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The presence of the magnetic field is critical to transport energy through the solar atmosphere. The new generation of telescopes will provide new insight into how the magnetic field arrives into the chromosphere and its role in the energy…

Solar and Stellar Astrophysics · Physics 2022-11-17 Juan Martínez-Sykora , Alberto Sainz Dalda , Milan Gošić , Bart De Pontieu

Recently, it has been proposed that the magnetic-field-induced transition (MIT) in Fe X can be used to measure coronal magnetic field strengths. Several techniques, the direct line ratio technique and the weak and strong magnetic field…

Solar and Stellar Astrophysics · Physics 2023-03-08 Yajie Chen , Xianyong Bai , Hui Tian , Wenxian Li , Feng Chen , Zihao Yang , Yang Yang

There is a pressing need to model X-ray Ultra-Violet (XUV: 1-30 nm) stellar irradiances, given the scarcity of current measurements. One of the measurable effects of a stellar cycle is the significant (more than one order of magnitude)…

Solar and Stellar Astrophysics · Physics 2025-04-14 E. Deliporanidou , G. Del Zanna , T. N. Woods , D. Woodraska

Gamma-ray spectroscopy provides diagnostics of particle acceleration in solar flares, but care must be taken when interpreting the spectra due to effects of the angular distribution of the accelerated particles (such as relativistic…

Solar and Stellar Astrophysics · Physics 2015-05-20 Shichao Tang , David M. Smith

The application of molecular dynamics (MD) simulations to the interpretation of Raman scattering spectra is hindered by inability of atomistic simulations to account for the dynamic evolution of electronic polarizability, requiring the use…

Materials Science · Physics 2023-04-18 Atanu Paul , Anthony Ruffino , Stefan Masiuk , Jonathan Spanier , Ilya Grinberg

We use the COMPLETE Survey's observations of the Perseus star-forming region to assess and intercompare three methods for measuring column density in molecular clouds: extinction mapping (NIR); thermal emission mapping (FIR); and mapping…

Astrophysics · Physics 2011-02-11 Alyssa A. Goodman , Jaime E. Pineda , Scott L. Schnee

Proton radiography is a widely-fielded diagnostic used to measure magnetic structures in plasma. The deflection of protons with multi-MeV kinetic energy by the magnetic fields is used to infer their path-integrated field strength. Here, the…

An application of active contours without edges is presented as an efficient and effective means of extracting and characterizing coronal holes. Coronal holes are regions of low-density plasma on the Sun with open magnetic field lines. As…

Solar and Stellar Astrophysics · Physics 2016-10-05 L. E. Boucheron , M. Valluri , R. T. J. McAteer

A detailed study of emission lines from Fe VII, Fe VIII and Fe IX observed by the EUV Imaging Spectrometer on board the Hinode satellite is presented. Spectra in the ranges 170-212 A and 246-292 A show strongly enhanced lines from the upper…

Solar and Stellar Astrophysics · Physics 2015-05-13 P. R. Young , E. Landi

The X-ray and EUV emission of stars plays a key role in the loss and evolution of the atmospheres of their planets. The coronae of dwarf stars later than M6 appear to behave differently to those of earlier spectral types and are more X-ray…

Solar and Stellar Astrophysics · Physics 2020-05-06 Jeremy J. Drake , Vinay L. Kashyap , Bradford J. Wargelin , Scott J. Wolk

Fully relativistic calculations of radiative rates and electron impact excitation cross sections for Fe X are used to derive theoretical emission-line ratios involving transitions in the 174-366 A wavelength range. A comparison of these…

Astrophysics · Physics 2009-11-13 F P Keenan , D B Jess , K M Aggarwal , R J Thomas , J W Brosius , J M Davila

On 2008 January 10, the twin Solar Terrestrial Relations Observatory (STEREO) A and B spacecraft conducted a high time cadence study of the solar corona with the Extreme UltraViolet Imager (EUVI) instruments with the aim of investigating…

Solar and Stellar Astrophysics · Physics 2010-01-15 M. S. Marsh , R. W. Walsh , S. Plunkett

A major challenge in solar physics is to obtain empirical information on the magnetic field of the million-degree plasma of the solar corona. To this end, we need observables of the solar radiation sensitive to the coronal magnetic field.…

Measuring the relative amount of high-temperature, low-emission-measure plasma is considered to be a smoking gun observation to constrain the frequency of plasma heating in coronal structures. Often, narrowband, extreme ultraviolet images,…

Solar and Stellar Astrophysics · Physics 2024-01-24 P. S. Athiray , Amy R. Winebarger

Measuring the temperature structure of the solar atmosphere is critical to understanding how it is heated to high temperatures. Unfortunately, the temperature of the upper atmosphere cannot be observed directly, but must be inferred from…

Solar and Stellar Astrophysics · Physics 2017-03-08 Harry P. Warren , Jeff M. Byers , Nicholas A. Crump

The advent of the X-ray microcalorimeter spectrometer Resolve onboard the XRISM space telescope opened a new era for high-resolution X-ray spectroscopy of astrophysical plasmas. Many spectral features were newly detected, including the K…

We describe a new algorithm for reconstruction of Differential Emission Measures (DEMs) in the solar corona. Although a number of such algorithms currently exist, they can have difficulty converging for some cases, and can be complex, slow,…

Solar and Stellar Astrophysics · Physics 2020-12-11 Joseph Plowman , Amir Caspi

The charged environment within a dense plasma leads to the phenomenon of ionization potential depression (IPD) for ions embedded in the plasma. Accurate predictions of the IPD effect are of crucial importance for modeling atomic processes…

Plasma Physics · Physics 2014-07-10 Sang-Kil Son , Robert Thiele , Zoltan Jurek , Beata Ziaja , Robin Santra

The goal of this paper is to apply statistical methods to determine electrons densities and their errors from measurements of density-sensitive line intensities in the quiet Sun. Three methods are employed. The first is the use of…

Solar and Stellar Astrophysics · Physics 2020-06-17 Kenneth Dere
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