GCN Circular 3424
Subject
GRB 050509B and short GRB-SN association? (corrected)
Date
2005-05-15T11:13:06Z (20 years ago)
From
Arnon Dar at Technion-Israel Inst. of Tech <arnon@physics.technion.ac.il>
S. Dado (Technion), A. Dar (Technion) and A. De Rujula (CERN) report:
The leading scenarios for the production of short-duration GRBs involve
(a) neutron-star mergers [1] (b) super flares from SGRs (GCN 2942 and [2])
(c) gravitational collapse of neutron stars to strange-quark stars [3] (d)
gravitational collapse of C/O white dwarfs to neutron stars (GCN 2174 and
[4]). While scenarios (a), (b) are not associated with standard optical
supernovae (SNe), scenarios (c),(d) are expected to produce a standard
optical SN. In particular, in scenario (d), a Type Ia SN is expected at the
GRB location with standard rest-frame optical light curves peaking around
20 days after burst with un-reddened absolute magnitudes [5] Bmax ~ -19.47,
Vmax ~ - 19.42, Rmax ~ - 19.42 and Imax ~ - 19.06 (+\-0.15).
GRB050509B (GCN 3381) is the first well-localized short-duration (~ 30 ms)
GRB. A SN associated with a short GRB has never been looked for
in such favorable conditions.
In the observer's frame the associated-SN expected un-reddened spectral
energy density at a frequency nu and a time t after burst is:
F(nu,t) = F'(nu',t') [1+z] [D(z')]^2 / ( [1+z'] [D(z)]^2] )
where z' is the redshift of a template Type Ia SN with spectral energy
density F'; D(z) and D(z') are luminosity distances, nu'=[(1+z)/(1+z')] nu
and t'=[(1+z')/(1+z)] t.
If GRB050509B was produced in association with a Type Ia SN in the galaxy
cluster NSC J123610+28590, at redshift z = 0.225 (GCN 3390), its rising
optical light curve should be observable well before its peak around t =
25 days after burst with Vmax ~ 20.43 +/- 0.15 (extinction in the host
galaxy is not included, but Galactic extinction in the direction of GRB
050509B, Av~0.06 [6] is included).
In spite of the non-detections of an optical afterglow near the refined
XRT error circle (GCN 3395) of GRB 050509B, a SN search in this direction,
perhaps with telescopes such as Keck, VLT, Subaru and HST, may prove
very fruitful.
[1] Goodman, J., Dar, A., & Nussinov, S. 1987, ApJ, 314, L7
[2] Hurley, K., et al. 2005, astro-ph/0502329
[3] Dar, A. 1999, A&AS, 138, 505
[4] Dar, A. & De Rujula, A. 2004, Physics Reports, 405, 203
[5] Germany, L. M., et al. 2004, A&A 415, 863
[6] Schlegel, D. J.; Finkbeiner, D. P. & Davis, M. 1998, ApJ, 500, 525