English
Related papers

Related papers: The Convective Urca Process with Implicit Two-Dime…

200 papers

The previous analysis of the convective Urca neutrino loss process in degenerate, convective, quasi-static, carbon-burning cores by Barkat and Wheeler omitted specific consideration of the role of the kinetic energy flux. The arguments of…

Astrophysics · Physics 2009-10-31 J. Stein , Z. Barkat , J. C. Wheeler

A proposed setting for thermonuclear (Type Ia) supernovae is a white dwarf that has gained mass from a companion to the point of carbon ignition in the core. In the early stages of carbon burning, called the simmering phase, energy released…

Solar and Stellar Astrophysics · Physics 2025-01-29 Brendan Boyd , Alan Calder , Dean Townsley , Michael Zingale

A proposed setting for thermonuclear (Type Ia) supernovae is a white dwarf that has gained mass from a companion to the point of carbon ignition in the core. There is a simmering phase in the early stages of burning that involves the…

Solar and Stellar Astrophysics · Physics 2024-04-26 Brendan Boyd , Alexander Smith Clark , Alan C. Calder , Dean M. Townsley , Michael Zingale

We derive a new formalism for convective motions involving two radial flows. This formalism provides a framework for convective models that guarantees consistency for the chemistry and the energy budget in the flows, allows time-dependence…

Astrophysics · Physics 2009-11-10 P. Lesaffre , Ph. Podsiadlowski , C. A. Tout

Type Ia supernovae are bright thermonuclear explosions that are important to numerous areas of astronomy. However, the origins of these events are poorly understood. One proposed setting is that of a near Chandrasekhar mass white dwarf that…

Solar and Stellar Astrophysics · Physics 2026-04-07 Ferran Poca-Amorós , Brendan Boyd , Dean M. Townsley , Alan Calder

One possible fate of an accreting white dwarf is explosion in a type Ia supernova. However, the route to the thermonuclear runaway has always been uncertain owing to the lack of a convective model consistent with the Urca process. We derive…

Astrophysics · Physics 2016-08-30 P. Lesaffre , Ph. Podsiadlowski , C. A. Tout

Type Ia supernovae are bright thermonuclear explosions of one or more white dwarf stars. The exact origin and explosion mechanism for these supernovae is still poorly understood. In the near-Chandrasekhar mass progenitor model, a simmering…

Solar and Stellar Astrophysics · Physics 2026-05-20 Brendan Boyd , Ferran Poca-Amorós , Alan Calder , Dean M. Townsley

The neutron excess at the time of explosion provides a powerful discriminant among models of Type Ia supernovae. Recent calculations of the carbon simmering phase in single degenerate progenitors have disagreed about the final neutron…

High Energy Astrophysical Phenomena · Physics 2017-12-27 Josiah Schwab , Héctor Martínez-Rodríguez , Anthony L. Piro , Carles Badenes

We show that the direct Urca process of neutrino emission is allowed in two possible phases of nonspherical nuclei (inverse cylinders and inverse spheres) in the mantle of a neutron star near the crust-core interface. The process is open…

Astrophysics · Physics 2009-11-10 M. E. Gusakov , D. G. Yakovlev , P. Haensel , O. Y. Gnedin

We couple two-dimensional hydrodynamics to detailed one-dimensional multigroup flux-limited diffusion neutrino transport to investigate prompt convection in core collapse supernovae. Our initial conditions, time-dependent boundary…

Charged current neutrino-nucleon reactions, generally called Urca processes, are crucial actors of a neutron star's thermal evolution. The so-called direct processes show a pronounced threshold under which the reaction is kinematically…

Nuclear Theory · Physics 2026-01-12 Lami Suleiman , Micaela Oertel , Marco Mancini

Hydrodynamic simulations of neutron star mergers rely on the clear separation between the strong-interaction, weak-interaction, and hydrodynamic timescales. In this effective framework, weak Urca interactions are typically the slowest…

High Energy Astrophysical Phenomena · Physics 2026-03-17 Jamie M. Karthein , Maneesha Sushama Pradeep , Rachel Steinhorst

Shell convection driven by nuclear burning in a stellar core is a common hydrodynamic event in the evolution of many types of stars. We encounter and simulate this convection (i) in the helium core of a low-mass red giant during core helium…

Solar and Stellar Astrophysics · Physics 2015-05-27 Miroslav Mocak , Ewald Muller , Lionel Siess

Convective dissolution is the process by which CO$_2$ injected in deep geological formations dissolves into the aqueous phase, which allows storing it perennially by gravity. The process results from buoyancy-coupled Darcy flow and solute…

Fluid Dynamics · Physics 2022-07-06 Jayabrata Dhar , Patrice Meunier , François Nadal , Yves Méheust

We study the bulk viscosity in neutron star cores due to modified Urca processes involving nucleons, electrons and muons and analize its reduction by singlet-state or triplet-state superfluidity of nucleons. In combination with the results…

Astrophysics · Physics 2009-11-06 P. Haensel , K. P. Levenfish , D. G. Yakovlev

We calculate modified Urca neutrino emission rates in the dense nuclear matter in neutron star cores. We find that these rates are strongly enhanced in the beta-stable matter in regions of the core close to the direct Urca process…

High Energy Astrophysical Phenomena · Physics 2018-09-25 P. S. Shternin , M. Baldo , P. Haensel

We present results from high-resolution semi-global simulations of neutrino-driven convection in core-collapse supernovae. We employ an idealized setup with parametrized neutrino heating/cooling and nuclear dissociation at the shock front.…

High Energy Astrophysical Phenomena · Physics 2016-04-06 David Radice , Christian D. Ott , Ernazar Abdikamalov , Sean M. Couch , Roland Haas , Erik Schnetter

Planetary atmospheres are commonly thought to result from the efficient outgassing of cooling magma oceans. During this stage, vigorous convective motions in the molten interior are believed to rapidly transport the dissolved volatiles to…

Earth and Planetary Astrophysics · Physics 2022-09-14 Arnaud Salvador , Henri Samuel

The bulk viscosity of the neutron star matter due to the direct Urca processes involving nucleons, electrons and muons is studied taking into account possible superfluidity of nucleons in the neutron star cores. The cases of singlet-state…

Astrophysics · Physics 2009-05-13 P. Haensel , K. P. Levenfish , D. G. Yakovlev

A toy model of the post-shock region of core-collapse supernovae is used to study the non-linear development of turbulent motions driven by convection in the presence of advection. Our numerical simulations indicate that buoyant…

Solar and Stellar Astrophysics · Physics 2018-07-18 Rémi Kazeroni , Brendan K. Krueger , Jérôme Guilet , Thierry Foglizzo , Daniel Pomarède
‹ Prev 1 2 3 10 Next ›