On the offset of Short Gamma-ray Bursts

Abstract

Short Gamma-Ray Bursts (SGRBs) are expected to form from the coalescence of compact binaries, either of primordial origin or from dynamical interactions in globular clusters. In this paper, we investigate the possibility that the offset and afterglow brightness of a SGRB can help revealing the origin of its progenitor binary. We find that a SGRB is likely to result from the primordial channel if it is observed within 10 kpc from the center of a massive galaxy and shows a detectable afterglow. The same conclusion holds if it is 100 kpc away from a small, isolated galaxy and shows a weak afterglow. On the other hand, a dynamical origin is suggested for those SGRBs with observable afterglow either at a large separation from a massive, isolated galaxy or with an offset of 10-100 kpc from a small, isolated galaxy. We discuss the possibility that SGRBs from the dynamical channel are hosted in intra-cluster globular clusters and find that GRB 061201 may fall within this scenario.

5 pages, 3 figures, MNRAS in press

References in corpus (15)

• The ACS Virgo Cluster Survey. XII. The Luminosity Function of Globular Clusters in Early Type Galaxies
• Hubble Space Telescope Observations of Short GRB Host Galaxies: Morphologies, Offsets, and Local Environments
• The Host Galaxies of Short-Duration Gamma-Ray Bursts: Luminosities, Metallicities, and Star Formation Rates
• Different progenitors of short hard gamma-ray bursts
• Spatially resolved properties of the GRB 060505 host: implications for the nature of the progenitor
• On the consistency of the peculiar GRBs 060218 and 060614 with the Ep,i - Eiso correlation
• GRB 090426: The Environment of a Rest-Frame 0.35-second Gamma-Ray Burst at Redshift z=2.609
• GRB090426: the farthest short gamma-ray burst?
• The optical afterglows and host galaxies of three short/hard gamma-ray bursts
• The Spectral Lag of GRB060505: A Likely Member of the Long Duration Class
• The short GRB070707 afterglow and its very faint host galaxy
• Short Gamma Ray Bursts: a bimodal origin?
• On spatial distributions of old globular clusters in clusters of galaxies
• The Host Galaxy of GRB 060505: Host ISM Properties
• Intracluster Short Gamma-Ray Bursts by Compact Binary Mergers

Cited by in corpus (4)

• A Jet Break in the X-ray Light Curve of Short GRB 111020A: Implications for Energetics and Rates
• Identifying the Location in the Host Galaxy of the Short GRB 111117A with the Chandra Sub-arcsecond Position
• A history of the gamma-ray burst flux at the Earth from Galactic globular clusters
• Possible correlations between the emission properties of short GRBs and their offsets from the host galaxies