The Type IIP Supernova 2012aw in M95: hydrodynamical modelling of the photospheric phase from accurate spectrophotometric monitoring

摘要

We present an extensive optical and near-infrared photometric andspectroscopic campaign of the type IIP supernova SN 2012aw. The dataset denselycovers the evolution of SN 2012aw shortly after the explosion up to the end ofthe photospheric phase, with two additional photometric observations collectedduring the nebular phase, to fit the radioactive tail and estimate the$^{56}$Ni mass. Also included in our analysis is the already published\textit{Swift} UV data, therefore providing a complete view of theultraviolet-optical-infrared evolution of the photospheric phase. On the basisof our dataset, we estimate all the relevant physical parameters of SN 2012awwith our radiation-hydrodynamics code: envelope mass $M_{env} \sim 20 M_\odot$,progenitor radius $R \sim 3 \times 10^{13}$ cm ($ \sim 430 R_\odot$), explosionenergy $E \sim 1.5$ foe, and initial $^{56}$Ni mass $\sim 0.06$ $M_\odot$.These mass and radius values are reasonably well supported by independentevolutionary models of the progenitor, and may suggest a progenitor mass higherthan the observational limit of $16.5 \pm 1.5 M_\odot$ of the Type IIP events.