Short gamma-ray burst progenitors have short delay times
Reviewed by Pith T0 review T1 audit T2 compute T3 formal T4 kernel pith:HJPKZRZ4record.jsonopen to challenge →
read the original abstract
Short gamma-ray bursts (SGRBs) are thought to be primarily associated with binary neutron star (BNS) mergers. The SGRB population can therefore be scrutinized to look for signatures of the delay time between the formation of the progenitor massive star binary and the eventual merger, which could produce an evolution of the cosmic rate density of such events whose shape departs from that of the cosmic star formation history (CSFH). To that purpose, we study a large sample of SGRBs within a hierarchical Bayesian framework, with a particular focus on the delay time distribution (DTD) of the population. Following previous studies, we model the DTD either as a power-law with a minimum time delay or as a log-normal function. We consider two models for the intrinsic SGRB luminosity distribution: an empirical luminosity function (ELF) with a doubly broken power-law shape, and one based on a quasi-universal structured jet (QUSJ) model. Regardless of the chosen parametrization, we find average time delays $10\lesssim \langle \tau_\mathrm{d}\mathrm\rangle/\mathrm{Myr}\lesssim 800$ and a minimum delay time $\tau_\mathrm{d,min}\lesssim 350\,\mathrm{Myr}$, in contrast with previous studies that found long delay times of few Gyr. We demonstrate that the cause of the longer inferred time delays in past studies most likely resides in an incorrect treatment of selection effects.
This paper has not been read by Pith yet.
Forward citations
Cited by 5 Pith papers
-
Binary Neutron Star Merger Evolution and r-Process Enrichment in the Milky Way Disk
Binary neutron star mergers with evolving merger rates or yields are strongly preferred over constant scenarios to explain Milky Way r-process enrichment, with Bayes factors exceeding 10^20, yet remain in tension with...
-
Double Neutron Star Delay Times Across Cosmic Metallicities: The Role of Helium Star Progenitors
Simulations show double neutron star mergers peak 80-250 million years after star formation across metallicities, with 15% quick mergers and over 20% delayed over a billion years.
-
Double Neutron Star Delay Times Across Cosmic Metallicities: The Role of Helium Star Progenitors
Population synthesis of helium star-NS systems yields DNS delay time distributions that peak between 80-250 Myr across metallicities, with 15% merging within 80 Myr and over 20% after 1 Gyr.
-
Implications of low neutron star merger rates for gamma-ray bursts, r-process production and Galactic double neutron stars
Lower BNS merger rates from GWTC-4 data produce tensions of factors 3.6-18 with SGRB rates, 0.9-4.1 with r-process rates, and 2.3-5.1 with Galactic DNS rates.
-
Wide Jets or Low Rates: Reconciling Short GRB and Gravitational-Wave Neutron Star Merger Rates
Latest GW neutron star merger rates are consistent with short GRBs being produced by BNS mergers if jets are wide or rates low, with NSBH mergers subdominant.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.