Date:
Tue, 27/11/201212:30-13:30
"Light curves following shock breakout through a thick wind"
Abstract:
Recent supernovae (SNe) detections have motivated renewed interest in SN shock breakouts from stars surrounded by thick winds, including predictions of observable hard X-rays. Wind breakouts on timescales of a day or longer are currently the most probable for detection. I will talk about the signal that follows such events, starting from the breakout of the radiation mediated shock and tracing the evolution of the collisionless shock which forms afterwards. Describing the collisionless shock evolution I will focus on cases where the breakout itself is in thermal equilibrium, peaking in optical/UV. In these cases the post-breakout emission contains two spectral components - soft (optical/UV) and hard (X-rays/soft gamma-rays). During the breakout the luminosity is dominated by the soft component and the temperature can vary significantly from one event to another (10^4-10^6 K), where events with longer breakout time, t_bo, are generally softer. The hard component carries a small fraction of the breakout emission, and its fraction of the total luminosity rises quickly afterwards, gaining dominance at ~10-50 t_bo. The spectral evolution depends mostly on the breakout time. In terms of prospects for X-ray detections, it is best to observe 100-500 days after explosions with breakout timescales between a week and a month.
Abstract:
Recent supernovae (SNe) detections have motivated renewed interest in SN shock breakouts from stars surrounded by thick winds, including predictions of observable hard X-rays. Wind breakouts on timescales of a day or longer are currently the most probable for detection. I will talk about the signal that follows such events, starting from the breakout of the radiation mediated shock and tracing the evolution of the collisionless shock which forms afterwards. Describing the collisionless shock evolution I will focus on cases where the breakout itself is in thermal equilibrium, peaking in optical/UV. In these cases the post-breakout emission contains two spectral components - soft (optical/UV) and hard (X-rays/soft gamma-rays). During the breakout the luminosity is dominated by the soft component and the temperature can vary significantly from one event to another (10^4-10^6 K), where events with longer breakout time, t_bo, are generally softer. The hard component carries a small fraction of the breakout emission, and its fraction of the total luminosity rises quickly afterwards, gaining dominance at ~10-50 t_bo. The spectral evolution depends mostly on the breakout time. In terms of prospects for X-ray detections, it is best to observe 100-500 days after explosions with breakout timescales between a week and a month.