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Related papers: Mean-field dynamo action in protoneutron stars

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Star formation is enhanced in spiral arms because of a combination of orbit crowding, cloud collisions, and gravitational instabilities. The characteristic mass for the instability is 10^7 Msun in gas and 10^5 Msun in stars, and the…

Astrophysics · Physics 2015-05-13 Bruce G. Elmegreen

Nonlinear mean-field models of the solar dynamo show long-term variability, which may be relevant to different states of activity inferred from long-term radiocarbon data. This paper is aimed to probe the dynamo hysteresis predicted by the…

Solar and Stellar Astrophysics · Physics 2015-04-24 Bidya Binay Karak , Leonid L. Kitchatinov , Axel Brandenburg

In a previous paper [M. E. Gusakov, A. I. Chugunov, and E. M. Kantor, Phys. Rev. Lett. 112, 151101 (2014)], we introduced a new scenario that explains the existence of rapidly rotating warm neutron stars (NSs) observed in low-mass X-ray…

Solar and Stellar Astrophysics · Physics 2015-06-16 Mikhail E. Gusakov , Andrey I. Chugunov , Elena M. Kantor

We describe how the nonlinear development of the R mode instability of neutron stars influences spin up to millisecond periods via accretion. Our arguments are based on nearly-resonant interactions of the R mode with pairs of "daughter…

Solar and Stellar Astrophysics · Physics 2013-10-30 Ruxandra Bondarescu , Ira Wasserman

In solar-type stars (with radiative cores and convective envelopes), the magnetic field powers star spots, flares and other solar phenomena, as well as chromospheric and coronal emission at ultraviolet to X-ray wavelengths. The dynamo…

Solar and Stellar Astrophysics · Physics 2016-08-17 Nicholas J. Wright , Jeremy J. Drake

The rotation-activity connection explains stellar activity in terms of rotation and convective overturn time. It is well established in stars of spectral types F--K and in M-type stars of young clusters. It is not established in field…

Astrophysics · Physics 2009-11-13 Ansgar Reiners

We present new results of a stability analysis of realistic models of post-extreme horizontal branch stars. We find that g-mode instabilities develop in some of these models as a result of a potent epsilon-mechanism associated with the…

Astrophysics · Physics 2009-10-30 S. Charpinet , G. Fontaine , P. Brassard , B. Dorman

The periods of magnetic activity cycles in the Sun and solar-type stars do not exhibit a simple or even single trend with respect to rotation rate or luminosity. Dynamo models can be used to interpret this diversity, and can ultimately help…

Solar and Stellar Astrophysics · Physics 2018-08-15 A. Strugarek , P. Beaudoin , P. Charbonneau , A. S. Brun

This paper introduces a new empirical model for the rotational evolution of Sun-like stars -- those with surface convection zones and non-convective interior regions. Previous models do not match the morphology of observed (rotation…

Solar and Stellar Astrophysics · Physics 2015-06-19 Timothy M. Brown

First results of numerical simulations are presented which compute the dynamical evolution of a neutron star with a mass slightly below the minimum stable mass by means of a new implicit (general relativistic) hydrodynamic code. We show…

Astrophysics · Physics 2007-05-23 K. Sumiyoshi , S. Yamada , H. Suzuki , W. Hillebrandt

Major photometric monitoring campaigns of star-forming regions in the past decade have provided rich rotation period distributions of pre-main-sequence stars. The rotation periods span more than an order of magnitude in period, with most…

Astrophysics · Physics 2007-05-23 Robert D. Mathieu

We analyze the normal phase of the attractive Hubbard model within dynamical mean-field-theory. We present results for the pair-density, the spin-susceptibility, the specific heat, the momentum distribution, and for the quasiparticle…

Strongly Correlated Electrons · Physics 2007-05-23 M. Keller , W. Metzner , U. Schollwoeck

The overstability of the fundamental radial mode in M dwarf models was theoretically predicted by Rodr\'iguez-L\'opez et al. (2012). The periods were found to be in the ranges ~25-40 min and ~4-8 h, depending on stellar age and excitation…

Solar and Stellar Astrophysics · Physics 2015-06-18 C. Rodríguez-López , J. MacDonald , P. J. Amado , A. Moya , D. Mullan

The dynamics of disordered nuclear spin ensembles are the subject of nuclear magnetic resonance studies. Due to the through-space long-range dipolar interaction generically many spins are involved in the time evolution, so that exact brute…

Materials Science · Physics 2026-05-11 Timo Gräßer , Götz S. Uhrig , Matthias Ernst

Observations of radio pulsars have revealed that they have large velocities which may be greater than 1000 km/s. In this work, the efficacy of an active-sterile neutrino transformation mechanism to provide these large pulsar kicks is…

High Energy Astrophysical Phenomena · Physics 2011-06-20 Chad T. Kishimoto

The Tayler-Spruit dynamo is one of the most promising mechanisms proposed to explain angular momentum transport during stellar evolution. Its development in proto-neutron stars spun-up by supernova fallback has also been put forward as a…

High Energy Astrophysical Phenomena · Physics 2023-08-29 Paul Barrère , Jérôme Guilet , Raphaël Raynaud , Alexis Reboul-Salze

[Abridged abstract:] Stellar activity data provide evidence of activity wave branches propagating polewards rather than equatorwards (the solar case). Stellar dynamo theory allows polewards propagating dynamo waves for certain governing…

Solar and Stellar Astrophysics · Physics 2015-05-28 D. Moss , D. Sokoloff , A. F. Lanza

M-dwarf stars are well known for the intense magnetic activity that many of them exhibit. In cool stars with near-surface convection zones, this magnetic activity is thought to be driven largely by the interplay of convection and the large…

Solar and Stellar Astrophysics · Physics 2022-03-30 Connor P. Bice , Juri Toomre

We derive the energy asymmetry given the proto-neutronstar during the time when the neutrino sphere is near the surface of the proto-neutron star, using the modified URCA process. The electrons produced with the anti-neutrinos are in Landau…

High Energy Physics - Phenomenology · Physics 2008-11-26 Leonard S. Kisslinger

Context: Convectively-driven flows play a crucial role in the dynamo processes that are responsible for producing magnetic activity in stars and planets. It is still not fully understood why many astrophysical magnetic fields have a…

Solar and Stellar Astrophysics · Physics 2018-05-09 P. J. Bushby , P. J. Käpylä , Y. Masada , A. Brandenburg , B. Favier , C. Guervilly , M. J. Käpylä
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