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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

In this {\it Letter}, we present the result of an axisymmetric CCSNsimulation conducted with appropriate treatments of neutrino transport andproper motions of proto-neutron star (PNS), in which a remarkable PNSacceleration is observed in association with asymmetric neutrino emissions bythe time of $300$ms after bounce. We find that these asymmetric neutrinoemissions play important roles in the acceleration of PNS in this phase. Thecorrelation between the PNS proper motion and the asymmetric ejecta is similarto that in the neutron star (NS) kick of hydrodynamic origin. Bothelectron-type neutrinos ($\nu_{\rm e}$) and their anti-particles($\bar{\nu}_{\rm e}$) have $\sim 10\%$ level of asymmetry between the northernand southern hemispheres, while other heavy-leptonic neutrinos ($\nu_x$) havemuch smaller asymmetry of $\sim 1 \%$. The emissions of $\bar{\nu}_{\rm e}$ and$\nu_x$ are higher in the hemisphere of stronger shock expansion whereas the$\nu_{\rm e}$ emission is enhanced in the opposite hemisphere: in total theneutrinos carry some linear momentum to the hemisphere of the stronger shockexpansion. The asymmetry is attributed to the non-spherical distribution ofelectron-fraction ($Y_e$) in the envelope of PNS. Although it is similar toLESA (lepton-emission self-sustained asymmetry), the $Y_e$ asymmetry seems tobe associated with the PNS motion: the latter triggers lateral circular motionsin the envelope of PNS by breaking symmetry of the matter distribution there,which are then sustained by a combination of convection, lateral neutrinodiffusion and matter-pressure gradient. Our findings may have an influence onthe current theories on the NS kick mechanism although long-term simulationsare required to assess their impact on the later evolution.

Possible early linear acceleration of proto-neutron stars via asymmetric neutrino emission in core-collapse supernovae