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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The two leading interpretations of achromatic breaks that are observed in thelight curves of GRBs afterglow are (i) the manifestation of the edge of a jet,which has a roughly uniform energy profile and a sharp edge and (ii) a line ofsight effect in jets with a variable energy profile. The first scenariorequires the inner engine to produce a jet with a different opening angle eachexplosion, while the latter requires a standard engine. The physical structureof the jet is a crucial factor in understanding GRB progenitors, and thereforediscriminating the two jet scenarios is particularly relevant. In thestructured jet case, specific predictions can be made for the distribution ofobserved break angles $\theta_{\rm break}$, while that distribution isarbitrary in the first scenario. We derive the theoretical distribution for thestructured jet model. Specifically, we predict the most common angle to beabout 0.12 rad, in rough agreement with the sample. If this agreement wouldhold as the sample size increases, it would strengthen the case for thestandard jet hypothesis. We show that a prediction of this model is that theaverage viewing angle is an increasing function of the survey sensitivity, andin particular that a mission like {\em Swift} will find the typical viewingangle to be about 0.3 rad. The local event rate predicted by this model is$R_{\rm GRB}(z=0)\sim 0.5 $ Gpc$^{-3}$ yr$^{-1}$.Comment: 14 pages, 3 figures; accepted to Ap

Jets in Gamma‐Ray Bursts: Tests and Predictions for the Structured Jet Model