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Related papers: Solar off-limb line widths: Alfven waves, ion-cycl…

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We have developed a numerical model of flare heating due to the dissipation of Alfv\'enic waves propagating from the corona to the chromosphere. With this model, we present an investigation of the key parameters of these waves on the energy…

Solar and Stellar Astrophysics · Physics 2016-02-17 Jeffrey W. Reep , Alexander J. B. Russell

We present a unified analysis of the O{\sc vi} absorption-lines seen in the disk and halo of the Milky Way, high velocity clouds, the Magellanic Clouds, starburst galaxies, and the intergalactic medium. We show that these disparate systems…

Astrophysics · Physics 2009-11-07 T. M. Heckman , C. A. Norman , D. K. Strickland , K. R. Sembach

We revisit in more detail a model for element abundance fractionation in the solar chromosphere, that gives rise to the "FIP Effect" in the solar corona and wind. Elements with first ionization potential below about 10 eV, i.e. those that…

Solar and Stellar Astrophysics · Physics 2014-11-18 J. Martin Laming

Magnetic fields are key ingredients for heating the solar corona to temperatures of several million Kelvin. A particularly important region with respect to this is the so-called magnetic canopy below the corona, where sound and Alfv\'en…

Solar and Stellar Astrophysics · Physics 2023-01-23 Th. Gundrum , J. Forbriger , Th. Herrmannsdörfer , G. Mamatsashvili , S. Schnauck , F. Stefani , J. Wosnitza

A semi-empirical, axisymmetric model of the solar minimum corona is developed by solving the equations for conservation of mass and momentum with prescribed anisotropic temperature distributions. In the high-latitude regions, the proton…

Astrophysics · Physics 2009-11-10 Alberto M. Vasquez , Adriaan A. van Ballegooijen , John C. Raymond

Kink oscillations of a coronal loop are observed and studied in detail because they provide a unique probe into the structure of coronal loops through MHD seismology and a potential test of coronal heating through the phase-mixing of…

Solar and Stellar Astrophysics · Physics 2018-08-29 P. Pagano , D. J. Pascoe , I. De Moortel

An isolated, isothermal, and wide magnetic flux tube embedded either in the solar chromosphere or in the lower solar corona is considered, and the propagation of linear torsional Alfv'en waves is investigated. It is shown that the wideness…

Solar and Stellar Astrophysics · Physics 2020-08-25 Swati Routh , Z. E. Musielak , M. N. Sundar , Sai Sravanthi Joshi , Sree Charan

We investigate the effects of heating generated by damping of Alfven waves on protostellar accretion disks. Two mechanisms of damping are investigated, nonlinear and turbulent, which were previously studied in stellar winds (Jatenco-Pereira…

Astrophysics · Physics 2009-10-31 M. J. Vasconcelos , V. Jatenco-Pereira , R. Opher

Phase mixing of Alfven waves is one of the most promising mechanisms for heating of the solar atmosphere. The damping of waves in this case requires small transversal scales, relative to the magnetic field direction. Here this requirement…

Solar and Stellar Astrophysics · Physics 2023-11-07 Max McMurdo , Istvan Ballai , Gary Verth , Abdulaziz Alharbi , Viktor Fedun

Observations have shown that magnetohydrodynamic waves over a large frequency range are ubiquitous in solar prominences. The waves are probably driven by photospheric motions and may transport energy up to prominences suspended in the…

Solar and Stellar Astrophysics · Physics 2016-07-13 Roberto Soler , Jaume Terradas , Ramon Oliver , Jose Luis Ballester

The rapid damping of slow magnetoacoustic waves in the solar corona has been extensively studied in previous years. Most studies suggest that thermal conduction is a dominant contributor to this damping, albeit with a few exceptions.…

Solar and Stellar Astrophysics · Physics 2019-08-02 S. Krishna Prasad , D. B. Jess , T. Van Doorsselaere

New aspects of the slow solar wind turbulent heating and acceleration are investigated. A physical meaning of the lower boundary of the Alfv\'en wave turbulent spectra in the solar atmosphere and the solar wind is studied and the…

Solar and Stellar Astrophysics · Physics 2015-06-04 Bidzina M. Shergelashvili , Horst Fichtner

The O I 1355{\AA} spectral line is one of the only optically thin lines that are both routinely observed and thought to be formed in the chromosphere. We present analysis of a variety of observations of this line with the Interface Region…

Solar and Stellar Astrophysics · Physics 2023-08-29 Mats Carlsson , Bart De Pontieu

We discuss observations of the weak first overtone CO absorption band near 2300 nm with the U.S. National Solar Observatory Array Camera (NAC), a modern mid-infrared detector. This molecular band provides a thermal diagnostic that forms…

Solar and Stellar Astrophysics · Physics 2010-09-01 T. A. Schad , M. J. Penn

This work is an extension of Kaghashvili [1999] where ion-cyclotron wave dissipation channel for Alfv\'en waves was discussed. While our earlier study dealt with the mode coupling in the commonly discussed sense, here we study changes in…

Solar and Stellar Astrophysics · Physics 2014-02-10 Edisher Kh. Kaghashvili

Alfv\'en waves, considered one of the primary candidates for heating and accelerating the fast solar wind, are ubiquitous in spacecraft observations, yet their origin remains elusive. In this study, we analyze data from the first 19…

In this work we analyze plasma and magnetic field data provided by the Parker Solar Probe (\emph{PSP}) and Solar Orbiter (\emph{SO}) missions to investigate the radial evolution of the heating of Alfv\'enic slow wind (ASW) by imbalanced…

When observing spectral lines in the optically-thin corona, line-of-sight (LOS) effects can strongly affect the interpretation of the data, especially in regions just above the limb. We present a semi-empirical forward model, called GHOSTS,…

Solar and Stellar Astrophysics · Physics 2020-10-07 Chris R. Gilly , Steven R. Cranmer

We present an updated global model of the solar corona, including the transition region. We simulate the realistic tree-dimensional (3D) magnetic field using the data from the photospheric magnetic field measurements and assume the…

As the Lyman-alpha (Lya) line of neutral hydrogen is the brightest emission line in the solar spectrum, detecting increases in irradiance due to solar flares at this wavelength can be challenging due to the very high background. Previous…

Solar and Stellar Astrophysics · Physics 2021-03-31 Ryan O. Milligan
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