GRB 971214
ATel #7; S. R. Kulkarni, K. L. Adelberger, J. S. Bloom, T. Kundic, L. Lubin, (California Institute of Technology)
on 24 Jan 1998; 04:07 UT
Credential Certification: rutledge@rosat.mpe-garching.mpg.de
Subjects: Optical, Gamma-Ray Burst
On December 28, 1997, Kundic and Lubin obtained spectra of the optical
transient of GRB 971214 (IAUC # 6788 ) with the Low Resolution Imaging
Spectrograph (LRIS) mounted on the Keck II telescope. The seeing
conditions were excellent. If the transient continued the power-law
decay as indicated by the data from Halpern et al. (IAUC # 6788 ) then
by this epoch the light at this position should be dominated by the
host (cf. Kulkarni et al. GCN #27; ATEL #5). Analysis of these
spectra show a slightly extended emission feature at 5384 A.
Additionally, a broad absorption feature is seen at 5752 A. We cannot
at this time make a definitive statement about the redshift of the
host. If, the emission feature is identified as Lyman-alpha and the
absorption feature as OI 1302 A then the redshift of the (presumed)
host is z=3.43. However, there appears to be no obvious depression
bluewards of this feature as is normally seen in high-redshift objects
(caused by the Lyman forest). If, however, the emission feature is
identified with the [OII] 3727 line then the redshift is z=0.44.
A strong emission feature at a wavelength of 5602 A is also seen
in the spectrum of the nearby galaxy G1 (GCN #12; GCN
#13). Identifying this as the [OII] 3727 A feature as well as matching
major absorption features yields a redshift of z=0.50.
We are in the process of analyzing additional LRIS data to improve
the signal-to-noise ratio and also to understand the apparent
discrepancy with similar data obtained on 17 Dec 1997 UT (GCN #12).
We note that the earlier data were obtained under bright lunar
conditions while the data reported herein was obtained during dark
time.
This message is citable.
