English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We perform a detailed study on the dynamics of a relativistic blast wave withthe presence of a long-lived reverse shock (RS). Although a short-lived RS hasbeen widely considered, the RS is believed to be long-lived as a consequence ofa stratification expected on the ejecta Lorentz factors. The existence of along-lived RS makes the forward shock (FS) dynamics to deviate from aself-similar Blandford-McKee solution. Employing the "mechanical model" thatcorrectly incorporates the energy conservation, we present an accurate solutionfor both the FS and RS dynamics. We conduct a sophisticated calculation of theafterglow emission. Adopting a Lagrangian description of the blast wave, wekeep track of an adiabatic evolution of numerous shells between the FS and RS.An evolution of the electron spectrum is also followed individually for everyshell. We then find the FS and RS light curves by integrating over the entireFS and RS shocked regions, respectively. In particular, we make use of ananalytic expression for observed spectral flux, which we derive here in termsof an observed frequency and observer time. Exploring a total of 20 differentejecta stratifications, we explain in detail how a stratified ejecta affectsits blast wave dynamics and afterglow light curves. We show that, while the FSlight curves are not sensitive to the ejecta stratifications, the RS lightcurves exhibit much richer features, including steep declines, plateaus, bumps,re-brightenings, and a variety of temporal decay indices. These distinctive RSfeatures may be observable if the RS has higher values of the micophysicsparameters than the FS. We discuss possible applications of our results inunderstanding the GRB afterglow data.

Dynamics and Afterglow Light Curves of GRB Blast Waves with a Long-lived Reverse Shock