2010/12/07 by Z. Cano, D. Bersier, C. Guidorzi +75 · 4 citations
Engineering · Physics and Astronomy · #Afterglow #Astrophysics and Cosmic Phenomena #Brightness #CCD and CMOS Imaging Sensors #Context (archaeology) #Extinction (optical mineralogy) #Gamma-ray burst #Gamma-ray bursts and supernovae #Light curve #Redshift #Supernova #astro-ph.CO
paper · pdf · doi:10.1111/j.1365-2966.2010.18164.x
published as MNRAS, 413, 669 (2011) · Accepted for publication in MNRAS on Dec 07, 2010. 18 pages, 12 figures, 9 tables
arxiv created 2010/12/07 · openalex publication_date 2011/02/10 · arxiv updated 2015/03/17 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
We present ground-based and Hubble Space Telescope optical observations of the optical transients (OTs) of long-duration Gamma Ray Bursts (GRBs) 060729 and 090618, both at a redshift of z=0.54. For GRB 060729, bumps are seen in the optical light curves (LCs), and the late-time broad-band spectral energy distributions (SEDs) of the OT resemble those of local Type Ic supernovae (SNe). For GRB 090618, the dense sampling of our optical observations has allowed us to detect well-defined bumps in the optical LCs, as well as a change in colour, that are indicative of light coming from a core-collapse SN. The accompanying SNe for both events are individually compared with SN1998bw, a known GRB supernova, and SN1994I, a typical Type Ic supernova without a known GRB counterpart, and in both cases the brightness and temporal evolution more closely resemble SN1998bw. We also exploit our extensive optical and radio data for GRB 090618, as well as the publicly available Swift-XRT data, and discuss the properties of the afterglow at early times. In the context of a simple jet-like model, the afterglow of GRB 090618 is best explained by the presence of a jet-break at t − to > 0.5 d.\nWe then compare the rest-frame, peak V-band absolute magnitudes of all of the GRB and X-Ray Flash (XRF)-associated SNe with a large sample of local Type Ibc SNe, concluding that, when host extinction is considered, the peak magnitudes of the GRB/XRF-SNe cannot be distinguished from the peak magnitudes of non-GRB/XRF SNe.