The Double-peaked Radio Light Curve of Supernova PTF11qcj
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 γ-ray burst (GRB) associated SN 1998bw. The latest radio observations, carried out with the Karl G. Jansky Very Large Array, extend up to ∼5 yr 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. Optical spectra of PTF11qcj taken during both peaks of the radio light curve do not show the broad Hα features typically expected from H-rich circumstellar interaction. Modeling of the second radio peak within the CSM-interaction scenario requires a flatter density profile and an enhanced progenitor mass-loss rate compared to those required to model the first peak. Our radio data alone cannot rule out the alternative scenario of an off-axis GRB powering the second radio peak, but the derived GRB parameters are somewhat unusual compared to typical values found for cosmological long GRBs. On the other hand, 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 conclude that VLBI measurements of the PTF11qcj radio ejecta are needed to unambiguously confirm or rule out the off-axis GRB jet scenario.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2019
- DOI:
- arXiv:
- arXiv:1802.09683
- Bibcode:
- 2019ApJ...872..201P
- Keywords:
-
- supernovae: general;
- supernovae: individual: PTF11qcj;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 13 pages, 6 figures