{
  "bibcode": "2010GCN.11164....1C",
  "body": "R. Chornock, E. Berger (Harvard), D. Fox (Penn State), A. J. Levan (U. Warwick),\nN. R. Tanvir, and K. Wiersema (U. Leicester) report on behalf of a larger\ncollaboration:\n\nWe obtained spectroscopy of the optical afterglow (Immler et al., GCN 11159;\nGuidorzi et al., GCN 11160; Ivanov et al., GCN 11161; Klunko et al., GCN 11162)\nof GRB 100901A (Immler et al., GCN 11159) using GMOS on the Gemini-North 8-m\ntelescope starting on 2010 September 1.61 UT.  A set of four 400s observations\nwere obtained covering the wavelength range 3825-6675 Angstroms.  Numerous\nabsorption lines are present.  The highest redshift system is at z=1.408, with\nmany absorptions from Fe II, Al II, and Si II.  The presence of several Fe II*\nabsorptions establishes this as the redshift of the host galaxy of GRB 100901A.\n Two intervening systems at z=1.315 and 1.318 also have absorptions from Mg II\nand Fe II.\n\nWe thank A. Stephens and the Gemini staff for their help in obtaining these\nobservations.",
  "circularId": 11164,
  "createdOn": 1283360529000,
  "email": "rchornock@cfa.harvard.edu",
  "subject": "GRB 100901A: Gemini-N Redshift",
  "submitter": "Ryan Chornock at Harvard  <rchornock@cfa.harvard.edu>",
  "eventId": "GRB 100901A"
}