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Related papers: The convective Urca process

200 papers

Type Ia supernovae (SNe Ia) have been an important tool for astronomy for quite some time; however, the nature of their progenitors remains somewhat mysterious. Recent theoretical studies indicated the possibility of producing thermonuclear…

Solar and Stellar Astrophysics · Physics 2016-04-13 P. Neunteufel , S. -C. Yoon , N. Langer

The accretion of hydrogen-rich matter onto C/O and O/Ne white dwarfs in binary systems leads to unstable thermonuclear ignition of the accreted envelope, triggering a convective thermonuclear runaway and a subsequent classical, recurrent,…

Astrophysics · Physics 2011-02-11 Ken J. Shen , Lars Bildsten

Stellar evolution models predict the existence of hybrid white dwarfs (WDs) with a carbon-oxygen core surrounded by an oxygen-neon mantle. Being born with masses ~1.1 Msun, hybrid WDs in a binary system may easily approach the Chandrasekhar…

High Energy Astrophysical Phenomena · Physics 2015-05-18 M. Kromer , S. T. Ohlmann , R. Pakmor , A. J. Ruiter , W. Hillebrandt , K. S. Marquardt , F. K. Roepke , I. R. Seitenzahl , S. A. Sim , S. Taubenberger

Three-dimensional (3D), time dependent numerical simulations, of flow of matter in stars, now have sufficient resolution to be fully turbulent. The late stages of the evolution of massive stars, leading up to core collapse to a neutron star…

Solar and Stellar Astrophysics · Physics 2014-01-30 W. David Arnett , Casey Meakin , Maxime Viallet

White dwarfs are stellar embers depleted of nuclear energy sources that cool over billions of years. These stars, which are supported by electron degeneracy pressure, reach densities of 1e7 grams per cubic centimetre in their cores. It has…

Type Ia supernovae (SNIa) are thermonuclear explosions of white dwarfs in binary systems. They are central to galactic chemical evolution and serve as standardizable candles in cosmology, yet their progenitors remain uncertain. In this…

We apply our recently suggested statistical approach to thermal evolution of isolated neutron stars and accreting quasistationary neutron stars in X-ray transients for constraining the position and relative broadening alpha of the direct…

Solar and Stellar Astrophysics · Physics 2015-07-19 M. V. Beznogov , D. G. Yakovlev

We analyze the evolution of binary stars to calculate synthetic rates and delay times of the most promising Type Ia Supernovae progenitors. We present and discuss evolutionary scenarios in which a white dwarf reaches the Chandrasekhar-mass…

Solar and Stellar Astrophysics · Physics 2010-05-27 Ashley J. Ruiter , Krzysztof Belczynski , Chris L. Fryer

We discuss the first available binary evolution models which include up-to-date rotational physics for both components, as well as angular momentum accretion and spin-orbit coupling. These models allow a self-consistent computation of the…

Astrophysics · Physics 2007-05-23 N. Langer , S. -C. Yoon , J. Petrovic , A. Heger

For carbon-oxygen white dwarfs accreting hydrogen or helium at rates in the range ~1-10 x 10^(-8) Msun/y, a variety of explosive outcomes is possible well before the star reaches the Chandrasekhar mass. These outcomes are surveyed for a…

High Energy Astrophysical Phenomena · Physics 2015-05-20 S. E. Woosley , Daniel Kasen

1D stellar evolution calculations produce uncertain predictions for quantities like the age, core mass, core compactness, and nucleo-synthetic yields; a key source of uncertainty is the modeling of interfaces between regions that are…

The currently favored scenario for the progenitor evolution of Type Ia supernovae (SNe Ia) presumes that white dwarfs in close binary systems grow to the Chandrasekhar limit via mass accretion from their non-degenerate companions. However,…

Astrophysics · Physics 2009-11-10 Sung-Chul Yoon , Norbert Langer

We have carried out a detailed study of one of the most popular evolutionary channels for the production of Type Ia supernova (SN Ia) progenitors, the semi-degenerate channel (CO+MS), where a carbon/oxygen (CO) white dwarf (WD) accretes…

Astrophysics · Physics 2009-11-10 Zhanwen Han , Philipp Podsiadlowski

We present a large parameter study where we investigate the structure of white dwarf (WD) merger remnants after the dynamical phase. A wide range of WD masses and compositions are explored and we also probe the effect of different initial…

High Energy Astrophysical Phenomena · Physics 2015-06-16 M. Dan , S. Rosswog , M. Brueggen , P. Podsiadlowski

The evolution of binaries consisting of evolved main sequence stars (1 < M_d/Msun < 3.5) with white dwarf companions (0.7 < M_wd/Msun < 1.2) is investigated through the thermal mass transfer phase. Taking into account the stabilizing effect…

Astrophysics · Physics 2016-08-30 Natalia Ivanova , Ronald E. Taam

Close binaries consisting of a main sequence star and a white dwarf are considered as candidates for Type~Ia supernova progenitors. We present selfconsistent calculations of the time dependence of the structure of the main sequence star,…

Astrophysics · Physics 2007-05-23 N. Langer , A. Deutschmann , S. Wellstein , P. Hoeflich

It is shown that in presence of URCA shell pulsational energy losses due to neutrino emission and nonequilibrium beta heating are much less than energy losses by excitation of short-wavelength acoustic waves. Convective motion in presence…

Astrophysics · Physics 2007-05-23 G. S. Bisnovatyi-Kogan

In the standard Lambda cold dark matter paradigm, pure dark matter simulations predict dwarf galaxies should inhabit dark matter haloes with a centrally diverging density `cusp'. This is in conflict with observations that typically favour a…

The ultimate understanding of Type Ia Supernovae diversity is one of the most urgent issues to exploit thermonuclear explosions of accreted White Dwarfs (WDs) as cosmological yardsticks. In particular, we investigate the impact of the…

This is the second in a series of papers associated with cataclysmic variables (CVs) and related objects, formed in a suite of simulations for globular cluster evolution performed with the MOCCA Monte Carlo code. We study the properties of…

Astrophysics of Galaxies · Physics 2016-12-05 Diogo Belloni , Mirek Giersz , Helio J. Rocha-Pinto , Nathan Leigh , Abbas Askar