Reverberation of pulsar wind nebulae – II. Anatomy of the ‘thin-shell’ evolution

During its early evolution, a pulsar wind nebula (PWN) sweeps the inner part of supernova ejecta and forms thin massive shell. Later on, when shell has been reached by reverse shock remnant, evolution becomes more complex, in most cases reverting expansion into compression: this later phase is called "reverberation". Computations done so far to understand have mostly performed thin-shell approximation, where PWN radius assimilated that swept-up under effect both pressure from PWN, outer remnant. Despite approach seems rather justifiable, implementations inaccurate, correctness, never tested. The was naively assumed be scaled according Sedov solution (or constant fraction it) along entire evolution. assumption itself fails process, being no longer comparison with size PWN. Here, through combination numerical models, dimensional arguments, analytic approximations, we present detailed analysis interaction We provide new approximation pressure, beyond solution, revised "thin-shell" able reproduce results simulations. Finally, compute efficiency which compressed during reverberation over wide population sources.