Cosmological Blastwaves and the Intergalactic Medium

Abstract

Winds from protogalactic starbursts and quasars can drive shocks that heat, ionize, and enrich the intergalactic medium. The Sedov-Taylor solution for point-like explosions adequately describes these blastwaves early in their development, but as the time since the explosion ($t - t_1$) approaches the age of the universe ($t$), cosmological effects begin to alter the blastwave&#39;s structure and growth rate. This paper presents an analytical solution for adiabatic blastwaves in an expanding universe, valid when the IGM is homogeneous and contains only a small fraction of the total mass density ($Ω_{\rm IGM} << Ω_0$). Using this analytical solution, we examine the role protogalactic explosions might play in determining the state of intergalactic gas at $z \sim 2 - 4$.