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

Macronovae (kilonovae) that arise in binary neutron star mergers are poweredby radioactive beta decay of hundreds of $r$-process nuclides. We derive, usingFermi's theory of beta decay, an analytic estimate of the nuclear heating rate.We show that the heating rate evolves as a power law ranging between $t^{-6/5}$to $t^{-4/3}$. The overall magnitude of the heating rate is determined by themean values of nuclear quantities, e.g., the nuclear matrix elements of betadecay. These values are specified by using nuclear experimental data. Wediscuss the role of higher order beta transitions and the robustness of thepower law. The robust and simple form of the heating rate suggests thatobservations of the late-time bolometric light curve $\propto t^{-\frac{4}{3}}$would be a direct evidence of a $r$-process driven macronova. Such observationscould also enable us to estimate the total amount of $r$-process nucleiproduced in the merger.

Analytic heating rate of neutron star merger ejecta derived from Fermi's theory of beta decay