GRB 060927.589: Spectroscopic redshift z=5.6

GRB 060927.589: Spectroscopic redshift z=5.6

Click for larger image

LEFT: Finding chart for GRB 060927.589
Acquisition image from VLT+FORS1. The circle indicates the refined XRT localisation (Troja et al., GCN #5641). The lines indicate the position of the optical afterglow from the Faulkes Telescope South (Guidorzi et al., GCN #5633).

RIGHT: 2-d spectrum
The spectrum shows the continuum break at 8070 Å. The two upper traces are from other objects on the slit. The lower trace is for the source at the afterglow position.

NUMBER:  5651
SUBJECT: GRB060927: Spectroscopic redshift z=5.6
DATE:    06/09/29

Johan P. U. Fynbo (DARK Cosmology Centre), Pall Jakobsson (U. of Hertfordshire), Brian L. Jensen, Jens Hjorth, Jesper Sollerman, Darach Watson, José María Castro Cerón (DARK Cosmology Centre), Paul Vreeswijk (ESO), Michael I. Andersen (Potsdam) report on behalf of a larger collaboration:

"Using FORS1 on the ESO Very Large Telescope we obtained a 3x30min spectrum of the afterglow of GRB 060927 (GCNs #5627, 5629) on Sep 28.1. We detect a sharp continuum break at 8070 A which we interpret as the onset of the Lyman-alpha forest. Hence the redshift of GRB 060927 is z=5.6.

We have placed a finding chart and an image of the 2d-spectrum here: http://www.astro.ku.dk/~brian_j/grb/grb060927.589/

We thank the Paranal staff for excellent support."

Last updated on September 29, 2006, by Brian Lindgren Jensen