{
  "bibcode": "2011GCN.11522....1X",
  "body": "D. Xu, A. Gal-Yam (WIS), J. P. U. Fynbo (DARK/NBI), report on behalf\nof a large collaboration:\n\nSpectroscopy of the host galaxy of GRB 101225A (Racusin et al., GCN\n11493; Xu et al. GCN 11519) was carried out at the 10m Keck-I\ntelescope equipped with the Low Resolution Imaging Spectrometer (LRIS)\naround 10 UT, 6th Jan. 2011, with a good seeing ~0.7\". A 900s spectrum\nwas obtained and it consists of a red and a blue channels, covering\n~3200-5500 A and ~5000-8200 A, respectively. The spectrum has a low\nsignal-to-noise ration and the trace is best detected in the red\nchannel. Three weak emission lines are found at a common redshift of\nz=0.40, considered as Hbeta (4861 AA), and the O III (4960 AA, 5007\nAA).\n\nIsotropic energy: >~ 7.8+/-1.6 x10^50 erg, using the BAT fluence\n(Palmer et al., GCN 11500)\n\nThe absence of evidence for an emerging SN at the above redshift\nsuggests that GRB 101225A is a SN-less or SN-weak long GRB event.\n\nFurther deep spectroscopic observations are encouraged.",
  "circularId": 11522,
  "createdOn": 1294344820000,
  "email": "dong@astro.ku.dk",
  "subject": "GRB 101225A: Keck redshift",
  "submitter": "Dong Xu at Weizmann Inst  <dong@astro.ku.dk>",
  "eventId": "GRB 101225A"
}