The first systematic study of type Ibc supernova multi-band light curves

Abstract

We present detailed optical photometry for 25 Type Ibc supernovae (SNe Ibc) within d ≈ 150 Mpc obtained with the robotic Palomar 60 inch telescope in 2004-2007. This study represents the first uniform, systematic, and statistical sample of multi-band SNe Ibc light curves available to date. We correct the light curves for host galaxy extinction using a new technique based on the photometric color evolution, namely, we show that the (V - R) color of extinction-corrected SNe Ibc at Δt ≈ 10 days after V-band maximum is tightly distributed, 〈(V - R)V10〉 = 0.26 ± 0.06mag. Using this technique, we find that SNe Ibc typically suffer from significant host galaxy extinction, 〈E(B - V)〉 ≈ 0.4mag. A comparison of the extinction-corrected light curves for helium-rich (Type Ib) and helium-poor (Type Ic) SNe reveals that they are statistically indistinguishable, both in luminosity and decline rate. We report peak absolute magnitudes of 〈M R 〉 = -17.9 ± 0.9mag and 〈MR 〉 = -18.3 ± 0.6mag for SNe Ib and Ic, respectively. Focusing on the broad-lined (BL) SNe Ic, we find that they are more luminous than the normal SNe Ibc sample, 〈MR 〉 = -19.0 ± 1.1mag, with a probability of only 1.6% that they are drawn from the same population of explosions. By comparing the peak absolute magnitudes of SNe Ic-BL with those inferred for local engine-driven explosions (GRB-SN1998bw, XRF-SN2006aj, and SN2009bb) we find a 25% probability that relativistic SNe are drawn from the overall SNe Ic-BL population. Finally, we fit analytic models to the light curves to derive typical 56Ni masses of M Ni ± 0.2 and 0.5 M ⊙ for SNe Ibc and SNe Ic-BL, respectively. With reasonable assumptions for the photospheric velocities, we further extract kinetic energy and ejecta mass values of M ej ≈ 2 M ⊙ and EK ≈ 1051erg for SNe Ibc, while for SNe Ic-BL we find higher values, M ej ≈ 5 M ⊙ and EK ≈ 1052erg. We discuss the implications for the progenitors of SNe Ibc and their relation to those of engine-driven explosions. © 2011. The American Astronomical Society. All rights reserved.