2008/12/31 by N. P. M. Kuin, W. Landsman, W. B. Landsman +30
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Brightness #Galaxy #Gamma-ray burst #Gamma-ray bursts and supernovae #Grism #Optical telescope #Optics #Physics #Redshift #Stellar, planetary, and galactic studies #Swift #Telescope #Ultraviolet #astro-ph
paper · pdf · doi:10.1111/j.1745-3933.2009.00632.x
4 pages, 4 figures, accepted by MNRAS letters
arxiv created 2009/01/28 · openalex publication_date 2009/02/26 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Abstract We present the earliest ultraviolet (UV) spectrum of a gamma-ray burst (GRB) as observed with the Swift Ultra-Violet/Optical Telescope (UVOT). The GRB 081203A spectrum was observed for 50 s with the UV-grism starting 251 s after the Swift-Burst-Alert-Telescope (BAT) trigger. During this time, the GRB was ≈13.4 mag (u filter) and was still rising to its peak optical brightness. In the UV-grism spectrum, we find a damped Lyα line, Lyβ and the Lyman continuum break at a redshift z= 2.05 ± 0.01. A model fit to the Lyman absorption implies a gas column density of log NH i= 22.0 ± 0.1 cm−2, which is typical of GRB host galaxies with damped Lyα absorbers. This observation of GRB 081203A demonstrates that for brighter GRBs (v≈ 14 mag) with moderate redshift (0.5 < z < 3.5) the UVOT is able to provide redshifts, and probe for damped Lyα absorbers within 4–6 min from the time of the Swift-BAT trigger.