Mass-loss histories of Type IIn supernova progenitors within decades before their explosion

Abstract

We present results of a systematic study of the mass-loss properties of Type\nIIn supernova progenitors within decades before their explosion. We apply an\nanalytic light curve model to 11 Type IIn supernova bolometric light curves to\nderive the circumstellar medium properties. We reconstruct the mass-loss\nhistories based on the estimated circumstellar medium properties. The estimated\nmass-loss rates are mostly higher than 1e-3 Msun/yr and they are consistent\nwith those obtained by other methods. The mass-loss rates are often found to be\nconstantly high within decades before their explosion. This indicates that\nthere exists some mechanism to sustain the high mass-loss rates of Type IIn\nsupernova progenitors for at least decades before their explosion. Thus, the\nshorter eruptive mass loss events observed in some Type IIn supernova\nprogenitors are not always responsible for creating their dense circumstellar\nmedia. In addition, we find that Type IIn supernova progenitors may tend to\nincrease their mass-loss rates as they approach to the time of their explosion.\nWe also show a detailed comparison between our analytic prediction and\nnumerical results.\n