English
Related papers

Related papers: Kinetic range spectral features of cross-helicity …

200 papers

Strong incompressible three-dimensional magnetohydrodynamic turbulence is investigated by means of high resolution direct numerical simulations. The simulations show that the configuration space is characterized by regions of positive and…

Astrophysics · Physics 2009-01-16 Jean C Perez , Stanislav Boldyrev

Kinetic helicity is a fundamental characteristics of astrophysical turbulent flows. It is not only responsible for the generation of large-scale magnetic fields in the Sun, stars, and spiral galaxies, but it also affects turbulent diffusion…

Fluid Dynamics · Physics 2025-05-15 Igor Rogachevskii , Nathan Kleeorin , Axel Brandenburg

We develop a two-scale formalism to determine global magnetic helicity spectra in systems where the local magnetic helicity has opposite signs on both sides of the equator, giving rise to cancelation with conventional methods. We verify…

Solar and Stellar Astrophysics · Physics 2017-02-07 Axel Brandenburg , Gordon J. D. Petrie , Nishant K. Singh

Magnetoseismology, a technique of magnetic field diagnostics based on observations of magnetohydrodynamic (MHD) waves, has been widely used to estimate the field strengths of oscillating structures in the solar corona. However, previously…

Solar and Stellar Astrophysics · Physics 2020-11-05 Zihao Yang , Hui Tian , Steven Tomczyk , Richard Morton , Xianyong Bai , Tanmoy Samanta , Yajie Chen

We analyze the spectral properties of driven, supersonic compressible magnetohydrodynamic (MHD) turbulence obtained via high-resolution numerical experiments, for application to understanding the dynamics of giant molecular clouds. Via…

Astrophysics · Physics 2009-11-07 Jason G. Vestuto , Eve C. Ostriker , James M. Stone

Correlation analysis is obtained among Faraday rotation measure, HI column density, thermal and synchrotron radio brightness using archival all-sky maps of the Galaxy. A method is presented to calculate the magnetic strength and its…

Astrophysics of Galaxies · Physics 2019-08-29 Y. Sofue , H. Nakanishi , K. Ichiki

We use a nonstationary generalization of the higher-order structure function technique to investigate statistical properties of the magnetic field fluctuations recorded by MESSENGER spacecraft during its first flyby (01/14/2008) through the…

The anisotropy of magnetophydrodynamic turbulence is investigated by using solar wind data from the Helios 2 spacecraft. We investigate the behaviour of the complete high-order moment tensors of magnetic field increments and we compare the…

Space Physics · Physics 2009-11-13 Luca Sorriso-Valvo , Vincenzo Carbone , Roberto Bruno , Pierluigi Veltri

Using direct numerical simulations (DNS) we verify that in the kinematic regime, a turbulent helical dynamo grows in such a way that the magnetic energy spectrum remains to high precision shape-invariant, i.e., at each wavenumber $k$ the…

Astrophysics of Galaxies · Physics 2014-10-24 Kandaswamy Subramanian , Axel Brandenburg

Magnetic dipolar mode or magnetostatic (MS) oscillations in ferrite samples have the wavelength much smaller than the electromagnetic wavelength at the same frequency and, at the same time, much larger than the exchange interaction spin…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 E. O. Kamenetskii , R. Shavit , M. Sigalov

We compute for the first time magnetic helicity and energy spectra of the solar active region NOAA 11158 during 11-15 February 2011 at 20^o southern heliographic latitude using observational photospheric vector magnetograms. We adopt the…

Solar and Stellar Astrophysics · Physics 2014-03-25 Hongqi Zhang , Axel Brandenburg , D. D. Sokoloff

The dynamics of the upper mesosphere of Venus (~85-115 km) have been characterized as a combination of a retrograde superrotating zonal wind (RSZ) with a subsolar-to-antisolar flow (SSAS). Numerous mm-wave single-dish observations have been…

Earth and Planetary Astrophysics · Physics 2015-06-04 A. Moullet , E. Lellouch , R. Moreno , M. Gurwell , H. Sagawa

Scalar fields like dilaton appear in quantum field theory (QFT) due to scale symmetry breaking. Their appeal also extends to modified theories of gravity, like $F(R)$ gravity, Horva Lifshitz gravity etc. In unified theories they make their…

High Energy Astrophysical Phenomena · Physics 2021-02-02 Ankur Chaubey , Manoj K. Jaiswal , Avijit K. Ganguly

Unconfined relativistic outflows from rotating, magnetized compact objects are often well-modeled by assuming the field geometry is approximately a split-monopole at large radii. Earlier work has indicated that such an unconfined flow has…

High Energy Astrophysical Phenomena · Physics 2009-11-29 Alexander Tchekhovskoy , Jonathan C. McKinney , Ramesh Narayan

Magnetic holes (MHs) are coherent magnetic field dips whose size ranges from fluid to kinetic scale, ubiquitously observed in the heliosphere and in planetary environments. Despite the longstanding effort in interpreting the abundance of…

Solar and Stellar Astrophysics · Physics 2024-10-21 Giuseppe Arrò , Francesco Califano , Francesco Pucci , Tomas Karlsson , Hui Li

Helicity measures complexity in the field. Magnetic helicity is given by a volume integral over the scalar product of magnetic field {\bf B} and its vector potential {\bf A}. A direct computation of magnetic helicity in the solar atmosphere…

Solar and Stellar Astrophysics · Physics 2015-05-20 Sanjiv Kumar Tiwari

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 aim of this study is to simulate the interaction of the solar wind with the Hermean magnetosphere when the interplanetary magnetic field is weak, performing a parametric study for all the range of hydrodynamic values of the solar wind…

Earth and Planetary Astrophysics · Physics 2016-08-15 J. Varela , F. Pantellini , M. Moncuquet

The transport of energetic particles such as Cosmic Rays is governed by the properties of the plasma being traversed. While these properties are rather poorly known for galactic and interstellar plasmas due to the lack of in situ…

Solar and Stellar Astrophysics · Physics 2014-06-03 Tobias Wiengarten , Jens Kleimann , Horst Fichtner , Patrick Kühl , Andreas Kopp , Bernd Heber , Ralf Kissmann

The relation of the solar surface magnetic field with mesogranular cells is studied using high spatial (~ 100 km) and temporal (~ 30 sec) resolution data obtained with the IMaX instrument aboard SUNRISE. First, mesogranular cells are…

‹ Prev 1 8 9 10 Next ›