The Radio Luminosity-Risetime Function of Core-Collapse Supernovae

Abstract

We assemble a large set of 2-10 GHz radio flux density measurements and upper limits of 294 different supernovae (SNe), from the literature and our own and archival data. Only 31% of the SNe were detected. We characterize the SN lightcurves near the peak using a two-parameter model, with tpk being the time to rise to a peak and Lpk the spectral luminosity at that peak. Over all SNe in our sample at D<100 Mpc, we find that tpk=101.7±0.9 d, and that Lpk=1025.5±1.6 erg s−1 Hz−1, and therefore that generally, 50% of SNe will have Lpk<1025.5 erg s−1 Hz−1. These Lpk values are ~30 times lower than those for only detected SNe. Types I b/c and II (excluding IIn's) have similar mean values of Lpk but the former have a wider range, whereas Type IIn SNe have ~10 times higher values with Lpk=1026.5±1.1 erg s−1 Hz−1. As for tpk, Type I b/c have tpk of only 101.1±0.5 d while Type II have tpk=101.6±1.0 and Type IIn the longest timescales with tpk=103.1±0.7 d. We also estimate the distribution of progenitor mass-loss rates, M˙, and find the mean and standard deviation of log10(M˙/Msol) yr−1 are −5.4±1.2 (assuming vwind=1000 km s−1) for Type I~b/c SNe, and −6.9±1.4 (assuming vwind=10 km s−1 for Type II SNe excluding Type IIn.