Dynamics of Relativistic Shock Waves Subject to a Strong Radiation Drag: Similarity Solutions and Numerical Simulations

摘要

We examine the effect of Compton drag on the dynamics of a relativistic shockwave. Similarity solutions describing a radiation-supported shock are obtainedfor certain profiles of the external radiation intensity and the density of theunshocked ejecta, and are compared with 1D numerical simulations of a blastwave expanding into an ambient medium containing isotropic seed radiation. Boththe analytic model and the simulations indicate that under realistic conditionsthe radiation drag should strongly affect the dynamics and structure of theshocked layer. In particular, our calculations show significant strengtheningof the reverse shock and weakening of the forward shock over time of the orderof the inverse Compton cooling time. We conclude that the effect of radiationdrag on the evolution of the emitting plasma should affect the resultant lightcurves and, conceivably, spectra of the observed emission during strong blazarflares.