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GCN Circular 249

GRB 990123 NOT Spectrum Update
1999-02-03T22:46:15Z (25 years ago)
Jens Hjorth at U.Copenhagen <>
GRB 990123 NOT Spectrum Update

J. Hjorth (Copenhagen), M. I. Andersen (NOT), H. Pedersen (Copenhagen), 
M. R. Zapatero-Osorio (IAC), E. Perez (IAA) and 
A. J. Castro Tirado (LAEFF, IAA) report:

"We have conducted an improved analysis of the NOT spectra reported in 
GCN #219. We detect several absorption lines in addition to the ones found 
in the preliminary analysis, including Al III (185.5 and 186.3 nm). The 
suggested assignment of two significant absorption lines with Zn II (202.6 
and 206.3 nm) is uncertain. The resulting updated redshift is 1.598 +- 0.001. 
The detection of an emission line associated with a system at z = 0.286 is not 
confirmed. This considerably reduces the significance of the proposed line 
system at z = 0.286. The significance of the line system at z = 0.21 is 
unchanged and its reality remains uncertain. These findings are consistent 
with the Keck results (IAUC #7096; GCN #223; GCN #235). The orientation of the 
slit during the observations was along the parallactic angle (roughly E-W) and 
covered the galaxy ~10" to the W of GRB 990123. The redshift of this galaxy is 
0.278 +- 0.001 based on Ca II K and H (393.3 nm and 396.9 nm), G band 
(400.3 nm) and Mgb (517.4 nm)."
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