GCN Circular 4974

Paul Vreeswijk (U. of Chile/ESO) and Andreas Jaunsen (U. of Oslo)
report on behalf of a larger collaboration:

"Following the Swift detection of GRB060418 (Falcone et al., GCN
4966
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 ), we triggered observations with the Ultraviolet and Visual
Echelle Spectrograph (UVES), mounted at Kueyen (UT2) of ESO's Very
Large Telescope (VLT). The observations were performed using the
Rapid-Response Mode, which allows for robotic VLT observations without
any human intervention, except for the slit alignment. Starting at
3:16 UT (10min after the Swift/BAT trigger), a series of exposures
with increasing integration times (3, 5, 10, 20, and 40min) were
performed with central wavelengths 390nm in the blue arm and 564nm in
the red, covering 330-670nm at a resolving power of ~43000. This was
followed by a 90min exposure with central wavelengths 437nm in the
blue and 860nm in the red, extending the wavelength coverage up to
950nm.

A preliminary analysis of the spectra shows various absorption
features, which can be identified with typical metal lines originating
in at least four intervening absorbers at redshifts: z=0.602, z=0.655,
z=1.106 and the highest at z=1.489. This confirms the GRB060418
host-galaxy redshift determination by Dupree et al. (GCN 4969
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 ).

We are very grateful for the excellent support of the Paranal staff,
and in particular that of Stefano Bagnulo, Nancy Ageorges and Stan
Stefl."