GRB 060121: Implications of a Short/Intermediate Duration Gamma-Ray Burst at High Redshift

Abstract

Since the discovery of the first short-hard gamma-ray burst afterglows in 2005, the handful of observed events have been found to be embedded in nearby (z < 1), bright underlying galaxies. We present multiwavelength observations of the short-duration burst GRB 060121, which is the first observed to clearly outshine its host galaxy (by a factor >10^2). A photometric redshift for this event places the progenitor at a most probable redshift of z = 4.6, with a less probable scenario of z = 1.7. In either case, GRB 060121 could be the farthermost short-duration GRB detected to date and implies an isotropic-equivalent energy release in gamma-rays comparable to that seen in long-duration bursts. We discuss the implications of the released energy on the nature of the progenitor. These results suggest that GRB 060121 may belong to a family of energetic short-duration events, lying at z > 1 and whose optical afterglows would outshine their host galaxies, unlike the first short-duration GRBs observed in 2005. The possibility of GRB 060121 being an intermediate duration burst is also discussed.

4 pages, 4 figures. Submitted to ApJL

References in corpus (3)

• Galaxies in the Hubble Ultra Deep Field: I. Detection, Multiband Photometry, Photometric Redshifts, and Morphology
• A new definition of the intermediate group of gamma-ray bursts
• The faint afterglow and host galaxy of the short-hard GRB 060121

Cited by in corpus (14)

• Discerning the physical origins of cosmological Gamma-ray bursts based on multiple observational criteria: the cases of z=6.7 GRB 080913, z=8.3 GRB 090423, and some short/hard GRBs
• The Konus-Wind catalog of gamma-ray bursts with known redshifts. I. Bursts detected in the triggered mode
• Different progenitors of short hard gamma-ray bursts
• Gamma-ray burst progenitors
• The optical afterglows and host galaxies of three short/hard gamma-ray bursts
• The Early-time Optical Properties of Gamma-Ray Burst Afterglows
• The Prompt Gamma-Ray and Afterglow Energies of Short-Duration Gamma-Ray Bursts
• Multicolor observations of the afterglow of the short/hard GRB 050724
• Short Gamma Ray Bursts: a bimodal origin?
• On the nature of the short duration GRB 050906
• Extensive multiband study of the X-ray rich GRB 050408. A likely off-axis event with an intense energy injection
• GRB 221009A: An ordinary nearby GRB with extraordinary observational properties
• Constraints on an optical afterglow and on supernova light following the short burst GRB 050813
• Optical darkness in short-duration $\gamma$-ray bursts