THE FIRST SYSTEMATIC STUDY OF TYPE Ibc SUPERNOVA MULTI-BAND LIGHT CURVES

We present detailed optical photometry for 25 Type Ibc supernovae (SNe Ibc) within d approximate to 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 Delta t approximate to 10 days after V-band maximum is tightly distributed, <(V - R)(V10)> = 0.26 +/- 0.06 mag. Using this technique, we find that SNe Ibc typically suffer from significant host galaxy extinction, < E(B - V)> approximate to 0.4 mag. 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 +/- 0.9 mag and < M-R > = -18.3 +/- 0.6 mag 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, < M-R > = -19.0 +/- 1.1 mag, 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-SN 1998bw, XRF-SN 2006aj, and SN 2009bb) 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 Ni-56 masses of M-Ni approximate to 0.2 and 0.5 M-circle dot 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 approximate to 2 M-circle dot and E-K approximate to 10(51) erg for SNe Ibc, while for SNe Ic-BL we find higher values, M-ej approximate to 5 M-circle dot and E-K approximate to 10(52) erg. We discuss the implications for the progenitors of SNe Ibc and their relation to those of engine-driven explosions.