Type II-Plateau supernova radiation: dependencies on progenitor and
  explosion properties
  We explore the properties of Type II-Plateau (II-P) supernovae (SNe) together
with their red-supergiant (RSG) star progenitors. Using MESA STAR, we modulate
the parameters (e.g., mixing length, overshoot, rotation, metallicity) that
control the evolution of a 15Msun main-sequence star to produce a variety of
physical pre-SN models and SN II-P ejecta. We extend previous modeling of SN
II-P radiation to include photospheric and nebular phases, as well as
multi-band light curves and spectra. Our treatment does not assume local
thermodynamic equilibrium, is time dependent, treats explicitly the effects of
line blanketing, and incorporates non-thermal processes. We find that the color
properties of SNe II-P require large model atoms for FeI and FeII, much larger
than adopted in Dessart & Hillier (2011). The color properties also imply RSG
progenitors of limited extent (~500Rsun) --- larger progenitor stars produce a
SN II-P radiation that remains too blue for too long. This finding calls for a
reduction of RSG radii, perhaps through a strengthening of convective energy
transport in RSG envelopes. Increased overshoot and rotation reduce the ratio
of ejecta to helium-core mass, similarly to an increase in main-sequence mass,
and thus complicate the inference ofprogenitor masses. In contrast to the great
sensitivity on progenitor radius, SN II-P color evolution appears insensitive
to variations in explosion energy. Finally, we document the numerous SN II-P
signatures that vary with progenitor metallicity, revealing their potential for
metallicity determinations in the nearby and distant Universe.
