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

The gravitational wave event GW170817 with a macronova/kilonova shows that amerger of two neutron stars ejects matter with radioactivity including$r$-process nucleosynthesis. A part of the ejecta inevitably falls back to thecentral object, possibly powering long-lasting activities of a short gamma-rayburst (sGRB), such as extended and plateau emissions. We investigate thefallback accretion with the $r$-process heating by performing one-dimensionalhydrodynamic simulations and developing a semi-analytical model. We show thatthe usual fallback rate $dM/dt \propto t^{-5/3}$ is halted by the heatingbecause pressure gradients accelerate ejecta beyond an escape velocity. Thesuppression is steeper than Chevalier's power-law model through Bondi accretionwithin a turn-around radius. The characteristic halting timescale is $\sim10^5$--$10^9$ sec for the GW170817-like $r$-process heating, which is longenough to continue the long-lasting emission of sGRBs. The halting timescale issensitive to the uncertainty of the $r$-process. Future observation of fallbackhalting could constrain the $r$-process heating on the year scale.

Fallback Accretion Halted by R-process Heating in Neutron Star Mergers and Gamma-Ray Bursts