GCN Circular 18263
Subject
Short GRB 150906B: proximity to NGC 3313 galaxy group
Event
Date
2015-09-09T08:45:20Z (10 years ago)
From
Nial Tanvir at U.Leicester <nrt3@star.le.ac.uk>
A. J. Levan (U. Warwick), N. R. Tanvir (U. Leicester) and J. Hjorth (DARK/NBI) report:
We note that the preliminary IPN localisation of the short, intense GRB 150906B (Hurley et al. GCN 18258, Golenetskii et al. GCN 18259) lies close to the local galaxy NGC 3313 (z=0.0124, d=54 Mpc). At its closest the IPN error box passes approximately 8.5 arc minutes from the centre of the galaxy, which has a major diameter of 4 arc minutes. This offset corresponds to approximately 130 kpc in projection at 54 Mpc, and is within the range that either kicked neutron star binaries or globular clusters associated with NGC 3313 may be found. In fact, NGC 3313 is the brightest galaxy of a moderate group, and there are several other fainter group members (presumably with shallower potential wells and hence greater typical binary neutron star kick offsets) that lie comparably close to the IPN error region, which are thus also candidate hosts. An image showing the IPN region and group members is at http://www.star.le.ac.uk/~nrt3/NGC3313_group.png .
At 54 Mpc the inferred isotropic energy of GRB 150906B would be E_iso ~ 10^49 erg, within the range of energetics of known short-GRBs.
Although it is certainly plausible that the proximity of GRB 150906B to NGC 3313 is a chance alignment, it is of particular interest given that NGC 3313 lies well within the expected detection horizon of Advanced-LIGO/VIRGO for compact binary mergers. Unfortunately the sky location of GRB 150906B means that it is very poorly placed for optical/IR observations at this time.