GCN Circular 5982

J. P. Halpern & N. Mirabal (Columbia U.) report on behalf of the
MDM Observatory GRB follow-up team:

"Previously, we reported the detection of the optical afterglow of
Swift GRB 050826 within a relatively bright, irregular galaxy of
R=21.67, or R=20.1 when corrected for Galactic extinction.
Image subtraction was used to separate the OT contribution
from the host galaxy. See GCNs 3891
Not found
 
 
 and 4749
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 for details.

On 2006 Dec. 24 UT, we obtained three 1-hour, low-resolution spectra
of the host galaxy using the Boller & Chivens CCD Spectrograph (CCDS)
on the MDM 2.4m telescope.  Acquisition was by blind offset. Narrow
emission lines corresponding to [O II] 3727 and [O III] 4959,5007
are seen in the individual exposures.  Their line strengths are
characteristic of a high-excitation starburst, similar to other
hosts of long bursts.  From the summed spectrum, we derive a redshift
of z=0.297+/-0.001.

The Swift BAT fluence of 4.3x10^-7 erg/cm^2 in the 15-150 keV band
(Markwardt et al., GCN 3888
Not found
 
 
) then corresponds to an isotropic
energy release of 9x10^49 erg using standard cosmological parameters.
This example illustrates the role of image subtraction in completing
the census of low-luminosity GRBs in nearby galaxies.

This message may be cited."