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GCN Circular 4593

GRB 060124: Keck optical spectrum
2006-01-25T10:09:22Z (18 years ago)
Jason Prochaska at UCO/Lick Obs <>
J. X. Prochaska (UCO-Lick/UCSC),  R. Foley (UCB),
H. Tran (Keck), J. S. Bloom (UCB), H.-W. Chen (MIT),
report on behalf of the GRAASP collaboration:

"We have obtained Keck/LRIS spectra of the afterglow
of GRB 060124 starting at UT Jan 25 07:15 in polarimetry
mode under poor observing conditions.   We confirm the absorption
features at ~5105A reported by Mirabal et al. (GCN 4591)
and rule out MgII on the basis of their separation.
Instead, we identify these features as CIV corresponding to
z=2.296 and we note a weak absorption feature consistent with
this redshift corresponding to AlII 1670.  We also
identify an absorption line at ~4000Ang consistent with
Lya absorption and indicating log N(HI) < 20.5.

Although we may also detect a weak feature consistent with
SiII 1526 at 5030Ang, this afterglow spectrum is notable
for exhibiting very weak low-ion features (e.g. non-detections
of FeII 1608, OI 1302, CII 1334) and relatively low HI column density.
In this respect the spectrum is similar to the afterglows
of GRB 050908 and GRB 021004.

Finally, we note a strong absorption feature at ~4840Ang
which could be MgII at z=0.73.

We thank the Keck Observatory for acquiring these observations
during Director's discretionary time.  The data will be made
publically available at"

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