{
  "bibcode": "2016GCN.19710....1C",
  "body": "A. J. Castro-Tirado (IAA-CSIC), A. F. Valeev (SAO-RAS), S. Jeong (SKKU), \nR. S��nchez-Ram��rez (IAA-CSIC), V. V. Sokolov (SAO-RAS), P. Ferrero \n(IAA-CSIC), J. C. Tello (IAA-CSIC), Y. Hu (IAA-CSIC), B.-B. Zhang \n(IAA-CSIC), A. Pozanenko (IKI-RAS), S. R. Oates (U. of Warwick), S. \nGeier (GTC) and G. Lombardi (GTC), on behalf of a larger collaboration, \nreport:\n\nFollowing the detection of GRB 160623A by Fermi (Vianello et al. GCNC \n19553) and Konus-Wind (Frederiks et al. GCNC 19554), we observed the \noptical afterglow of GRB 160623A (Pozanenko et al. GCNC 19561) with the \n10.4m Gran Telescopio Canarias (GTC), gathering spectra at different \nepochs: June 25 (1.9 days post-burst) and July 3/4, with both the R1000B \nand R2500I grisms covering the range 3800-10000 A. At the position of \nthe afterglow, the reddest spectrum (2 x 1200s with R2500I) showed \nH-alpha and [SII] in emission, from which we determine a redshift z = \n0.367, confirming the value proposed by Malesani et al. (GCNC 19708). \nThe bluest range spectrum (1200s) also revealed a marginal detection of \nH-beta (taking into account the high foreground Galactic extinction in \nthe line of sight). The faint continuum on the first epoch spectrum \nextended down to 3800 A with no absorption lines being present. \nTherefore we propose this is the redshift of the GRB 160623A host \ngalaxy.\n\nWe acknowledge excellent support from the GTC staff.",
  "circularId": 19710,
  "createdOn": 1468521882000,
  "email": "ajct@iaa.es",
  "subject": "GRB 160623A: afterglow spectroscopy by GTC and independent redshift determination",
  "submitter": "Alberto Castro-Tirado at Inst.de Astro. de Andalucia  <ajct@iaa.es>",
  "eventId": "GRB 160623A"
}