Astro Seminar - Self-similarity of the third type in ultra-relativistic blastwaves скачать в хорошем качестве

Astro Seminar - Self-similarity of the third type in ultra-relativistic blastwaves

Astro Seminar - Self-similarity of the third type in ultra-relativistic blastwaves Tamar Faran, Weizmann Institute Abstract: I will introduce a new class of self-similar solutions that emerge in the problem of relativistic explosions. Consider an ultra-relativistic shock wave propagating in a power-law density profile of the form rho ~ z^{-k}. Self-similar solutions of the first kind can be found for k less than 7/4 using dimensional considerations. For steeper density gradients with k large than 2, second type solutions are obtained by solving an eigen value problem. However, for intermediate power-law indices 7/4 less than k less than 2, the flow does not obey any of the known types of self-similarity. Instead, the solutions belong to a new class in which the self-similar dynamics are dictated by the non-self-similar part of the flow. I will give a brief introduction to self-similar solutions and discuss the three classes — types I, II, II in the context of Newtonian and ultra relativistic blast waves.