GCN Circular 6498
Subject
GRB 060121 : pseudo-z = 1.9 ('intermediate-duration' burst)
Date
2007-06-11T08:00:09Z (17 years ago)
From
Alexandre Pelangeon at LATT,OMP,Toulouse <alexandre.pelangeon@ast.obs-mip.fr>
A. Pelangeon & J-L. Atteia (LATT-OMP) report:
We have used the spectral parameters of GRB 060121 detected by
HETE-2/FREGATE
and localized by the WXM (Arimoto et al., GCNC 4550) and by the SXC
(Prighozin et al., GCNC 4551) to compute the spectral pseudo-redshift(**)
of this burst.
We find a pseudo-redshift pz = 1.92 � 0.35
This value is in agreement with the lowest of the two values derived
by de Ugarte-Postigo et al. for the photometric redshift
of the host-galaxy: z = 1.7 � 0.4, and z = 4.6 � 0.5 (ApJ, 2006, 648, L83)
This pseudo-redshift relies on the assumption that GRB 060121 follows
the Amati relation. Hence we caution that if GRB 060121 is a short burst,
as suggested by Donaghy et al. (astro-ph/0605570), this pseudo-redshift
is not reliable.
(**) cf. http://www.ast.obs-mip.fr/grb/pz