• DOI:10.1088/0004-637X/815/2/100
• Corpus ID: 118778134

SELF-SIMILAR ULTRARELATIVISTIC JETTED BLAST WAVE

@article{Keshet2015SELFSIMILARUJ,
  title={SELF-SIMILAR ULTRARELATIVISTIC JETTED BLAST WAVE},
  author={Uri Keshet and Dani Kogan},
  journal={The Astrophysical Journal},
  year={2015},
  volume={815}
}

• U. Keshet, D. Kogan
• Published 15 June 2015
• Physics
• The Astrophysical Journal

Following a suggestion that a directed relativistic explosion may have a universal intermediate asymptotic, we derive a self-similar solution for an ultrarelativistic jetted blast wave. The solution involves three distinct regions: an approximately paraboloid head where the Lorentz factor γ exceeds ∼ 1 / 2 ?> of its maximal, nose value; a geometrically self-similar, expanding envelope slightly narrower than a paraboloid; and an axial core in which the (cylindrically, henceforth) radial flow u ?> converges inward toward the axis. Most (∼80%) of the energy lies well beyond the leading, head region. Here, a radial cross section shows a maximal γ (separating the core and the envelope), a sign reversal in u ?> , and a minimal γ, at respectively ∼1/6, ∼1/4, and ∼3/4 of the shock radius. The solution is apparently unique, and approximately agrees with previous simulations, of different initial conditions, that resolved the head. This suggests that unlike a spherical relativistic blast wave, our solution is an attractor, and may thus describe directed blast waves such as in the external shock phase of a γ-ray burst.