2001/07/18 by A. Yoshida, M. Namiki, D. Yonetoku +9 · 6 citations
Chemistry · Physics and Astronomy · #Absorption (acoustics) #Absorption edge #Afterglow #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Chemistry #Galaxy #Gamma-ray burst #Gamma-ray bursts and supernovae #Ion #Ionization #Optics #Physics #Radiative transfer #Recombination #Redshift #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/323143
To appear in the Astrophysical Journal Letters, 13 pages including 2 figures.(Companion paper: Yonetoku et al. (2001))
arxiv created 2001/07/18 · openalex publication_date 2001/08/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
A gamma-ray burst (GRB) of 1997 August 28 was localized by the All-Sky Monitor on the Rossi X-Ray Timing Explorer satellite, and its coordinates were promptly disseminated. An ASCA follow-up started 1.17 days after the burst as a Target-of-Opportunity Observation and detected an X-ray afterglow. The spectral data displayed a hump around ~5 keV and an absorption column of 7.1 × 10 21 cm -2 . Taking into account the redshift z = 0.9578 found for the likely host galaxy of the associated radio flare, this hump structure is likely a recombination edge of iron in the vicinity of the source. The radiative recombination edge and continuum model can interpret the spectrum from highly ionized plasma in a nonequilibrium ionization state. The absorption could also be due to the medium presumably residing in the vicinity of the GRB.