The double-peaked radio light curve of supernova PTF11qcj- Evidence for an off-axis jet?
Abstract
We present continued radio and X-ray follow--up observations of PTF11qcj, a highly energetic broad-lined Type Ic supernova (SN), with a radio peak luminosity comparable to that of the gamma-ray burst (GRB) associated SN 1998bw. The latest radio observations, carried out with the Karl G. Jansky Very Large Array (VLA), extend up to ~5 years after the PTF11qcj optical discovery. The radio light curve shows a double--peak profile, possibly associated with density variations in the circumstellar medium (CSM), or with the presence of an off-axis GRB jet. Radio modeling of the second peak within the CSM interaction scenario requires a flatter density profile and an enhanced progenitor mass--loss rate compared to the first peak. While radio data alone cannot rule out an off--axis GRB powering the second radio peak, the derived GRB parameters are somewhat unusual compared to typical values found for cosmological long GRBs. Our Chandra X-ray observations carried out during the second radio peak are compatible with the off-axis GRB hypothesis, within the large measurement errors. We further discuss the possibility of unambiguously confirming or ruling out the off-axis GRB jet scenario with VLBI direct size measurements and the possibility of utilizing polarization observations to probe the post-shock magnetic field structure.
- Publication:
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American Astronomical Society Meeting Abstracts #233
- Pub Date:
- January 2019
- Bibcode:
- 2019AAS...23325809P