2008/05/31 by P. Kumar, A. Panaitescu · 2 citations
Engineering · Physics and Astronomy · #Afterglow #Astronomy and Astrophysical Research #CCD and CMOS Imaging Sensors #Ejecta #Gamma-ray burst #Gamma-ray bursts and supernovae #Jet (fluid) #Lorentz factor #Outflow #Photon #Synchrotron #Synchrotron radiation #astro-ph
paper · pdf · doi:10.1111/j.1745-3933.2008.00546.x
published as Mon.Not.Roy.Astron.Soc. 391:L19-23,2008 · 5 pages, to appear in MNRAS Letters, potential difficulties of the SSC model discussed in S2.2
arxiv created 2008/08/12 · openalex publication_date 2008/09/30 · arxiv updated 2010/05/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Abstract The optical and gamma-ray observations of GRB 080319B allow us to provide a broad-brush picture for this remarkable burst. The data indicate that the prompt optical and gamma-ray photons were possibly produced at the same location but by different radiation processes: synchrotron and synchrotron self-Compton, respectively (but we note that this interpretation of the gamma-ray data faces some difficulties). We find that the burst prompt optical emission was produced at a distance of 1016.3 cm by an ultrarelativistic source moving at Lorentz factor of ∼500. A straightforward inference is that about 10 times more energy must have been radiated at tens of GeV than that released at 1 MeV. Assuming that the GRB outflow was baryonic and the gamma-ray source was shock-heated plasma, the collimation-corrected kinetic energy of the jet powering GRB 080319B was larger than 1052.3 erg. The decay of the early afterglow optical emission (up to 1 ks) is too fast to be attributed to the reverse-shock crossing the GRB ejecta but is consistent with the expectations for the ‘large-angle’ emission released during the burst. The pure power-law decay of the optical afterglow flux from 1 ks to 10 d is most naturally identified with the (synchrotron) emission from the shock propagating into a wind-like medium. However, the X-ray afterglow requires a departure from the standard blast-wave model.