SIMBAD references

Among a number of gamma-ray bursts whose host galaxies are known, GRB 971214 stands out for its high redshift (z≥3) and the Lyα emission line having a P Cygni-type profile, which is interpreted to be a direct consequence of the expanding supershell. From a profile-fitting analysis, we estimate the expansion velocity of the supershell (v_exp=1500 km.s^–1) and the neutral column density (N_HI_=10²⁰ cm^–2). The redshift z=3.418 of the host galaxy proposed by Kulkarni et al. in 1998 has been revised to be z=3.425 from our profile analysis. The observed Lyα profile is fitted well by a Gaussian curve, which yields the Lyα luminosity L_Lyα=(1.8±0.8)x10⁴² ergs.s^–1. Assuming that the photon source is a giant H II region, we deduce the electron number density in the H II region n_e=(40±10)(L/L_Lyα)^0.5(R/100pc)^–1.5 cm^–3, which corresponds to the illumination by about 10⁴ O5 stars. We estimate the star formation rate to be R_SF=7±3 M_☉.yr^–1 with the internal and the Galactic extinction corrected. The theory on the evolution of supernova remnants is used to propose that the supershell is at the adiabatic phase, with its radius R=18E^1/2₅₃ pc, its age t=4.7x10³E^1/2₅₃ yr, and the density of the ambient medium n₁=5.4E^–1/2₅₃ cm^–3, where E₅₃=E/10⁵³ ergs; we estimate the kinetic energy of the supershell to be E_k=7.3x10⁵²E₅₃ ergs. These values are consistent with the hypothesis that the supershell is the remnant of a gamma-ray burst. We note similarities between supershells found in nearby galaxies and remote primeval galaxies and propose that the gamma-ray burst may have occurred in a giant H II region whose environment is similar to that in star-forming galaxies.