Following a suggestion that a directed relativistic explosion may have a universal intermediate asymptotic, we derive a self-similar solution for an ultra-relativistic jetted blast wave. The solution involves three distinct regions: an approximately paraboloid head where the Lorentz factor $γ$ exceeds $\sim1/2$ 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 towards the axis. Most ($\sim 80\%$) 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 $\sim 1/6$, $\sim1/4$, and $\sim3/4$ 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.
3D Hydrodynamic Simulations of Micro-Tidal Disruption Events Favor a Narrow, Ultra-relativistic Jet for GRB250702B
Northwestern University（西北大学）；University of Colorado（科罗拉多大学）；National Institute of Standards and Technology（美国国家标准与技术研究院）；University of California, San Diego（加州大学圣地亚哥分校）；Harvard & Smithsonian（哈佛大学与史密森尼学会）；Columbia University（哥伦比亚大学）；Flatiron Institute（平顿研究所）
Synchrotron Self-Compton Model of TeV Afterglows in Gamma-Ray Bursts
Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México（墨西哥国立自治大学射电天文学与天体物理研究所）；Department of Natural Sciences, The Open University of Israel（以色列开放大学自然科学系）；Astrophysics Research Center of the Open university (ARCO), The Open University of Israel（以色列开放大学天体物理学研究中心）；Department of Physics, The George Washington University（乔治华盛顿大学物理系）
Ultra-long MeV transient from a relativistic jet: a tidal disruption event candidate
Gran Sasso Science Institute（大萨索科学研究所）；INFN - Laboratori Nazionali del Gran Sasso（意大利国家核物理研究所-大萨索国家实验室）；Dublin Institute for Advanced Studies（都柏林高等研究院）；Yerevan State University（埃里温国立大学）；Indian Institute of Technology Indore（印度技术学院印多尔分校）；The Pennsylvania State University（宾夕法尼亚州立大学）
