{
  "bibcode": "2009GCN..9322....1R",
  "body": "D. A. Riechers (Caltech), F. Walter (MPIA Heidelberg), F. Bertoldi\n(AIfA Bonn), C. L. Carilli (NRAO), P. Cox (IRAM), C. Kramer (IRAM),\nD. Riquelme (IRAM) report:\n\n\"We used the Max-Planck-Millimeter Bolometer (MAMBO-2) array at the\nIRAM 30-m telescope to observe the field of view toward the host\ngalaxy of GRB 090423 (GCN 9198) at redshift z=8.2 (GCN 9219), RA\n09:55:33.19, Dec +18:08:57.7 (J2000) at 250 GHz. Observations were\ncarried out for 4.5 hr on 2009 April 25, centered at UT 18.5.  We\nobtained a non-detection of\n\n    S_nu(250 GHz,1.20 mm) = 0.23 +/- 0.32 mJy\n\n(1 sigma error), i.e. a 3 sigma upper flux density limit of 0.96 mJy\non the GRB afterglow and the dust continuum in the host galaxy at 1.2\nmm (rest-frame 130 um). Together with the 3 mm observations carried\nout at the Plateau de Bure Interferometer (GCN 9273), this indicates a\nflat spectral slope at millimeter wavelengths. The 117-element MAMBO-2\nbolometer detectors cover 210-290 GHz (half power). The bolometers\nhave a FWHM beam size of 10.7 arcsec, at a pixel spacing of 20\narcsec. Observations were carried out in ON-OFF observing mode under\ngood weather conditions, with low sky noise and opactities of\ntau=0.1-0.26 (derived from skydips). Calibrations were performed on\nCW-LEO.\n\nWe acknowledge the excellent support of the staff at IRAM. IRAM is\nsupported by INSU/CNRS (France), MPG (Germany), and IGN (Spain). This\nmessage may be cited.\"",
  "circularId": 9322,
  "createdOn": 1241461280000,
  "email": "dr@caltech.edu",
  "subject": "GRB 090423: 250 GHz upper limit for a z=8.2 GRB with MAMBO-2 at the IRAM 30m",
  "submitter": "Dominik A. Riechers at Caltech  <dr@caltech.edu>",
  "eventId": "GRB 090423"
}