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In this work, we perform a statistical study of magnetic field fluctuations in the solar wind at 1 au using permutation entropy and complexity analysis, and the investigation of the temporal variations of the Hurst exponents. Slow and fast…

Solar and Stellar Astrophysics · Physics 2024-03-26 Emilia Kilpua , Simon Good , Matti Ala-Lahti , Adnane Osmane , Venla Koikkalainen

Magnetic field fluctuations measured in the heliosheath by the Voyager spacecraft are often characterized as compressible, as indicated by a strong fluctuating component parallel to the mean magnetic field. However, the interpretation of…

Space Physics · Physics 2024-08-01 L. -L. Zhao , G. P. Zank , M. Opher , B. Zieger , H. Li , V. Florinski , L. Adhikari , X. Zhu , M. Nakanotani

Accurate space weather forecasting requires knowledge of the trajectory of coronal mass ejections (CMEs), including any deflections close to the Sun or through interplanetary space. Kay et al. 2013 introduced ForeCAT, a model of CME…

Solar and Stellar Astrophysics · Physics 2015-06-03 C. Kay , M. Opher , R. M. Evans

Magnetic flux ropes (MFRs) are one kind of fundamental structures in the solar physics, and involved in various eruption phenomena. Twist, characterizing how the magnetic field lines wind around a main axis, is an intrinsic property of…

Solar and Stellar Astrophysics · Physics 2017-02-01 Yuming Wang , Bin Zhuang , Qiang Hu , Rui Liu , Chenglong Shen , Yutian Chi

Several studies have reported magnetic field fluctuations associated with umbral shock waves. We aim to study the properties and origin of magnetic field fluctuations in the umbral chromosphere. Temporal series of spectropolarimetric…

Solar and Stellar Astrophysics · Physics 2023-08-09 T. Felipe , S. J. González Manrique , C. R. Sangeetha , A. Asensio Ramos

The radial structure of the continuous spectrum of shear Alfven waves is calculated in this paper within the separatrix of a magnetic island. Geometrical effects due to the noncircularity of the flux surface's cross section are retained to…

Plasma Physics · Physics 2015-05-20 Alessandro Biancalani , Liu Chen , Francesco Pegoraro , Fulvio Zonca

The Millimeter-wave Intensity Mapping Experiment (mmIME) recently reported a detection of excess spatial fluctuations at a wavelength of 3 mm, which can be attributed to unresolved emission of several CO rotational transitions between…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-20 Patrick C. Breysse , Shengqi Yang , Rachel S. Somerville , Anthony R. Pullen , Gergö Popping , Abhishek S. Maniyar

We employ the DAVE (differential affine velocity estimator, Schuck 2005; 2006) tracking technique on a time series of MDI/1m high spatial resolution line- of-sight magnetograms to measure the photospheric flow velocity for three newly…

Solar and Stellar Astrophysics · Physics 2015-05-20 Lirong Tian , Pascal Démoulin , David Alexander , Chunming Zhu

Some techniques for the study of intermittency by means of wavelet transforms, are presented on an example of synthetic turbulent signal. Several features of the turbulent field, that cannot be probed looking at standard structure function…

chao-dyn · Physics 2007-05-23 Piero Olla , Paolo Paradisi

The ubiquitous presence of filamentary structures in the interstellar medium asks for an unbiased characterization of their properties including a stability analysis. We propose a novel technique to measure the spectrum of filaments in any…

Astrophysics of Galaxies · Physics 2018-12-19 Volker Ossenkopf-Okada , Rodion Stepanov

Understanding turbulence in interplanetary coronal mass ejections (ICMEs) is fundamental to space plasma research and critical for assessing the impact of space weather on geospace. Turbulence governs energy cascade, plasma heating,…

Solar and Stellar Astrophysics · Physics 2026-04-29 Shibotosh Biswas , Ankush Bhaskar , SG Abitha , Omkar Dhamane , Sanchita Pal , Dibyendu Chakrabarty , Vipin K Yadav

We report an experimental investigation of the statistical time dynamic of spatial Fourier modes in a fully developped turbulent jet flow. Measurements rely on an original acoustic scattering technique, allowing the direct and continuous…

Statistical Mechanics · Physics 2009-11-11 C. Poulain , N. Mazellier , Y. Gagne , C. Baudet

In a recent paper we presented a linear scaling Kohn-Sham density functional theory (DFT) code based on Daubechies wavelets, where a minimal set of localized support functions is optimized in situ and therefore adapted to the chemical…

Materials Science · Physics 2015-10-08 Laura E. Ratcliff , Luigi Genovese , Stephan Mohr , Thierry Deutsch

We investigate whether the method of wavelet-based Faraday rotation measure (RM) Synthesis can help us to identify structures of regular and turbulent magnetic fields in extended magnetized objects, such as galaxies and galaxy clusters.…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 R. Beck , P. Frick , R. Stepanov , D. Sokoloff

Emission in spectral lines can provide unique information on interstellar turbulence. Doppler shifts due to supersonic motions contain information on turbulent velocity field which is otherwise difficult to measure. However, the problem of…

Astrophysics · Physics 2016-08-30 A. Lazarian

The rich structure that we observe in molecular clouds is due to the interplay between strong magnetic fields and supersonic (turbulent) velocity fluctuations. The velocity fluctuations interact with the magnetic field, causing it too to…

Astrophysics of Galaxies · Physics 2020-08-12 James R. Beattie , Christoph Federrath , Amit Seta

We present the results of a multi-wavelength multi-epoch survey of five evolved protoplanetary disks in the IC 348 cluster that show significant infrared variability. Using 3-8micron and 24micron photometry along with 5-40micron…

Astrophysics of Galaxies · Physics 2015-06-04 Kevin Flaherty , James Muzerolle , George Rieke , Robert Gutermuth , Zoltan Balog , William Herbst , S. T. Megeath , Maria Kun

The interstellar medium (ISM) of our Galaxy is magnetized, compressible and turbulent, influencing many key ISM properties, like star formation, cosmic ray transport, and metal and phase mixing. Yet, basic statistics describing…

Astrophysics of Galaxies · Physics 2025-05-15 James R. Beattie , Christoph Federrath , Ralf S. Klessen , Salvatore Cielo , Amitava Bhattacharjee

It is currently believed that the turbulent fluctuations pervade the outermost heliosphere. Turbulence, magnetic reconnection, and their link may be responsible for magnetic energy conversion in these regions. The governing mechanisms of…

We report 3D numerical simulations of the flow of an electrically conducting fluid in a spherical shell when a magnetic field is applied. Different spherical Couette configurations are investigated, by varying the rotation ratio between the…

Fluid Dynamics · Physics 2015-05-28 Christophe Gissinger , Hantao Ji , Jeremy Goodman