Short gamma-ray bursts within 200 Mpc. Issue 4 (16th January 2020)

• Record Type: Journal Article
• Authors: Dichiara, S; Troja, E; O'Connor, B; Marshall, F E; Beniamini, P; Cannizzo, J K; Lien, A Y; Sakamoto, T
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 492:Issue 4(2020)
• Page Start: 5011
• Page End: 5022
• Publication Date: 2020-01-16
• Subjects: gravitational waves -- nuclear reactions, nucleosynthesis, abundances -- stars: neutron -- gamma-ray bursts; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/staa124
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We present a systematic search for short-duration gamma-ray bursts (GRBs) in the local Universe based on 14 yr of observations with the Neil Gehrels Swift Observatory . We cross-correlate the GRB positions with the GLADE catalogue of nearby galaxies, and find no event at a distance ≲100 Mpc and four plausible candidates in the range 100 Mpc ≲ D ≲ 200 Mpc. Although affected by low statistics, this number is higher than the one expected for chance alignments to random galaxies, and possibly suggests a physical association between these bursts and nearby galaxies. By assuming a local origin, we use these events to constrain the range of properties for X-ray counterparts of neutron star mergers. Optical upper limits place tight constraints on the onset of a blue kilonova, and imply either low masses ($\lesssim 10^{-3}\, \mathrm{M}_{\odot }$ ) of lanthanide-poor ejecta or unfavorable orientations (θobs ≳ 30 deg). Finally, we derive that the all-sky rate of detectable short GRBs within 200 Mpc is $1.3^{+1.7}_{-0.8}$ yr −1 (68 per cent confidence interval), and discuss the implications for the GRB outflow structure. If these candidates are instead of cosmological origin, we set a upper limit of ≲2.0 yr −1 (90 per cent confidence interval) to the rate of nearby events detectable with operating gamma-ray observatories, such as Swift and Fermi .