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The Mars Global Surveyor (MGS), Mars Express (MEX), and Venus Express (VEX) experienced several superior solar conjunctions. These conjunctions cause severe degradations of radio signals when the line of sight between the Earth and the…

Space Physics · Physics 2013-01-08 A. K. Verma , A. Fienga , J. Laskar , K. Issautier , H. Manche , M. Gastineau

We have developed new methods to calculate dispersion curves (analytically in the simpler cases) from which we are able to derive the spatial distribution of electron and current densities. We investigate the case where the magnetic field…

Condensed Matter · Physics 2009-10-28 E. Hofstetter , J. M. C. Taylor , A. MacKinnon

We investigate the relationship between solar coronal holes and open-field regions using three-dimensional radiative magnetohydrodynamic (MHD) simulations combined with remote-sensing observations from the Solar Dynamics Observatory (SDO).…

Solar and Stellar Astrophysics · Physics 2025-10-31 Haruhisa Iijima

We present a new method to reconstruct the three-dimensional electron density of coronal mass ejections (CMEs) based on a genetic algorithm, namely the genetic reconstruction method (GRM). GRM is first applied to model CMEs with different…

Solar and Stellar Astrophysics · Physics 2020-07-22 Xinghua Dai , Huaning Wang , Bernd Inhester

In the present work we study evolution of magnetic helicity in the solar corona. We compare the rate of change of a quantity related to the magnetic helicity in the corona to the flux of magnetic helicity through the photosphere and find…

Solar and Stellar Astrophysics · Physics 2021-06-29 A. Malanushenko , M. H. Yusuf , D. W. Longcope

In this paper we provide formulae that can be used to determine the uncertainty contributed to a measurement by a $K$-correction and, thus, valuable information about which flux measurement will provide the most accurate $K$-corrected…

Astrophysics of Galaxies · Physics 2016-10-13 Sean E. Lake , E. L. Wright

I characterize the global distribution of the 3/4 keV band background with a simple model of the hot Galactic corona, plus an isotropic extragalactic background. The corona is assumed to be approximately polytropic (index = 5/3) and…

Astrophysics · Physics 2009-10-30 Q. Daniel Wang

We study the propagation of electromagnetic (EM) waves in the solar system and develop a Mie theory that accounts for the refractive properties of the free electron plasma in the extended solar corona. We use a generic model for the…

Optics · Physics 2019-02-25 Slava G. Turyshev , Viktor T. Toth

An accurate expression of the kinetic energy density of an electronic distribution in terms of the single particle reduced density matrix for atomic and molecular systems is a long-standing problem in electron structure theory. Existing…

Chemical Physics · Physics 2024-10-30 Priya , Mainak Sadhukhan

We present detailed calculations of the electron thermalization by synchrotron self-absorption accounting for cooling by Compton scattering. For the first time, we solve coupled kinetic equations for electrons and photons without any…

Astrophysics · Physics 2009-06-23 Indrek Vurm , Juri Poutanen

X-ray and EUV observations are an important diagnostic of various plasma parameters of the solar atmosphere during solar flares. Soft X-ray and EUV observations often show coronal sources near the top of flaring loops, while hard X-ray…

Solar and Stellar Astrophysics · Physics 2015-06-11 Marina Battaglia , Eduard P. Kontar

We carry out a study of the global three-dimensional (3D) structure of the electron density and temperature of the quiescent inner solar corona ($r<1.25 R_\odot$) by means of tomographic reconstructions and magnetohydrodynamic simulations.…

Solar and Stellar Astrophysics · Physics 2020-06-17 D. G. Lloveras , A. M. Vásquez , F. A. Nuevo , C. Mac Cormack , N. Sachdeva , W. Manchester , B. Van der Holst , R. A. Frazin

The recently published analytic probability density function for the mildly non-linear cosmic density field within spherical cells is used to build a simple but accurate maximum likelihood estimate for the redshift evolution of the variance…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-25 S. Codis , C. Pichon , F. Bernardeau , C. Uhlemann , S. Prunet

For the first time, we have used RHESSI's spatial and energy resolution to determine the combined chromospheric and coronal density profile of the flaring solar atmosphere in a statistical manner, using a dataset of 838 flares observable in…

Solar and Stellar Astrophysics · Physics 2015-06-03 Pascal Saint-Hilaire , Sam Krucker , Robert P. Lin

Understanding how the solar corona is structured is of fundamental importance to determining how the Sun's upper atmosphere is heated to high temperatures. Recent spectroscopic studies have suggested that an instrument with a spatial…

Solar and Stellar Astrophysics · Physics 2013-07-18 David H. Brooks , Harry P. Warren , Ignacio Ugarte-Urra , Amy R. Winebarger

Observations of radio noise storms can act as sensitive probes of nonthermal electrons produced in small acceleration events in the solar corona. We use data from noise storm episodes observed jointly by the Giant Metrewave Radio Telescope…

Solar and Stellar Astrophysics · Physics 2018-05-22 Tomin James , Prasad Subramanian

Kernel density estimation is a technique for approximating probability distributions. Here, it is applied to the calculation of mutual information on a metric space. This is motivated by the problem in neuroscience of calculating the mutual…

Information Theory · Computer Science 2014-05-20 R. Joshua Tobin , Conor J. Houghton

ALMA observations of the Sun at mm-$\lambda$ offer a unique opportunity to investigate the temperature structure of the solar chromosphere. In this article we expand our previous work on modeling the chromospheric temperature of the quiet…

Solar and Stellar Astrophysics · Physics 2020-08-19 C. E. Alissandrakis , A. Nindos , T. S. Bastian , S. Patsourakos

Using Hinode EUV Imaging Spectrometer (EIS) spectra recorded daily at Sun center from the end of 2006 to early 2011, we studied the long-term evolution of the quiet corona. The light curves of the higher temperature emission lines exhibit…

Solar and Stellar Astrophysics · Physics 2012-07-17 S. Kamio , J. T. Mariska

Most treatments of electron-electron correlations in dense plasmas either ignore them entirely (random phase approximation) or neglect the role of ions (jellium approximation). In this work, we go beyond both these approximations to derive…

Plasma Physics · Physics 2020-02-05 Nathaniel R. Shaffer , Charles E. Starrett