TITLE: GCN CIRCULAR NUMBER: 14088 SUBJECT: GRB 121123A: NIKA (New IRAM KID Arrays) millimetre observations at the 30-m Pico Veleta telescope DATE: 12/12/16 09:29:40 GMT FROM: Alessandro Monfardini at CNRS,Grenoble A. Monfardini (I. Néel, Grenoble), F.-X. Désert (IPAG, Grenoble), N. Ponthieu (IPAG, Grenoble), R. Adams (LPSC, Grenoble), M. Calvo (I. Néel, Grenoble), J. Macias-Perez (LPSC, Grenoble), A. Catalano (LPSC, Grenoble), S. Leclercq (IRAM, Grenoble), P. Mauskopf (Arizona State U. & Cardiff U.), A. Benoit (I. Néel, Grenoble), on behalf of the NIKA collaboration, report: "During a technical run, we observed the position of GRB 121123A (E. A. Helder et al., GCN 13982) with the NIKA instrument being commissioned at the IRAM 30-m at Pico Veleta. Observations were accomplished between 15h and 16h UT on 24th November 2012 (mean time 29.5 hours after the burst), under poor observing conditions (tau225GHz ~ 0.35) and at relatively low elevation (35 deg). In roughly 40 minutes effective time on source, we do not detect the afterglow at the position given by D. Xu et al., GCN 13986. The following 3-sigma upper limits were derived: U.L. 3 mJy at 150 GHz (99.7% C.L.) U.L. 40 mJy at 240 GHz (99.7% C.L.), strongly limited by unstable weather conditions NIKA is a multi-hundred-pixels dual-band continuum instrument operating simultaneously at central frequencies of 150 GHz (bandwidth 40 GHz) and 240 GHz (bandwidth 60 GHz). It is the first instrument based on the intrinsically multiplexable KID (Kinetic Inductance Detectors) technology installed permanently at a telescope. For more information about the instrument and the future project NIKA-2, see A. Monfardini et al., ApJS 194, Issue 2, id. 24 (2011). We thank the IRAM Granada and Grenoble staff for their outstanding support before, during and after the NIKA run."