{
  "bibcode": "2000GCN...731....1H",
  "body": "Stephen Holland, Bjarne Thomsen (University of Aarhus),\nMichael Andersen (University of Oulu),\nGunnlaugur Bjornsson (University of Iceland),\nJohan Fynbo, Jens Hjorth (University of Copenhagen),\nAndreas Jaunsen (University of Oslo),\nPriya Natarajan (University of Cambridge, & Yale), and\nNial Tanvir (University of Hertfordshire)\n\n     We have obtained 7856 seconds of STIS images with the 50CCD (clear) \naperture and 8000 seconds with the F28X50LP (long pass) aperture of the sky \nwhere the radio afterglow associated with GRB 990506 was detected.  This \ndata was taken as part of the Survey of the Host Galaxies of Gamma-Ray Bursts \n(Holland et al. GCN 698) approximately 413 days after the burst.  Combined \n(drizzled) FITS and GIF images are now available at the interim web site\n\"http://www.astro.uio.no/~ajaunsen/grb-hosts/\".  The images will be made \navailable at the official survey web site\n\"http://www.ifa.au.dk/~hst/grb_hosts/data/index.html\" next week.\n\n     At the location of the radio afterglow (Taylor et al. astro-ph/0005379) \nthere is a very compact galaxy (FWHM ~ 0.14\") which we identify as the probable \nhost galaxy for GRB 990506.  This galaxy does not appear to be associated or \ninteracting with a larger galaxy (2\" in extent) located 2 arcsec to the north \neast (the \"northeast knot\" of Taylor et al.).  A preliminary photometric \ncalibration of the STIS data yields R = 25.0 +- 0.3 for the host galaxy. It \nthus appears to be marginally fainter than the value R = 24.4 +- 0.3 measured \non 11 June 1999 (36 days after the burst) in LRIS/Keck II images. This could \nindicate a contribution from an optical transient (afterglow or supernova) at \nthe time of the Keck observations.  A more accurate transformation from 50CCD \nand F28X50LP to Cousins R is however necessary to rule out calibration errors.\n\n     We finally note that the radio source R2, identified by Taylor et al. to\nbe a QSO at z = 0.273, is resolved in the STIS images.  The morphology is that\nof a spiral galaxy (2 arcsec in diameter) with a bright nucleus and several\nknots in the spiral arms. Thus, R2 is a radio loud QSO with a spiral host \ngalaxy.",
  "circularId": 731,
  "createdOn": 962110948000,
  "email": "jens@astro.ku.dk",
  "subject": "GRB 990506, HST/STIS Observations of the Host Galaxy",
  "submitter": "Jens Hjorth at U.Copenhagen  <jens@astro.ku.dk>",
  "eventId": "GRB 990506"
}