Publications (26)
Spectral characteristic of mid-term quasi-periodicities in sunspots data
P. Frick, D. Sokoloff, R. Stepanov +2
Numerous analyses suggest the existence of various quasi-periodicities in solar activity. The power spectrum of solar activity recorded in sunspot data is dominated by the 11…
A non local shell model of turbulent dynamo
F. Plunian, R. Stepanov
We derive a new shell model of magnetohydrodynamic (MHD) turbulence in which the energy transfers are not necessary local. Like the original MHD equations, the model conserves the…
Neural Differential Equations for the Solar Dynamo
E. Illarionov, R. Stepanov, K. M. Kuzanyan +1
Physical models aimed to reproduce basic features of the solar sunspot cycle are typically based on the solar dynamo mechanism. Usually qualitative arguments are used to define par…
Phase coherence and phase jumps in the Schwabe cycle
F. Stefani, J. Beer, A. Giesecke +4
Guided by the working hypothesis that the Schwabe cycle of solar activity is synchronized by the 11.07 years alignment cycle of the tidally dominant planets Venus, Earth and Jupite…
Recognizing magnetic structures by present and future radio telescopes with Faraday rotation measure synthesis
R. Beck, P. Frick, R. Stepanov +1
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 m…
Wavelet analysis of the long-term activity of V833 Tau
R. Stepanov, N. I. Bondar', M. M. Katsova +2
The bulk of available stellar activity observations is frequently checked for the manifestation of signs in comparison with the known characteristic of solar magnetic modulation. T…
Analysis of spiral arms using anisotropic wavelets: gas, dust and magnetic fields in M51
I. Patrikeev, A. Fletcher, R. Stepanov +4
We have developed a technique of isolating elongated structures in galactic images, such as spiral arms, using anisotropic wavelets and apply this to maps of the CO, infrared and r…
Wavelet tomography of the Galactic magnetic field. I. The method
R. Stepanov, P. Frick, A. Shukurov +1
We suggest a two-dimensional wavelet devised to deduce the large-scale structure of a physical field (e.g., the Galactic magnetic field) from its integrals along straight paths fro…
Current helicity and magnetic field anisotropy in solar active regions
H. Xu, R. Stepanov, K. Kuzanyan +3
The electric current helicity density contains six terms, where are components of the magnetic f…
Testing the magnetic field models of galaxies with the SKA
T. G. Arshakian, R. Stepanov, R. Beck +2
The future new-generation radio telescope SKA (Square Kilometre Array) and its precursors will provide a rapidly growing number of polarized radio sources. Hundred and thousands po…
Dissipation scales of kinetic helicities in turbulence
T. Lessinnes, F. Plunian, R. Stepanov +1
A systematic study of the influence of the viscous effect on both the spectra and the nonlinear fluxes of conserved as well as non conserved quantities in Navier-Stokes turbulence…
Full perturbation solution for the flow in a rotated torus
A. Chupin, R. Stepanov
We present a perturbation solution for a pressure-driven fluid flow in a rotating toroidal channel. The analysis shows the difference between the solutions of full and simplified e…
Schwabe, Gleissberg, Suess-de Vries: Towards a consistent model of planetary synchronization of solar cycles
F. Stefani, A. Giesecke, M. Seilmayer +2
Aiming at a consistent planetary synchronization model of both short-term and long-term solar cycles, we start with an analysis of Schove's historical data of cycle maxima. Their d…
Cross helicity sign reversals in the dissipative scales of magnetohydrodynamic turbulence
V. Titov, R. Stepanov, N. Yokoi +2
We perform direct numerical simulations of magnetohydrodynamic (MHD) turbulence with kinetic energy and cross helicity injections at large scales. We observe that the cross helicit…
Comparison of algorithms for determination of rotation measure and Faraday structure I. 1100 - 1400 MHz
X. H. Sun, L. Rudnick, Takuya Akahori +14
(abridged) We run a Faraday structure determination data challenge to benchmark the currently available algorithms including Faraday synthesis (previously called RM synthesis in th…
Exploring the magnetic fields in local and distant galaxies
T. G. Arshakian, R. Stepanov, R. Beck +3
(abridged) We investigate the possibility to recognize the magnetic field structures in nearby galaxies and to test the cosmological evolution of their large- and small-scale magne…
Magnetic and gaseous spiral arms in M83
P. Frick, R. Stepanov, R. Beck +4
Isotropic and anisotropic wavelet transforms are used to decompose the images of the spiral galaxy M83 in various tracers to quantify structures in a range of scales from 0.2 to 10…
On the effects of turbulence on a screw dynamo
K. -H. Raedler, R. Stepanov
In an experiment in the Institute of Continuous Media Mechanics in Perm (Russia) an non--stationary screw dynamo is intended to be realized with a helical flow of liquid sodium in…
Wavelet differentiation of a noisy signal
I. Patrickeyev, R. Stepanov, P. Frick
Several differentiating algorithms of the noisy signals are considered. The proposed wavelet based technique is compared with others based on the Fourier transform and the finite d…
Faraday Rotation Measure Synthesis for Magnetic Fields of Galaxies
P. Frick, D. Sokoloff, R. Stepanov +1
RM Synthesis was recently developed as a new tool for the interpretation of polarized emission data in order to separate the contributions of different sources lying on the same li…
The relation between magnetic and material arms in models for spiral galaxies
D. Moss, R. Beck, D. Sokoloff +3
Context. Observations of polarized radio emission show that large-scale (regular) magnetic fields in spiral galaxies are not axisymmetric, but generally stronger in interarm region…
Helicity detection of the astrophysical magnetic fields from radio emission statistics
A. Volegova, R. Stepanov
We discuss inverse problem of detection turbulence magnetic field helical properties using radio survey observations statistics. In this paper, we present principal solution which…
Structures in the RM sky
P. Frick, R. Stepanov, A. Shukurov +1
Coherent structures in the distribution of the Faraday rotation measure of extragalactic radio sources are isolated using wavelet transformation technique. Signatures of the magnet…
Modeling the total and polarized emission in evolving galaxies: "spotty" magnetic structures
T. G. Arshakian, R. Stepanov, R. Beck +2
Future radio observations with the SKA and its precursors will be sensitive to trace spiral galaxies and their magnetic field configurations up to redshift . We suggest…
Wavelet-based Faraday Rotation Measure Synthesis
P. Frick, D. Sokoloff, R. Stepanov +1
Faraday Rotation Measure (RM) Synthesis, as a method for analyzing multi-channel observations of polarized radio emission to investigate galactic magnetic fields structures, requir…
Numerical simulation of tidal synchronization of the large-scale circulation in Rayleigh-Bénard convection with aspect ratio 1
S. Röhrborn, P. Jüstel, V. Galindo +2
A possible explanation for the apparent phase stability of the 11.07-year Schwabe cycle of the solar dynamo was the subject of a series of recent papers. The synchronization of the…