{
  "submitter": "Nat Butler at Az State U  <natbutler@asu.edu>",
  "editedBy": "Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>",
  "editedOn": 1731008902311,
  "subject": "GRB 131127A: RATIR Optical and NIR Observations, High-z Candidate",
  "createdOn": 1385628113000,
  "email": "natbutler@asu.edu",
  "version": 2,
  "bibcode": "2013GCN.15525....1B",
  "format": "text/plain",
  "circularId": 15525,
  "eventId": "GRB 131127A",
  "body": "Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William\nH. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB),\nJ. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara\n(ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico\nRamirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús\nGonzález (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and\nHarvey Moseley (GSFC) report:\n\nWe observed the field of GRB 131127A (Markwardt, et al., GCN 15516) with\nthe Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on\nthe 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional\non Sierra San Pedro Mártir from 2013/11 28.11 to 2013/11 28.26 UTC (16.42\nto 19.94 hours after the BAT trigger), obtaining a total of 2.49 hours\nexposure in the r and i bands and 1.04 hours exposure in the Z, Y, J, and H\nbands.\n\nWe do not detect any sources within the Enhanced Swift-XRT error circle\n(Evans et al., GCN 15520), in comparison with 2MASS, we obtain the\nfollowing upper limits (3-sigma):\n\n  r > 24.19\n  i > 23.53\n  Z > 22.78\n  Y > 22.16\n  J > 22.04\n  H > 21.48\n\nHowever, we do detect a red source just outside (3.3\" away from the center)\nof the XRT position, at a position RA, DEC = 332.731227 , 36.609171 (J2000,\n+/- 0.5\").  We measure:\n\n  r = 24.21 +/- 0.35\n  i = 22.48 +/- 0.11\n  Z = 21.85 +/- 0.16\n  Y = 21.22 +/- 0.15\n  J = 21.03 +/- 0.14\n  H = 20.88 +/- 0.20\n\nThe faint flux in r band relative to the redder bands could be due to IGM\nattenuation at high redshift, z ~ 5.  We cannot confirm fading of this\nsource.  Further observations of this source are encouraged.\n\nThe magnitudes above are in the AB system and are not corrected for\nGalactic extinction, E[B-V]~0.1, in the direction of the GRB.\n\nWe thank the staff of the Observatorio Astronómico Nacional in San Pedro\nMártir."
}