English
Related papers

Related papers: Stellarators close to quasisymmetry

200 papers

The spin-up of a neutron star crucially depends on the maximum orbital frequency around it, as do a host of other high energy accretion phenomena in low mass X-ray binaries, including quasi-periodic oscillations (QPOs) in the X-ray flux. We…

Astrophysics · Physics 2007-05-23 D. Gondek-Rosinska , W. Kluzniak

Fast rotation seems to be the major factor to trigger the Be phenomenon. Surface fast rotation can be favored by initial formation conditions such as metal abundance. Models of fast rotating atmospheres and evolutionary tracks are used to…

Astrophysics · Physics 2007-05-23 Ronaldo Levenhagen , Nelson Vani Leister , Juan Zorec , Yves Fremat

Quasisymmetry is an unusual symmetry that can be present in toroidal magnetic fields, enabling confinement of charged particles and plasma. Here it is shown that both quasi-axisymmetry and quasi-helical symmetry can be achieved to a much…

Plasma Physics · Physics 2022-02-02 Matt Landreman , Elizabeth Paul

Axisymmetric pulsations of rotating neutron stars can be excited in several scenarios, such as core-collapse, crust and core-quakes and binary mergers and could become detectable either in gravitational waves or high-energy radiation. Here,…

Astrophysics · Physics 2009-10-31 Jose A. Font , Harald Dimmelmeier , Anshu Gupta , Nikolaos Stergioulas

This is the first of two papers about collisionless, electrostatic micro-instabilities in stellarators, with an emphasis on trapped-particle modes. It is found that, in so-called maximum-$J$ configurations, trapped-particle instabilities…

Plasma Physics · Physics 2015-06-17 P. Helander , J. H. E. Proll , G. G. Plunk

In this paper, we present the results of 3-dimensional collapse simulations of rotating stars for a range of stellar progenitors. We find that for the fastest spinning stars, rotation does indeed modify the convection above the…

Astrophysics · Physics 2009-11-10 C. L. Fryer , M. S. Warren

Observations show that faster-rotating stars tend to have stronger magnetic activity and shorter magnetic cycles. The cyclical magnetic activity of the Sun and stars is believed to be driven by the dynamo process. The success of the…

Solar and Stellar Astrophysics · Physics 2024-06-05 Zebin Zhang , Jie Jiang , Leonid Kitchatinov

We compare the current effects of rotation in stellar evolution to those of the magnetic field created by the Tayler instability. In stellar regions, where magnetic field can be generated by the dynamo due to differential rotation (Spruit…

Astrophysics · Physics 2009-11-10 Andre Maeder , Georges Meynet

We have computed models of rotating relativistic stars with a toroidal magnetic field and investigated the combined effects of magnetic field and rotation on the apparent shape (i.e. the surface deformation), which could be relevant for the…

General Relativity and Quantum Cosmology · Physics 2014-02-14 Joachim Frieben , Luciano Rezzolla

We perform fully relativistic calculations of binary neutron stars in corotating, circular orbit. While Newtonian gravity allows for a strict equilibrium, a relativistic binary system emits gravitational radiation, causing the system to…

General Relativity and Quantum Cosmology · Physics 2016-08-25 T. W. Baumgarte , G. B. Cook , M. A. Scheel , S. L. Shapiro , S. A. Teukolsky

Angular momentum is a key property regulating star formation and evolution. However, the physics driving the distribution of the stellar rotation rates of early-type main-sequence stars is as yet poorly understood. Using our catalog of…

Solar and Stellar Astrophysics · Physics 2021-11-24 Weijia Sun , Xiao-Wei Duan , Licai Deng , Richard de Grijs

We continue our studies on stellar latitudinal differential rotation. The presented work is a sequel of the work of Reiners et al. who studied the spectral line broadening profile of hundreds of stars of spectral types A through G at high…

Solar and Stellar Astrophysics · Physics 2010-10-29 Matthias~Ammler von Eiff , Ansgar Reiners

We discuss three specific modes of accretion disks around rotating magnetized neutron stars which may explain the separations of the kilo Hertz quasi periodic oscillations (QPO) seen in low mass X-ray binaries. The existence of these modes…

Astrophysics · Physics 2009-11-13 R. V. E. Lovelace , M. M. Romanova

Context: Rotation plays a key role in the life cycles of stars with masses above 8 Msun. Hence, accurate knowledge of the rotation rates of such massive stars is critical for understanding their properties and for constraining models of…

Solar and Stellar Astrophysics · Physics 2015-06-17 J. O. Sundqvist , S. Simon-Diaz , J. Puls , N. Markova

We take advantage of interferometric measurements of Achernar to inquire on its internal rotational law. The reinterpretation of interferome-tric data and the use of fundamental parameters corrected for gravitational darkening effects and…

Astrophysics · Physics 2007-05-23 Juan Zorec , Armando Domiciano De Souza , Yves Fremat , Farok Vakli

Non-axisymmetric oscillations of differentially rotating stars are studied using both slow rotation and Cowling approximation. The equilibrium stellar models are relativistic polytropes where differential rotation is described by the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Andrea Passamonti , Adamantios Stavridis , Kostas Kokkotas

Rotation is thought to be a major factor in the evolution of massive stars, especially at low metallicity, with consequences for their chemical yields, ionizing flux and final fate. Determining the natal rotation-rate distribution of stars…

Solar and Stellar Astrophysics · Physics 2015-06-12 S. E. de Mink , N. Langer , R. G. Izzard , H. Sana , A. de Koter

We study the synchrotron radiation emitted by a charged fermion, rotating as a part of a larger system, in a constant magnetic field $B$ parallel to the axis of rotation. The rotation is classical and independent of the magnetic field. The…

High Energy Physics - Phenomenology · Physics 2023-06-21 Matteo Buzzegoli , Jonathan D. Kroth , Kirill Tuchin , Nandagopal Vijayakumar

We describe sophisticated new Bayesian analysis methods that make it possible to estimate quickly the masses and radii of rapidly rotating, oblate neutron stars by fitting oblate-star waveform models to energy-resolved observations of the…

High Energy Astrophysical Phenomena · Physics 2015-08-06 M. Coleman Miller , Frederick K. Lamb

We present results of a study comparing the relative velocity of $\rm Ly\alpha$ absorbers to the rotation velocity of nearby galaxy disks in the local universe ($z \leq 0.03$). We have obtained rotation curves via long-slit spectroscopy of…

Astrophysics of Galaxies · Physics 2020-07-22 David M. French , Bart P. Wakker
‹ Prev 1 3 4 5 6 7 10 Next ›