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Related papers: Alfv\'{e}n wave mode conversion in pulsar magnetos…

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We study large-amplitude, very oblique Alfv\'en waves at low $\beta$, with small gradient length scales, comparable to the ion inertial scale $d_i$. Such waves have large density fluctuations, and slight dispersion from finite-frequency and…

Plasma Physics · Physics 2023-11-10 Alfred Mallet

The most common form of magnetar activity is short X-ray bursts, with durations from milliseconds to seconds, and luminosities ranging from $10^{36}$ to $10^{43}\ {\rm erg}\,{\rm s}^{-1}$. Recently, an X-ray burst from the galactic magnetar…

High Energy Astrophysical Phenomena · Physics 2022-08-02 Yajie Yuan , Andrei M. Beloborodov , Alexander Y. Chen , Yuri Levin , Elias R. Most , Alexander A. Philippov

We report the discovery of torsional Alfv\'enic oscillations in solar flares, which modulate the time evolution of the magnetic free energy $E_f(t)$, while the magnetic potential energy $E_p(t)$ is uncorrelated, and the nonpotential energy…

Solar and Stellar Astrophysics · Physics 2021-06-14 Markus J. Aschwanden , Tongjiang Wang

The 2016 Vela glitch observed by the Mt Pleasant radio telescope provides the first opportunity to study pulse-to-pulse dynamics of a pulsar glitch, opening up new possibilities to study the neutron star's interior. We fit models of the…

High Energy Astrophysical Phenomena · Physics 2019-07-03 Gregory Ashton , Paul D. Lasky , Vanessa Graber , Jim Palfreyman

We present the numerical simulations of winds from evolved giant stars using a fully non-linear, time dependent 2.5-dimensional magnetohydrodynamic (MHD) code. This study extends our previous fully non-linear MHD wind simulations to include…

Solar and Stellar Astrophysics · Physics 2015-05-19 Vladimir Airapetian , Kenneth G. Carpenter , Leon Ofman

Many cool stars possess complex magnetic fields [1] that are considered to undertake a central role in the structuring and energising of their atmospheres [2]. Alfv\'enic waves are thought to make a critical contribution to energy transfer…

Solar and Stellar Astrophysics · Physics 2019-02-12 R. J. Morton , M. Weberg , J. A. McLaughlin

The photospheric temperature minimum in the Sun and solar-like stars is very weakly ionized, with ionization fraction $f$ as low as $10^{-4}$. In galactic star forming regions, $f$ can be $10^{-10}$ or lower. Under these circumstances, the…

Solar and Stellar Astrophysics · Physics 2015-12-02 Paul S. Cally , Elena Khomenko

Recent observations have demonstrated that waves which are capable of carrying large amounts of energy are ubiquitous throughout the solar corona. However, the question of how this wave energy is dissipated (on which time and length scales)…

Solar and Stellar Astrophysics · Physics 2014-11-20 Jiajia Liu , Scott W. McIntosh , Ineke De Moortel , James Threlfall , Christian Bethge

We show that 5-minute acoustic oscillations may resonantly convert into Alfv{\'e}n waves in the $\beta{\sim}1$ region of the solar atmosphere. Considering the 5-minute oscillations as pumping standing acoustic waves oscillating along…

Astrophysics · Physics 2007-05-23 D. Kuridze , T. V. Zaqarashvili , B. Roberts

Context. Spacecraft measurements have shown Kinetic Alfv\'en Waves propagating in the terrestrial magnetosphere at lower wavenormal angles than predicted by linear Vlasov theory of electron-proton plasmas. To explain these observations, it…

Plasma Physics · Physics 2023-07-05 Nicolás Villarroel-Sepúlveda , Rodrigo A. López , Pablo S. Moya

Sunspots are intense regions of magnetic flux that are rooted deep below the photosphere. It is well established that sunspots host magnetohydrodynamic waves, with numerous observations showing a connection to the internal acoustic (or…

Solar and Stellar Astrophysics · Physics 2025-01-07 Hemanthi Miriyala , Richard J. Morton , Elena Khomenko , Patrick Antolin , Gert J. J. Botha

We performed one-dimensional force-free magnetodynamic numerical simulations of the propagation of Alfven waves along magnetic field lines around a spinning black-hole-like object, the Banados--Teitelboim--Zanelli black string, to…

High Energy Astrophysical Phenomena · Physics 2022-04-06 Shinji Koide , Sousuke Noda , Masaaki Takahashi , Yasusada Nambu

Modelling of adiabatic gravity wave propagation in the solar atmosphere showed that mode conversion to field guided acoustic waves or Alfv\'en waves was possible in the presence of highly inclined magnetic fields. This work aims to extend…

Solar and Stellar Astrophysics · Physics 2015-05-28 Marie E. Newington , Paul S. Cally

Using linear Vlasov theory of plasma waves and quasi-linear theory of resonant wave-particle interaction, the dispersion relations and the electromagnetic field fluctuations of fast and Alfven waves are studied for a low-beta multi-ion…

Solar and Stellar Astrophysics · Physics 2013-08-16 Ming Xiong , Xing Li

The six known highly dispersed fast radio bursts are attributed to extragalactic radio sources, of unknown origin but extremely energetic. We propose here a new explanation - not requiring an extreme release of energy - involving a body…

Earth and Planetary Astrophysics · Physics 2015-06-22 Fabrice Mottez , Philippe Zarka

The solar wind is found by Parker Solar Probe (PSP) to be abundant with Alfv\'enic velocity spikes and magnetic field kinks. Temperature enhancement is another remarkable feature associated with the Alfv\'enic spikes. How the prototype of…

Solar and Stellar Astrophysics · Physics 2023-01-11 Jiansen He , Xingyu Zhu , Liping Yang , Chuanpeng Hou , Die Duan , Lei Zhang , Ying Wang

M dwarf's atmosphere is expected to be highly magnetized. The magnetic energy can be responsible for heating the stellar chromosphere and corona, and driving the stellar wind. The nonlinear propagation of Alfv\'en wave is the promising…

Solar and Stellar Astrophysics · Physics 2021-09-29 Takahito Sakaue , Kazunari Shibata

Parker Solar Probe (PSP) observed sub-Alfvenic solar wind intervals during encounters 8 - 14, and low-frequency magnetohydrodynamic turbulence in these regions may differ from that in super-Alfvenic wind. We apply a new mode-decomposition…

The recently suggested swing interaction between fast magnetosonic and Alfven waves (Zaqarashvili and Roberts 2002) is generalized to inhomogeneous media. We show that the fast magnetosonic waves propagating across an applied non-uniform…

Astrophysics · Physics 2014-10-13 B. M. Shergelashvili , T. V. Zaqarashvili , S. Poedts , B. Roberts

We successfully utilise the SPARC code to model fast-Alfv\'en mode conversion in the region $c_A \gg c_S$ via 3-D MHD numerical simulations of helioseismic waves within constant inclined magnetic field configurations. This was achieved only…

Solar and Stellar Astrophysics · Physics 2015-06-15 H Moradi , P S Cally