would be a confirmation of this hypothesis and would enable for the derivation of the mass function of black holes inside globular clusters, as well as the luminosity function of faint short GRBs.

arXiv comment15 pages, 5 figures, 1 table, submitted to ApJ

References in corpus (3)

• The Rate of Binary Black Hole Mergers Inferred from Advanced LIGO Observations Surrounding GW150914
• Fermi GBM Observations of LIGO Gravitational Wave event GW150914
• Dynamical Formation of the GW150914 Binary Black Hole

Cited by in corpus (10)

• Gravitational Waves and Gamma-rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A
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• Search for Gravitational Waves Associated with Gamma-Ray Bursts During the First Advanced LIGO Observing Run and Implications for the Origin of GRB 150906B
• A comprehensive statistical study on gamma-ray bursts
• Jet Geometry and Rate Estimate of Coincident Gamma Ray Burst and Gravitational Wave Observations
• Multimessenger astronomy with a kHz-band gravitational-wave observatory
• Transient Survey Rates for Orphan Afterglows from Compact Merger Jets
• An optical search for transients lasting a few seconds
• Possible correlations between gamma-ray burst and its host galaxy offset
• The apparent and cosmic rates of short gamma-ray bursts