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Related papers: Spicule-like structures observed in 3D realistic M…

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A dominant constituent in the dynamic chromosphere are spicules. Spicules at the limb appear as relatively small and dynamic jets that are observed to everywhere stick out. Many papers emphasize the important role spicules might play in the…

Solar and Stellar Astrophysics · Physics 2015-06-23 H. Skogsrud , L. Rouppe van der Voort , B. De Pontieu

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

Lateral motions of spicules serve as vital indicators of transverse waves in the solar atmosphere, and their study is crucial for understanding the wave heating process of the corona. Recent observations have focused on "high-frequency"…

Solar and Stellar Astrophysics · Physics 2023-11-29 Hidetaka Kuniyoshi , Munehito Shoda , Richard J. Morton , Takaaki Yokoyama

We amassed statistics for quiet-sun chromosphere spicules at the limb using ground-based observations from the Swedish 1-m Solar Telescope on La Palma and simultaneously from NASA's Transition Region and Coronal Explorer (TRACE) spacecraft.…

Solar and Stellar Astrophysics · Physics 2010-11-01 Jay M. Pasachoff , William A. Jacobson , Alphonse C. Sterling

Advanced 3D radiative MHD simulations now reproduce many properties of the outer solar atmosphere. When including a domain from the convection zone into the corona, a hot chromosphere and corona are self-consistently maintained. Here we…

Solar and Stellar Astrophysics · Physics 2015-10-07 Viggo Hansteen , Nuno Guerreiro , Bart De Pontieu , Mats Carlsson

Context. The surface structures and dynamics of cool stars are characterized by the presence of convective motions and turbulent flows which shape the emergent spectrum. Aims. We used realistic three-dimensional radiative hydrodynamical…

Solar and Stellar Astrophysics · Physics 2018-03-14 A. Chiavassa , L. Casagrande , R. Collet , Z. Magic , L. Bigot , F. Thevenin , M. Asplund

In this work, we study and quantify properties of strong-field small-scale convection and compare observed properties with those predicted by numerical simulations. We analyze spectropolarimetric 630.25 nm data from a unipolar ephemeral…

Solar and Stellar Astrophysics · Physics 2015-05-19 G. Narayan , G. B. Scharmer

Isotropic homogeneous hydromagnetic turbulence is studied using numerical simulations at resolutions of up to 1024^3 meshpoints. It is argued that, in contrast to the kinematic regime, the nonlinear regime is characterized by a spectral…

Astrophysics · Physics 2007-05-23 A. Brandenburg , N. E. L. Haugen , W. Dobler

We examine the effect of uniform ambient magnetic fields on the evolution of supernova-driven blast waves into a homogeneous ambient ISM in thermal equilibrium. Using the Pencil Code we simulate high resolution nonideal magnetohydrodynamic…

High Energy Astrophysical Phenomena · Physics 2019-09-24 Cetin Can Evirgen , Frederick Gent

We study the properties of solar magnetic fields on scales less than the spatial resolution of solar telescopes. A synthetic infrared spectropolarimetric diagnostics based on a 2D MHD simulation of magnetoconvection is used for this. We…

Solar and Stellar Astrophysics · Physics 2009-02-10 V. A. Sheminova

The Magneto-hydrodynamic (MHD) equations in the presence of a guiding magnetic field are investigated by means of direct numerical simulations. The basis of the investigation consists of 9 runs forced at the small scales. The results…

Fluid Dynamics · Physics 2015-05-30 Alexandros Alexakis

Solar spicules are the fundamental magnetic structures in the chromosphere and considered to play a key role in channelling the chromosphere and corona. Recently, it was suggested by De Pontieu et al. that there were two types of spicules…

Solar and Stellar Astrophysics · Physics 2012-04-17 Y. Z. Zhang , K. Shibata , J. X. Wang , X. J. Mao , T. Matsumoto , Y. Liu , J. T. Su

Radiative hydrodynamic simulations of solar and stellar surface convection have become an important tool for exploring the structure and gas dynamics in the envelopes and atmospheres of late-type stars and for improving our understanding of…

Solar and Stellar Astrophysics · Physics 2015-06-03 B. Beeck , R. Collet , M. Steffen , M. Asplund , R. H. Cameron , B. Freytag , W. Hayek , H. -G. Ludwig , M. Schüssler

The role of type II spicules in the corona has been a much debated topic in recent years. This paper aims to shed light on the impact of type II spicules in the corona using novel 2.5D radiative MHD simulations including ion-neutral…

Solar and Stellar Astrophysics · Physics 2018-07-04 Juan Martínez-Sykora , Bart De Pontieu , Ineke De Moortel , Viggo H. Hansteen , Mats Carlsson

Using a new, second-order accurate numerical method we present dynamical simulations of oblique MHD cosmic ray (CR) modified plane shock evolution using the two-fluid model for diffusive particle acceleration. The numerical shocks evolve to…

Astrophysics · Physics 2009-10-22 Adam Frank , T. W. Jones , Dongsu Ryu

We study a granular-sized magnetic flux emergence event that occurred in NOAA 11024 in July 2009. The observations were made with the CRISP spectropolarimeter at the Swedish 1 m Solar Telescope achieving a spatial resolution of 0.14".…

Solar and Stellar Astrophysics · Physics 2015-06-18 Ada Ortiz , Luis Bellot Rubio , Viggo Hansteen , Jaime de la Cruz Rodriguez , Luc Rouppe van der Voort

We investigate properties of plasma turbulence from magneto-hydrodynamic (MHD) to sub-ion scales by means of two-dimensional, high-resolution hybrid particle-in-cell simulations. We impose an initial ambient magnetic field, perpendicular to…

Solar and Stellar Astrophysics · Physics 2015-10-14 Luca Franci , Simone Landi , Lorenzo Matteini , Andrea Verdini , Petr Hellinger

The structure and dynamics of small vertical photospheric magnetic flux concentrations has been often treated in the framework of an approximation based upon a low-order truncation of the Taylor expansions of all quantities in the…

Solar and Stellar Astrophysics · Physics 2010-11-02 L. Yelles Chaouche , S. K. Solanki , M. Schuessler

Solar spicules are chromospheric fibrils that appear everywhere on the Sun, yet their origin is not understood. Using high resolution observations of spicules obtained with the Swedish 1-m Solar Telescope, we aim to understand how spicules…

Solar and Stellar Astrophysics · Physics 2016-06-22 Tiago M. D. Pereira , Luc Rouppe van der Voort , Mats Carlsson

We infer the 3D magnetic structure of a transient horizontal magnetic field (THMF) during its evolution through the photosphere using SIRGAUS inversion code. The SIRGAUS code is a modified version of SIR (Stokes Inversion based on Response…

Solar and Stellar Astrophysics · Physics 2015-05-18 R. Ishikawa , S. Tsuneta , J. Jurcak