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Observations show that propagating magnetohydrodynamic (MHD) waves are ubiquitous in the solar atmosphere. The technique of MHD seismology uses the wave observations combined with MHD wave theory to indirectly infer physical parameters of…

Solar and Stellar Astrophysics · Physics 2015-06-11 M. Goossens , R. Soler , I. Arregui , J. Terradas

The paper considers the dynamics of the plasma generated by the explosive-emission cells of the cathode spot of a vacuum arc in a magnetic field. It is shown that the expansion of the (high-density) plasma in a transverse magnetic field may…

Plasma Physics · Physics 2019-05-22 M. M. Tsventoukh

Current sheets (CSs), long stretching structures of magnetic reconnection above solar flare loops, are usually observed to oscillate, their origins, however, are still puzzled at present. Based on a high-resolution 2.5-dimensional MHD…

Solar and Stellar Astrophysics · Physics 2023-09-11 Yulei Wang , Xin Cheng , Zining Ren , Mingde Ding

We use seven high-resolution $N$-body simulations to study the correlations among different halo properties (assembly time, spin, shape and substructure), and how these halo properties are correlated with the large-scale environment in…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Huiyuan Wang , H. J. Mo , Y. P. Jing , Xiaohu Yang , Yu Wang

Measurements of intensity and polarization of diffuse Galactic synchrotron emission as well as starlight polarization reveal power law spectra of fluctuations. We show that these fluctuations can arise from magnetohydrodynamic (MHD)…

Astrophysics · Physics 2016-08-30 Jungyeon Cho , A. Lazarian

A three-dimensional MHD model for the propagation and dissipation of Alfven waves in a coronal loop is developed. The model includes the lower atmospheres at the two ends of the loop. The waves originate on small spatial scales (less than…

Solar and Stellar Astrophysics · Physics 2015-05-28 A. A. van Ballegooijen , M. Asgari-Targhi , S. R. Cranmer , E. E. DeLuca

In the tidal-torque theory, the angular momentum (AM) of dark matter halos arises from the tidal torque suffered by aspherical collapsing patches due to surrounding mass fluctuations. This theory was implemented in the peak model where…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-01 Eduard Salvador-Solé , Alberto Manrique

We study the synchrotron radio emission from extra-planar regions of star forming galaxies. We use ideal magneto-hydrodynamical (MHD) simulations of a rotating Milky Way-type disk galaxy with distributed star formation sites for three star…

Astrophysics of Galaxies · Physics 2020-01-08 Aditi Vijayan , Biman B. Nath , Prateek Sharma , Yuri Shchekinov

While it is possible to estimate the dark matter density at the Sun distance from the galactic center, this does not give information on actual dark matter density in the Solar system. There can be considerable local enhancement of dark…

High Energy Physics - Phenomenology · Physics 2024-08-21 Dmitry Budker , Joshua Eby , Marianna S. Safronova , Oleg Tretiak

Waves and oscillations are important solar phenomena, not only because they can propagate and dissipate energy in the chromosphere, but also because they carry information about the structure of the atmosphere in which they propagate. The…

Solar and Stellar Astrophysics · Physics 2022-01-26 Yi Chai , Dale E. Gary , Kevin P. Reardon , Vasyl Yurchyshyn

We perform three dimensional (3D) ideal magnetohydrodynamic (MHD) simulations to study the parametric decay instability of Alfven waves in turbulent plasmas and explore its possible applications in the solar wind. We find that, over a broad…

Space Physics · Physics 2017-06-16 Mijie Shi , Hui Li , Chijie Xiao , Xiaogang Wang

It is widely accepted that solar active regions including sunspots are formed by the emerging magnetic flux from the deep convection zone. In previous numerical simulations, we found that the horizontal divergent flow (HDF) occurs before…

Solar and Stellar Astrophysics · Physics 2015-06-04 S. Toriumi , K. Hayashi , T. Yokoyama

We present a first attempt to investigate the origin of radio-emitting electrons in the newly discovered class of mega radio halos in clusters of galaxies. We study the evolution of relativistic electrons accreted by the external regions of…

High Energy Astrophysical Phenomena · Physics 2023-10-02 L. Beduzzi , F. Vazza , G. Brunetti , V. Cuciti , D. Wittor , E. M. Corsini

A model is presented for generation of fast solar wind in coronal holes, relying on heating that is dominated by turbulent dissipation of MHD fluctuations transported upwards in the solar atmosphere. Scale-separated transport equations…

Solar and Stellar Astrophysics · Physics 2015-05-14 A. Verdini , M. Velli , W. H. Matthaeus , S. Oughton , P. Dmitruk

It was suggested that the $\gamma$-ray halo around Geminga might not be interpreted by slow-diffusion. If the ballistic regime of electron/positron propagation is considered, the Geminga halo may be explained even with a large diffusion…

High Energy Astrophysical Phenomena · Physics 2022-09-21 Li-Zhuo Bao , Kun Fang , Xiao-Jun Bi , Sheng-Hao Wang

In the present review article, we discuss the recent developments in studying the Kelvin--Helmholtz (KH) instability of magnetohydrodynamic (MHD) waves propagating in various solar magnetic structures. The main description is on the…

Solar and Stellar Astrophysics · Physics 2015-05-20 I. Zhelyazkov

The source of the non-thermal energy required for the heating of the upper solar atmosphere to temperatures in excess of a million degrees and the acceleration of the solar wind to hundreds of kilometres per second is still unclear. One…

Solar and Stellar Astrophysics · Physics 2015-06-17 R. J. Morton , G. Verth , A. Hillier , R. Erdélyi

Particles ejected from the Sun that stream through the surrounding plasma of the solar wind are causing instabilities. These generate wavemodes in a certain frequency range especially within shock regions, where particles are accelerated.…

Solar and Stellar Astrophysics · Physics 2015-06-11 Sebastian Lange , Felix Spanier

The primordial matter power spectrum quantifies fluctuations in the distribution of dark matter immediately following inflation. Over cosmic time, over-dense regions of the primordial density field grow and collapse into dark matter halos,…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-30 Daniel Gilman , Andrew Benson , Jo Bovy , Simon Birrer , Tommaso Treu , Anna Nierenberg

Dissipation of magnetohydrodynamic (MHD) wave energy has been proposed as a viable heating mechanism in the solar chromospheric plasma. Here, we use a simplified one-dimensional model of the chromosphere to theoretically investigate the…

Solar and Stellar Astrophysics · Physics 2015-09-23 Roberto Soler , Marc Carbonell , Jose Luis Ballester
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