2000/07/31 by A. Smette, A. S. Fruchter, T. R. Gull +35 · 10 citations
Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysics #Extinction (optical mineralogy) #Galaxy #Gamma-ray burst #Gamma-ray bursts and supernovae #Hubble space telescope #Optics #Physics #Redshift #Space Telescope Imaging Spectrograph #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/321585
published in The Astrophysical Journal 556(1), 70-76 (IOP Publishing) · Replaced by final version. 10 p., 2 fig. Scheduled to appear in ApJ 555 n2 Jul 10, 2001. Minor changes, both redshift and mean near UV flux are revised with slightly larger values, due to a wrong offset sign in the wavelength calibration
arxiv created 2001/03/16 · openalex publication_date 2001/07/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We present Space Telescope Imaging Spectrograph observations of the optical transient (OT) counterpart of the γ-ray burster GRB 000301C obtained 5 days after the burst, on 2000 March 6. CCD clear-aperture imaging reveals a R ≃ 21.50 ± 0.15 source with no apparent host galaxy. An 8000 s, 1150 Å < λ < 3300 Å near-ultraviolet MAMA prism spectrum shows a flat or slightly rising continuum (in f λ ) between 2800 and 3300 Å, with a mean flux of × 10 -18 ergs s -1 cm -2 Å -1 , and a sharp break centered at 2797 ± 25 Å. We interpret this as the H I Lyman break at z = 2.067 ± 0.025, indicating the presence of a cloud with an H I column density log N > 18 on the line of sight to the OT. This measured redshift is conservatively a lower limit to the GRB redshift. However, as all other GRBs that have deep Hubble Space Telescope images appear to lie on the stellar field of a host galaxy, and as the large H I column density measured here and in later ground-based observations is unlikely on a random line of sight, we believe we are probably seeing absorption from H I in the host galaxy. In any case, this represents the largest direct redshift determination of a γ-ray burster to date. Our data are compatible with an OT spectrum represented by a power law with an intrinsic index α = 1.2 ( f ν ∝ ν -α ) and no extinction in the host galaxy, or with α = 0.5 and extinction by SMC-like dust in the OT rest frame with A V = 0.15. The large N and the lack of a detected host are similar to the situation for damped Lyα absorbers at z > 2.