Directed Relativistic Blast Wave

Understand

A spherically symmetrical ultra-relativistic blast wave is not an attractor of a generic asymmetric explosion.

• Spherical symmetry is reached only by the time the blast wave slows down to non-relativistic velocities, when the Sedov-Taylor-von Neumann attractor solution sets in.
• We show however, that a directed relativistic explosion, with the explosion momentum close to the explosion energy, produces a blast wave with a universal intermediate asymptotic -- a selfsimilar directed ultra-relativistic blast wave.
• This universality might be of interest for the astrophysics of gamma-ray burst afterglows.