{
  "bibcode": "2014GCN.16301....1C",
  "body": "R. Chornock (Harvard), D. B. Fox (Penn State), A. Cucchiara (Goddard), D. A. \nPerley (Caltech), and A. Levan (Warwick) report on behalf of a larger collaboration:\n\nWe obtained 2x900s of spectroscopy of the optical afterglow (Zheng et al., GCN \n16299; Perley et al., GCN 16300) of GRB140518A (Melandri et al., GCN 16298) \nusing GMOS on the 8-m Gemini-North telescope starting at 12:22 UT on May 18. Our \nspectra covered the wavelength range 5900-10150 Angstroms at a resolution of \nR~1200. A damped Lyman-alpha system is present near 6940 Angs, corresponding to \nz~4.71.  A fit to the absorber gives z=4.706 and the log of the HI column \ndensity (in cm^-2) is 21.65 +- 0.1. Strong narrow absorption lines of S II, Si \nII, Si II*, O I, O I*, Si IV, C II, C IV, Fe II, and Al II associated with this \nabsorption system have a common redshift of z=4.707.  The combination of the DLA \nand the excited fine structure lines allow us to identify this as the redshift \nof the GRB.\n\nWe thank the Gemini staff, in particular Rachel Mason and Joy Chavez, for their \nassistance with these observations.",
  "circularId": 16301,
  "createdOn": 1400421718000,
  "email": "rchornock@cfa.harvard.edu",
  "subject": "GRB 140518A: Gemini-N redshift",
  "submitter": "Ryan Chornock at Harvard  <rchornock@cfa.harvard.edu>",
  "eventId": "GRB 140518A"
}