| Speaker: | Sergei Blinnikov (ITEP) |
|---|---|
| Title: | Supernova shocks in circumstellar medium: from puzzles to cosmological tools. |
| Date (JST): | Wed, Feb 08, 2012, 15:30 - 17:00 |
| Place: | Lecture Hall |
| Related File: | 620.pdf |
| Abstract: |
The first powerful burst of photon radiation in a supernova appears when the shock front is a few photon mean-free paths below the star photosphere. This is called the shock breakout and is the first observable event after the neutrino and gravitational wave bursts in core-collapsing supernovae. Any early information about collapse is vitally important for understanding the physics of explosion, for constraining presupernovae, etc. While there is no hope to observe a neutrino burst outside the local group of galaxies, and the prospects of real observations of gravitational waves are not clear yet, the shock breakouts can be observed already now, several events per night, in the field of view of Subaru telescope. Now we witness direct observations of shock breakouts in extremely interesting events like XRF080109-SN2008D. I will discuss some puzzles related to this object. The theory must be developed here and this may lead eventually to better understanding of presupernova environments and physics of strong shocks like diffusive particle acceleration. I will discuss also prospects of discoveries of shock breakouts in the most numerous supernovae of type II at cosmological distances which can be a powerful means to measure the rate of core collapses and hence the star formation rate. Finally, I describe our current understanding of the most luminous subtype II supernovae (SNIIn with narrow lines in spectra) which manifest pulsational pair-instability of massive stars. The potential use of their long living radiative shocks as a tool for measuring distances and cosmological parameters without invoking the cosmological distance ladder will be discussed. |
| Contact: | Prof. Nomoto |
| Seminar Video: | [VIDEO] |
