{
  "bibcode": "2001GCN..1108....1D",
  "body": "GRB010921: Spectroscopy of the Host Galaxy\n\nS.G. Djorgovski, A. Mahabal, P.A. Price, J.S. Bloom, D.E. Reichart, E. Berger, \nD.W. Fox, S.R. Kulkarni, D.A. Frail, R. Sari, T. Galama, F. Harrison, and \nS. Yost report on behalf of the Caltech-NRAO-CARA GRB collaboration: \n\n\"We obtained a spectrum of the host galaxy of the proposed afterglow of \nGRB010921 (Price et al., GCN 1107) using the Double Spectrograph at the\nPalomar 200-inch telescope, on 17 October 2001 UT.  Preliminary reductions\nof the spectrum indicate a redshift of z = 0.450 +- 0.005, on the basis of \n4 emission lines, [O II] 3727, H-beta, [O III] 5007, and H-alpha.  The \nspectrum is typical for an actively star-forming galaxy, with no sign of \nan active nucleus.  Further analysis is in progress.\n\nAssuming an H_0 = 65 km/s/Mpc, Omega_m = 0.3, Omega_lambda = 0.7 cosmology,\nwe derive the luminosity distance of 8.30e+27 cm.  Using the fluence of \n1.0e-6 erg/cm2 (Ricker et al. GCN #1096), the total energy release in the \nrestframe range 12-123 keV (redshifted bandpass of the HETE band at 8-85 keV) \nis 6.0e+50 erg.  Though no spectral information was reported, we estimate that \nthe isotropic equivalent energy release in the 20-2000 keV range (see Bloom\net al. 2001, AJ, 121, 2879) was E_iso(gamma) = (2.65 +- 1.45)e+51 erg.\n\nTo conform with the constant energy of E_gamma = 5e+50 erg (Frail et al.\n2001, ApJ Letters, accepted; astro-ph/0102282), the time of the jet break \nwould be t_jet ~ 130 days after the GRB.  However, a possible supernova \nassociated with this event may be detectable now.\"\n\nThis note can be cited.",
  "circularId": 1108,
  "createdOn": 1003510257000,
  "email": "george@astro.caltech.edu",
  "eventId": "GRB 010921",
  "subject": "GRB010921: Spectroscopy of the Host Galaxy",
  "submitter": "George Djorgovski at Caltech/Palomar  <george@astro.caltech.edu>"
}