English
Related papers

Related papers: MHD-shock structures of astrospheres: $\lambda$ Ce…

200 papers

We use 2D numerical simulations and eikonal approximation, to study properties of MHD waves traveling below the solar surface through the magnetic structure of sunspots. We consider a series of magnetostatic models of sunspots of different…

Astrophysics · Physics 2011-02-11 E. Khomenko , A. Kosovichev , M. Collados , K. Parchevsky , V. Olshevsky

We present a direct numerical and analytical study of driven supersonic MHD turbulence that is believed to govern the dynamics of star-forming molecular clouds. We describe statistical properties of the turbulence by measuring the velocity…

Astrophysics · Physics 2009-11-07 Stanislav Boldyrev , Aake Nordlund , Paolo Padoan

We used our newly developed magnetohydrodynamic (MHD) code to perform 2.5D simulations of a fast-mode MHD wave interacting with coronal holes (CH) of varying Alfv\'en speed which result from assuming different CH densities. We find that…

We present two-dimensional, cylindrically symmetric simulations of hydrodynamic and magnetohydrodynamic (MHD) wide-angle winds interacting with a collapsing environment. These simulations have direct relevance to young stellar objects…

Astrophysics · Physics 2009-11-07 T. A. Gardiner , A. Frank , L. Hartmann

We investigate the Mach number dependence of the radiative overstability of shocks. We find that the stability of radiative shocks increases with decreasing Mach number, with the result that M=2 shocks require cooling exponents < -1.2 to be…

Astrophysics · Physics 2009-11-11 J. M. Pittard , M. S. Dobson , R. H. Durisen , J. E. Dyson , T. W. Hartquist , J. T. O'Brien

The astropause (heliopause for the Sun) is the tangential discontinuity separating the stellar wind from the interstellar plasma. The global shape of the heliopause is a matter of debates. Two types of the shape are under discussion:…

Solar and Stellar Astrophysics · Physics 2021-04-28 Sergey Korolkov , Vladislav Izmodenov

Astrophysical fluids are generally turbulent and this preexisting turbulence must be taken into account for the models of magnetic reconnection which are attepmted to be applied to astrophysical, solar or heliospheric environments. In…

Solar and Stellar Astrophysics · Physics 2015-05-30 Giovanni Lapenta , Alexander Lazarian

Especially in cold and high-density regions, the assumptions of ideal magnetohydrodynamics (MHD) can break down, making first order non-ideal terms such as Ohmic and ambipolar diffusion as well as the Hall effect important. In this study we…

Earth and Planetary Astrophysics · Physics 2023-07-25 Oliver Zier , Volker Springel , Alexander C. Mayer

This note studies classical magnetohydrodynamic shock waves in an inviscid fluidic plasma that is assumed to be a perfect conductor of heat as well as of electricity. For this mathematically prototypical material, it identifies a critical…

Analysis of PDEs · Mathematics 2015-05-21 Heinrich Freistuhler , Felix Kleber , Johannes Schropp

Massive galaxies at high redshift are predicted to be fed from the cosmic web by narrow, dense, cold streams. These streams penetrate supersonically through the hot medium encompassed by a stable shock near the virial radius of the…

Astrophysics of Galaxies · Physics 2016-09-20 Nir Mandelker , Dan Padnos , Avishai Dekel , Yuval Birnboim , Andreas Burkert , Mark R. Krumholz , Elad Steinberg

The scale locality of energy fluxes for magnetohydrodynamics (MHD) is investigated numerically for stationary states of turbulence. Two types of forces are used to drive turbulence, a kinetic force that acts only on the velocity field and a…

Fluid Dynamics · Physics 2015-05-30 B. Teaca , D. Carati , J. A. Domaradzki

By focusing on the oscillations of the cross-sectional area and the intensity of magnetic waveguides located in the lower solar atmosphere, we aim to detect and identify magnetohydrodynamic (MHD) sausage waves. Capturing several series of…

Solar and Stellar Astrophysics · Physics 2015-06-11 I. Dorotovic , R. Erdelyi , N. Freij , V. Karlovsky , I. Marquez

The characteristics of two-phase stratified magnetohydrodynamic (MHD) flow in horizontal rectangular ducts are investigated for a system consisting of a conductive liquid and a non-conductive gas. Numerical and analytical solutions of the…

Fluid Dynamics · Physics 2026-03-04 Subham Pal , Ilya Barmak , Arseniy Parfenov , Alexander Gelfgat , Neima Brauner

X-ray observations of merging clusters provide many examples of bow shocks leading merging subclusters. While the Mach number of a shock can be estimated from the observed density jump using Rankine-Hugoniot condition, it reflects only the…

Astrophysics of Galaxies · Physics 2018-10-16 Congyao Zhang , Eugene Churazov , William R. Forman , Christine Jones

The inverse transfer of magnetic helicity is a fundamental process which may explain large scale magnetic structure formation and sustainement. Until very recently, direct numerical simulations (DNS) of the inverse transfer in…

Plasma Physics · Physics 2024-07-29 Jean-Mathieu Teissier , Wolf-Christian Müller

We study the linear magnetohydrodynamic (MHD) equations, both in the Newtonian and the general-relativistic limit, as regards a viscous magnetized fluid of finite conductivity and discuss instability criteria. In addition, we explore the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 K. Kleidis , A. Kuiroukidis , D. B. Papadopoulos , L. Vlahos

The 6.7 GHz methanol maser is exclusively associated with high-mass star formation. However, it remains unclear what structures harbour the methanol masers. Cepheus A is one of the closest regions of massive star formation, making it an…

Solar and Stellar Astrophysics · Physics 2015-05-20 K. J. E. Torstensson , H. J. van Langevelde , W. H. T. Vlemmings , S. Bourke

Magnetohydrodynamical (MHD) turbulence is ubiquitous in magnetized astrophysical plasmas, and it radically changes a great variety of astrophysical processes. In this review, we give the concept of MHD turbulence and explain the origin of…

Solar and Stellar Astrophysics · Physics 2023-02-24 Elena Popova , Alexandre Lazarian

Rational large Reynolds number matched asymptotic expansions of three-dimensional nonlinear magneto-hydrodynamic (MHD) states are concerned. The nonlinear MHD states, assumed to be predominantly driven by a unidirectional shear, can be…

Fluid Dynamics · Physics 2019-05-01 Kengo Deguchi

We present an investigation of the velocity fields in early to late M-type star hydrodynamic models, and we simulate their influence on FeH molecular line shapes. The M star model parameters range between log g of 3.0 - 5.0 and Teff of 2500…

Solar and Stellar Astrophysics · Physics 2015-05-14 S. Wende , A. Reiners , H. -G. Ludwig