{
  "bibcode": "2010GCN.10441....1G",
  "body": "P. Groot (Radboud Univ. Nijmegen), L. Kaper, L. Ellerbroek (Univ. \nAmsterdam), D. Malesani (DARK/NBI), P. Jakobsson (Univ. Iceland), J. P. \nU. Fynbo, J. Hjorth, D. J. Watson (DARK/NBI), and E. Mason (ESO), report \non behalf of a larger collaboration:\n\nWe observed the optical objects associated to GRB 100219A (Rowlinson et \nal., GCN 10430; Holland & Rowlinson, GCN 10432; Bloom & Nugent, GCN \n10433; Jakobsson et al., GCN 10438; Kruehler et al., GCN 10439) with the \nVLT equipped with the X-shooter spectrograph. The slit was oriented so \nto include both the pre-existing object and the candidate afterglow. \nObservations started on 2010 Feb 20.105 UT (0.47 days after the GRB), \nfor a total exposure time of 4x1200 s.\n\nIn a preliminary analysis of the spectra, we detect a clear signal from \nboth objects. The continuum from the candidate afterglow is only \ndetected redward of ~5310 AA. A further spectral break is recognised at \n~7060 AA. This is consistent with the onset of the Lyman limits and of \nthe Lyman alpha forest at a common redshift z = 4.8. Our observations \nare consistent with the photometric redshift indicated by the GROND \nobservations (Kruehler et al., GCN 10439).\n\nThe high luminosity of the object and its spectral shape indicate that \nthis is indeed the afterglow of GRB 100219A.\n\nThe spectrum of the nearby galaxy implies a significantly lower \nredshift, around z=0.25, hence it is unrelated to the GRB.\n\nWe caution that the above analysis (particularly the wavelength \nsolution) is preliminary. Reduction with updated calibrations is \nunderway. We would like to thank Alain Smette (ESO) for his kind assistance.",
  "circularId": 10441,
  "createdOn": 1266641334000,
  "email": "malesani@dark-cosmology.dk",
  "subject": "GRB 100219A: VLT/X-shooter redshift",
  "submitter": "Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>",
  "eventId": "GRB 100219A"
}