Shock Breakout in Dense Circumstellar Material with Application to PS1-13arp

Abstract Shock breakout (SBO), the first expected electromagnetic signature of a supernova (SN), can be an important probe progenitors these explosions. Unfortunately, SBO is difficult to capture with current surveys due its brief timescale (≲1 hr). However, may lengthened when dense circumstellar material (CSM) present. Indeed, recent photometric modeling studies SNe, as well early spectroscopy, suggest that such CSM present more often than previously expected. If true, this should also affect features SBO. We exploration impact interaction on width and luminosity using both analytic numerical modeling, where we parameterize steady-state wind. then compare PS1-13arp, SN showed UV excess has been argued in CSM. find PS1-13arp fit wind mass ∼0.08 M ⊙ radius ∼1900 R , parameters which are similar to, if not slightly less massive than, what have inferred for Type II SNe modeling. This similarity suggests future observations easier obtain appreciated.