- Corsi, A;
- Ofek, EO;
- Gal-Yam, A;
- Frail, DA;
- Kulkarni, SR;
- Fox, DB;
- Kasliwal, MM;
- Sullivan, M;
- Horesh, A;
- Carpenter, J;
- Maguire, K;
- Arcavi, I;
- Cenko, SB;
- Cao, Y;
- Mooley, K;
- Pan, Y-C;
- Sesar, B;
- Sternberg, A;
- Xu, D;
- Bersier, D;
- James, P;
- Bloom, JS;
- Nugent, PE
We present the discovery, classification, and extensive panchromatic (from radio to X-ray) follow-up observations of PTF11qcj, a supernova (SN) discovered by the Palomar Transient Factory (PTF). Our observations with the Karl G. Jansky Very Large Array show that this event is radio-loud: PTF11qcj reached a radio peak luminosity comparable to that of the famous gamma-ray-burst-associated SN 1998bw (L 5 GHz 1029 erg s-1 Hz-1). PTF11qcj is also detected in X-rays with the Chandra Observatory, and in the infrared band with Spitzer. Our multi-wavelength analysis probes the SN interaction with circumstellar material. The radio observations suggest a progenitor mass-loss rate of 10-4 M yr-1 × (vw /1000 km s-1), and a velocity of 0.3-0.5 c for the fastest moving ejecta (at 10 days after explosion). However, these estimates are derived assuming the simplest model of SN ejecta interacting with a smooth circumstellar wind, and do not account for possible inhomogeneities in the medium and asphericity of the explosion. The radio data show deviations from such a simple model, as well as a late-time re-brightening. The X-ray flux from PTF11qcj is compatible with the high-frequency extrapolation of the radio synchrotron emission (within the large uncertainties). A light echo from pre-existing dust is in agreement with our infrared data. Our pre-explosion data from the PTF suggest that a precursor eruption of absolute magnitude Mr -13 mag may have occurred 2.5 yr prior to the SN explosion. Overall, PTF11qcj fits the expectations from the explosion of a Wolf-Rayet star. Precursor eruptions may be a feature characterizing the final pre-explosion evolution of such stars. © 2014. The American Astronomical Society. All rights reserved..