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Related papers: Chromospheric Extension of the MURaM Code

200 papers

Context. High energy electrons accelerated during solar flare are abundant in the solar corona and in the interplanetary space. Commonly, the number and the energy of non-thermal electrons at the Sun is estimated using hard X-ray (HXR)…

Solar and Stellar Astrophysics · Physics 2015-06-03 E. P. Kontar , H. Ratcliffe , N. H. Bian

We investigate the thermal response of the atmosphere of a solar-type star to an electron beam injected from a hot Jupiter by performing a 1-dimensional magnetohydrodynamic numerical experiment with non-linear wave dissipation, radiative…

Solar and Stellar Astrophysics · Physics 2014-11-20 Pin-Gao Gu , Takeru K. Suzuki

It remains unclear which physical processes are responsible for the dramatic increase with height of the temperature in stellar atmospheres, known as the chromospheric ($\sim$10,000 K) and coronal (several million K) heating problems.…

Solar and Stellar Astrophysics · Physics 2022-11-17 Souvik Bose , Bart De Pontieu , Viggo Hansteen , Alberto Sainz Dalda , Sabrina Savage , Amy Winebarger

The optical and near-ultraviolet (NUV) continuum radiation in M dwarf flares is thought to be the impulsive response of the lower stellar atmosphere to magnetic energy release and electron acceleration at coronal altitudes. This radiation…

Solar and Stellar Astrophysics · Physics 2023-02-07 Adam F. Kowalski

The periodic coronal rain and in-phase radiative intensity pulsations have been observed in multiple wavelengths in recent years. However, due to the lack of three-dimensional coronal magnetic fields and thermodynamic data in observations,…

Solar and Stellar Astrophysics · Physics 2024-09-02 Zekun Lu , Feng Chen , J. H. Guo , M. D. Ding , Can Wang , Haocheng Yu , Y. W. Ni , Chun Xia

In this paper, we show a "proof of concept" of the heating mechanism of the solar chromosphere due to wave dissipation caused by the effects of partial ionization. Numerical modeling of non-linear wave propagation in a magnetic flux tube,…

Solar and Stellar Astrophysics · Physics 2016-03-16 S. Shelyag , E. Khomenko , A. de Vicente , D. Przybylski

In this paper we have extended our previous modeling of energy balance in the chromosphere-corona transition region to cases with particle and mass flows. The cases considered here are quasi-steady, and satisfy the momentum and energy…

Astrophysics · Physics 2009-11-07 J. M. Fontenla , E. H. Avrett , R. Loeser

Using high-resolution numerical simulations we investigate the plasma heating driven by periodic two-fluid acoustic waves that originate at the bottom of the photosphere and propagate into the gravitationally stratified and partially…

Solar and Stellar Astrophysics · Physics 2019-06-26 B. Kuźma , D. Wójcik , K. Murawski

We present an efficient heating/cooling method coupled with chemistry and ultraviolet (UV) radiative transfer, which can be applied to numerical simulations of the interstellar medium (ISM). We follow the time-dependent evolution of…

Astrophysics of Galaxies · Physics 2022-12-28 Jeong-Gyu Kim , Munan Gong , Chang-Goo Kim , Eve C. Ostriker

Modeling the variability of the solar spectral irradiance is a key factor for understanding the solar influence on the climate of the Earth. As a first step to calculating the solar spectral irradiance variations we reproduce the solar…

Astrophysics · Physics 2009-11-13 M. Haberreiter , W. Schmutz , I. Hubeny

The TIRAMISU code, a new program for computing on-the-fly non-LTE molecular spectra and opacities for solving self-consistent radiative transfer problems in exoplanet atmospheres, is presented. The ultra-hot Jupiter KELT-20 b is used as a…

Earth and Planetary Astrophysics · Physics 2025-08-19 Charles A. Bowesman , Sergei N. Yurchenko , Ahmed Al-Refaie , Jonathan Tennyson

We investigate the synthesis of the Balmer and Paschen lines of the quiet Sun, using both classical semi-empirical and theoretical model atmospheres, modern line broadening theory and non-LTE line-formation. The computations alleviate…

Astrophysics · Physics 2009-11-10 Norbert Przybilla , Keith Butler

We present a method of conducting data-driven simulations of solar active regions and flux emergence with the MURaM radiative magnetohydrodynamics (MHD) code. The horizontal electric field derived from the full velocity and magnetic…

Solar and Stellar Astrophysics · Physics 2023-06-14 Feng Chen , Mark C. M. Cheung , Matthias Rempel , Georgios Chintzoglou

An accurate estimate of the energy budget (heating and cooling) of the ionosphere and thermosphere, especially during space weather events, has been a challenge. The abundance of Nitric Oxide (NO), a minor species in the thermosphere, is an…

Space Physics · Physics 2019-01-23 Cissi Y. Lin , Yue Deng , Karthik Venkataramani , Justin Yonker , Scott M. Bailey

Our aim is to determine the dominant processes and timescales for the ionisation equilibrium of calcium under solar chromospheric conditions. The study is based on numerical simulations with the RADYN code, which includes hydrodynamics,…

Solar and Stellar Astrophysics · Physics 2015-05-27 Sven Wedemeyer-Böhm , Mats Carlsson

Aims: To investigate magnetic reconnection rates during the coalescence of two current loops in the solar chromosphere, by altering the neutral-hydrogen to proton density ratio, ioniziation/recombination coefficients, collision frequency…

Astrophysics · Physics 2009-11-13 P. D. Smith , J. I. Sakai

Magnetohydrodynamic (MHD) plasma turbulence is believed to play a vital role in the production of energetic electrons during solar flares and the non-thermal broadening of spectral lines is a key sign of this turbulence. Here, we determine…

Solar and Stellar Astrophysics · Physics 2021-12-22 Morgan Stores , Natasha L. S. Jeffrey , Eduard P. Kontar

We investigate the effect of coronal temperature on the formation process of solar chromospheric jets using two-dimensional magnetohydrodynamic simulations of the region from the upper convection zone to the lower corona. We develop a new…

Solar and Stellar Astrophysics · Physics 2015-10-28 H. Iijima , T. Yokoyama

The broadening of the hydrogen lines during flares is thought to result from increased charge (electron, proton) density in the flare chromosphere. However, disagreements between theory and modeling prescriptions have precluded an accurate…

Most static 1D atmosphere models in the quiet Sun predict a rise of the gas temperature at chromospheric layers, but numerical simulations only yield an increase in the brightness temperature. We investigate the thermal structure in the…

Solar and Stellar Astrophysics · Physics 2013-05-08 C. Beck , R. Rezaei , K. G. Puschmann