English
Related papers

Related papers: Coronal Alfven speeds in an isothermal atmosphere …

200 papers

The solar corona is a hot, dynamic, and highly magnetized plasma environment whose source of energy is not yet well understood. One leading contender for that energy source is the dissipation of magnetohydrodynamic (MHD) waves or turbulent…

Solar and Stellar Astrophysics · Physics 2018-08-01 Steven R. Cranmer

We use local stratified shearing-box simulations to elucidate the impact of two-temperature thermodynamics on the thermal structure of coronae in radiatively efficient accretion flows. Rather than treating the coronal plasma as an…

High Energy Astrophysical Phenomena · Physics 2023-11-01 Christopher J. Bambic , Eliot Quataert , Matthew W. Kunz

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 origin of the heliospheric magnetic flux on the Sun, and hence the origin of the solar wind, is a topic of hot debate.While the prevailing view is that the solar wind originates from outside coronal streamer helmets, there also exists…

Solar and Stellar Astrophysics · Physics 2015-06-05 Bo Li , Xing Li , Hui Yu

Determining the mechanisms responsible for the heating of the coronal plasma and maintaining and accelerating the solar wind are long standing goals in solar physics. There is a clear need to constrain the energy, mass and momentum flux…

Solar and Stellar Astrophysics · Physics 2016-11-21 R. J. Morton , E. Scullion , D. S. Bloomfield , J. A. McLaughlin , S. Regnier , S. W. McIntosh , S. Tomczyk , P. Young

Waves are thought to play a significant role in the heating of the solar atmosphere and the acceleration of the wind. Among the many types of waves observed in the Sun, the so-called p-modes with a 3 mHz frequency peak dominate the lower…

Differential flows among different ion species are often observed in the solar wind, and such ion differential flows can provide the free energy to drive Alfv\'en/ion-cyclotron and fast-magnetosonic/whistler instabilities. Previous works…

Solar and Stellar Astrophysics · Physics 2021-11-01 Wen Liu , Jinsong Zhao , Huasheng Xie , Yuhang Yao , Dejin Wu , L. C. Lee

Alfv\'en waves may be generated via mode conversion from fast magneto-acoustic waves near their reflection level in the solar atmosphere, with implications both for coronal oscillations and for active region helio-seismology. In active…

Solar and Stellar Astrophysics · Physics 2015-05-28 Paul S. Cally , Shelley C. Hansen

M dwarf's atmosphere and wind is expected to be highly magnetized. The nonlinear propagation of Alfv\'en wave could play a key role in both heating the stellar atmosphere and driving the stellar wind. Along this Alfv\'en wave scenario, we…

Solar and Stellar Astrophysics · Physics 2021-01-20 Takahito Sakaue , Kazunari Shibata

We establish a spherically symmetric model of solar atmosphere, which consists of the whole chromosphere and low corona below the $1.25$ solar radius. It is a hydrodynamic model with heating in the chromosphere through an artificial energy…

Solar and Stellar Astrophysics · Physics 2025-03-13 Li Xue , Cheng-Liang Jiao , Li-Xin Zhang

We report the detection of oscillatory phenomena associated with a large bright-point group that is 430,000 square kilometers in area and located near the solar disk center. Wavelet analysis reveals full-width half-maximum oscillations with…

Solar and Stellar Astrophysics · Physics 2009-11-13 D. B. Jess , M. Mathioudakis , R. Erdelyi , P. J. Crockett , F. P. Keenan , D. J. Christian

Close to Earth the solar wind is usually super-Alfv\'enic, i.e. the speed of the solar wind is much larger than the Alfv\'en speed. However, in the lower coronal regions, the solar wind is mostly sub-Alfv\'enic. With the Parker Solar Probe…

Poynting flux generated by random shuffling of photospheric magnetic footpoints is transferred through the upper atmosphere of the Sun where the plasma is heated to over 1 MK in the corona. High spatiotemporal resolution observations of the…

Solar and Stellar Astrophysics · Physics 2024-11-20 L. P. Chitta , M. van Noort , H. N. Smitha , E. R. Priest , L. H. M. Rouppe van der Voort

The discovery of ubiquitous low-frequency (3-5mHz) Alfvenic waves in the solar chromosphere (with Hinode/SOT), and corona (with CoMP and the Solar Dynamics Observatory, SDO) has provided some insight into the non-thermal energy content of…

Solar and Stellar Astrophysics · Physics 2015-06-12 Scott W. McIntosh , Bart De Pontieu

The equilibrium of current-carrying magnetic fields (e.g. flux tubes) embedded in a large-scale background field is developed and discussed in the astrophysical context. Embedded non-force-free current-carrying fields require a minimum…

Solar and Stellar Astrophysics · Physics 2019-03-26 Laurence J. November

Radio signals propagating via the solar corona and solar wind are significantly affected by compressive waves, impacting properties of solar bursts as well as sources viewed through the turbulent solar atmosphere. While static fluctuations…

Solar and Stellar Astrophysics · Physics 2024-04-23 Francesco Azzollini , A. Gordon Emslie , Daniel L. Clarkson , Nicolina Chrysaphi , Eduard P. Kontar

Coronal seismology is a diagnostic tool used in solar physics for measuring parameters that are otherwise hard to measure; of these parameters, magnetic field values are arguably the most important. The parameters are inferred by combining…

Solar and Stellar Astrophysics · Physics 2018-04-17 N. Magyar , T. Van Doorsselaere

A magnetohydrodynamic model is used to determine conditions under which the Lorentz force accelerates plasma to type 2 spicule speeds in the chromosphere. The model generalizes a previous model to include a more realistic pre-spicule state,…

Solar and Stellar Astrophysics · Physics 2015-06-19 Michael L. Goodman

In this paper, results of 2.5-dimensional magnetohydrodynamical simulations are reported for the magnetic reconnection of non-perfectly antiparallel magnetic fields. The magnetic field has a component perpendicular to the computational…

Solar and Stellar Astrophysics · Physics 2015-05-18 Hiromitsu Kigure , Kunio Takahashi , Kazunari Shibata , Takaaki Yokoyama , Satoshi Nozawa

The heating of the solar corona and solar wind, through suprathermal particles and kinetic Alfv\'en waves within the 0 - 10 $R_{\rm Sun}$ range, has been a subject of great interest for many decades. This study investigates the acceleration…

Solar and Stellar Astrophysics · Physics 2025-02-05 S. Ayaz , Gary P. Zank , Imran A. Khan , G. Li , Yeimy J. Rivera
‹ Prev 1 4 5 6 7 8 10 Next ›