Properties of Type II Plateau Supernova SNLS-04D2dc: Multicolor Light Curves of Shock Breakout and Plateau
Abstract
Shock breakout is the brightest radiative phenomenon in a Type II supernova (SN). Although it was predicted to be bright, the direct observation is difficult due to the short duration and X-ray/ultraviolet-peaked spectra. First entire observations of the shock breakouts of Type II Plateau SNe (SNe IIP) were reported in 2008 by ultraviolet and optical observations by the GALEX satellite and supernova legacy survey (SNLS), named SNLS-04D2dc and SNLS-06D1jd. We present multicolor light curves of a SN IIP, including the shock breakout and plateau, calculated with a multigroup radiation hydrodynamical code STELLA and an evolutionary progenitor model. The synthetic multicolor light curves reproduce well the observations of SNLS-04D2dc. This is the first study to reproduce the ultraviolet light curve of the shock breakout and the optical light curve of the plateau consistently. We conclude that SNLS-04D2dc is the explosion with a canonical explosion energy 1.2×1051 ergs and that its progenitor is a star with a zero-age main-sequence mass 20M and a presupernova radius 800R. The model demonstrates that the peak apparent B-band magnitude of the shock breakout would be m B26.4 mag if a SN being identical to SNLS-04D2dc occurs at a redshift z=1, which can be reached by 8m-class telescopes. The result evidences that the shock breakout has a great potential to detect SNe IIP at z1.