{
  "bibcode": "2000GCN...702....1B",
  "body": "The Hosts of GRB 980703 and GRB 971214\n\nJ. S. Bloom and S. R. Kulkarni report on behalf of the larger\nCaltech-NRAO-CARA GRB Collaboration:\n\n\"The Hubble Space Telescope (HST) has recently observed the hosts of GRB\n971214 and GRB 980703 with STIS as part of the Survey of the Host Galaxies\nof Gamma-Ray Bursts (see S. Holland, B. Thomsen, H. Hjorth et al. GCN\n#698).  Here we present our data reduction of this public data and relate\nthe new STIS images to our previously obtained ground-based data and\nspace-based data.\n\nGRB 980703:\nThis remains one of the brightest GRB host galaxies at R~22.8 and the\ninferred GRB energy release is at the high end of the GRBs energy\ndistribution. The optical astrometry tie from Bloom et al. (1998,\nApJL 508, 21) revealed the GRB to be nearly coincident with its host\ngalaxy.\n\nThe GRB host was observed for a total of 5264 s with the STIS long-pass\nfilter (central wavelength ~ 7230 Ang and FWHM 2720 Ang) beginning 12.42\nJune 2000 UT. The galaxy is compact (though resolved) and has a low\nellipticity (~12%).  The effective seeing of the drizzled image is 85\nmilliarcsec (FWHM) as measured from a bright star in the image and the\nhost has a FWHM diameter of 250 milliarcsec.  This is consistent with our\nreport in Bloom et al. of an unresolved source in 0.5 arcsec seeing on\nJuly 18 (when the host was thought to dominate the total light of the\nsource).  At a redshift of z=0.966 (Djorgovski et al. ApJL 508, 17, 1998),\nthis implies a half-light radius of ~1.1 kpc (assuming H_0 = 65 km/s/Mpc,\nOmega_0 = 0.3, Omega_lam = 0.7).\n\nFor photometric zero-pointing of the HST image, we compared two compact\nobjects in common to our deep Keck images from 18 July 1998 in V, R, I.  \nWe find the host galaxy has R = 22.8 +/- 0.3 and I = 22.6 +/- 0.3.  The\nerror is dominated by the uncertainty in the color correction. These\nmagnitudes are both within 1-sigma of those predicted for the host galaxy\nin Bloom et al. from the light curve data.  We conclude therefore there is\nno evidence for the presence of a second light source (e.g. a supernova\ncomponent) in the early time light curve.\n\nGRB 971214:\nAt z=3.418, this burst and its host remains the furthest of GRBs with\nspectroscopically confirmed redshifts and also had an implied energy\nrelease at the high end of the GRB energy distribution (Kulkarni et al.\n1998, Nature, 393, 35). Using STIS imaging from 13 April 1998 we\npreviously reported (Odewahn et al. 1998 ApJL, 509, 5) the host as compact\ncore with an irregular envelope (half-light radius of 1.3 kpc).\nMorphologically and in all other observed physical properties the host is\nrather typical Lyman break galaxy at comparable redshifts.  Further, we\nfound a small but significant offset of the GRB from the nucleus of the\ngalaxy.\n\nThe GRB host was observed for 8599s using STIS clear mode beginning 12.21\nJun 2000 UT.  The final image has achieved approximately the same depth as\nour previous STIS clear imaging.  A visual comparison of the two epochs\nreveals no obvious new or fading component.  Our conclusions about the\nnature of the host and its relation to the GRB remain unchanged from\nOdewahn et al.\"\n\nOur final reduced images can be obtained in .fits format at\n   http://astro.caltech.edu/~jsb/GRB/Host/\n\nThis message may be cited.",
  "circularId": 702,
  "createdOn": 961033329000,
  "email": "jsb@astro.caltech.edu",
  "subject": "The Hosts of GRB 980703 and GRB 971214",
  "submitter": "Josh Bloom at CIT  <jsb@astro.caltech.edu>",
  "eventId": "GRB 980703"
}