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GCN Circular 3679

GRB 050724: GMOS Imaging and Spectroscopy
2005-07-26T00:44:54Z (19 years ago)
Jason Prochaska at UCO/Lick Obs <>
J.X. Prochaska (UCO/Lick), H.-W. Chen (MIT), J.S. Bloom (UCB),
and A. Stephens (Gemini) report on behalf of the GRAASP

We have obtained GMOS/R400 spectroscopy (2400s) of the Sources
identified as A, B and D in GCN #3672.  We confirm
the identification of Source B as a Galactic star
(GCN #3675).  We tentatively identify Source A as a
Galactic star based on its PSF and featureless spectrum.

Our acquisition image of the field clearly demonstrates
that Source D is extended and therefore a galaxy.  Our
spectrum of the galaxy is nearly featureless
(lambda=5000-9000A), indicating the galaxy is an early
type consistent with its red color (GCN #3673).
We assign a possible redshift of z=0.257 based on
absorption features at ~6510A and ~7415A which we
associate with MgI and NaI.  The galaxy is located
7.2" from the refined XRT position (GCN #3678) which
would correspond to 27kpc at z=0.257.

Further observations are encouraged.

We thank the Gemini staff for their help in acquiring
this dataset.

Plots of the data can be found here:

Jason X. Prochaska
UCO/Lick Observatory
UC Santa Cruz
Santa Cruz, CA 95064
831-459-2135 (Direct)
831-459-2991 (UCO/Lick Main)
831-459-5244 (Fax)
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