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Related papers: Ion-cyclotron waves in Solar Coronal Hole

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A statistical analysis of interstellar He+ pickup ion measurements from SOHO/CTOF combined with magnetic field data from WIND/MFI enable quantitative study of wave-particle interactions in the inner heliosphere for the first time. Magnetic…

Astrophysics · Physics 2007-05-23 L. Saul , E. Moebius , C. W. Smith , P. Bochsler , H. Gruenwaldt , B. Klecker , F. Ipavich

Electromagnetic cyclotron waves (ECWs) near the proton cyclotron frequency are frequently observed in the solar wind, yet their generation mechanism is still an open question. Based on the Wind data during the years 2005$-$2015, this paper…

Space Physics · Physics 2018-12-14 G. Q. Zhao , H. Q. Feng , D. J. Wu , G. Pi , J. Huang

We analyze the propagation of waves in sunspots from the photosphere to the chromosphere using time series of co-spatial Ca II H intensity spectra (including its line blends) and polarimetric spectra of Si I 10827 and the He I 10830…

Solar and Stellar Astrophysics · Physics 2015-05-19 T. Felipe , E. Khomenko , M. Collados , C. Beck

The ISWAT clusters H1+H2 have a focus on interplanetary space and its characteristics, especially on the large-scale co-rotating and transient structures impacting Earth. SIRs, generated by the interaction between high-speed solar wind…

The main goal of our present work is to provide, for the first time, a simple computational tool that can be used to compute the brightness, the spectral index, the polarization, the time variability and the spectrum of the non-thermal…

High Energy Astrophysical Phenomena · Physics 2009-03-25 D. Volpi , L. Del Zanna , E. Amato , N. Bucciantini

Plumes have been proposed to channel MHD waves and the solar wind into the heliosphere. High-speed propagating disturbances (PDs), though well detected in plumes, cannot yet be clearly assigned to MHD waves or to mass flows. Additionally,…

Solar and Stellar Astrophysics · Physics 2026-04-08 Ziwen Huang , L. P. Chitta , L. Teriaca , R. Aznar Cuadrado , H. Peter , S. K. Solanki , T. Wiegelmann , F. Plaschke

To investigate the interstellar medium (ISM) and Galactic cosmic rays (CRs) in the solar neighborhood, we analyzed ${\gamma}$-ray data by Fermi Large Area Telescope (LAT) for five nearby molecular cloud regions. Our data includes the…

High Energy Astrophysical Phenomena · Physics 2025-06-23 Tsunefumi Mizuno , Katsuhiro Hayashi , Hinako Ochi , Igor V. Moskalenko , Elena Orlando , Andrew W. Strong

We for the first time propose a physical model of the precursor (PR) and interpulse (IP) components of the radio pulsar profiles. It is based on propagation effects in the secondary plasma flow of a pulsar. The components are suggested to…

Astrophysics of Galaxies · Physics 2009-04-28 S. A. Petrova

Coronal plumes are long, ray-like, open structures, which have been considered as possible sources for the solar wind. Their origin in the largely unipolar coronal holes has long been a mystery. Earlier spectroscopic and imaging…

Solar and Stellar Astrophysics · Physics 2022-07-06 Pankaj Kumar , Judith T. Karpen , Vadim M. Uritsky , Craig E. Deforest , Nour E. Raouafi , C. Richard DeVore

The solar wind upstream of Mars's bow shock can be described in terms of Alfv\'enic turbulence, with an incompressible energy cascade rate of $10^{-17}$ J m$^{-3}$ s$^{-1}$ at magnetohydrodynamics (MHD) scales. The solar wind has more…

Solar and Stellar Astrophysics · Physics 2024-06-26 Norberto Romanelli , Christopher M. Fowler , Gina A. DiBraccio , Jared R. Espley , Jasper S. Halekas

Using one-dimensional hybrid expanding box model we investigate properties of the solar wind in the outer heliosphere. We assume a proton-electron plasma with a strictly transverse ambient magnetic field and, beside the expansion, we take…

Solar and Stellar Astrophysics · Physics 2016-11-17 Petr Hellinger , Pavel M. Travnicek

Radio synchrotron polarization maps of the Galaxy can be used to infer the properties of interstellar turbulence in the diffuse warm ionized medium (WIM). In this paper, we investigate the spatial gradient of linearly polarized synchrotron…

The dissipation of magnetized turbulence is an important paradigm for describing heating and energy transfer in astrophysical environments such as the solar corona and wind; however, the specific collisionless processes behind dissipation…

Well-known analytical results dealing with ion cyclotron and drift waves and which follow from the kinetic theory are used and the dispersion equation, which describes coupled two modes, is solved numerically. The numerical results obtained…

Astrophysics · Physics 2009-11-13 J. Vranjes , S. Poedts

Spicules are small hairy like structures seen at the solar limb mainly at chromospheric and transition region lines. They generally live for 3-10 minutes. We observe these spicules in a south polar region of the Sun with a coordinated…

Solar and Stellar Astrophysics · Physics 2015-12-16 Tanmoy Samanta , Vaibhav Pant , Dipankar Banerjee

Global coronal waves (CWs) and their interaction with coronal holes (CHs) result, among other effects, in the formation of reflected and transmitted waves. Observations of such events provide us with measurements of different CW parameters,…

Solar and Stellar Astrophysics · Physics 2020-09-02 I. Piantschitsch , J. Terradas , M. Temmer

Over the last few decades, different types of plasma waves (e.g., the ion acoustic waves (IAWs), electrostatic solitary waves (ESWs), upper/lower hybrid waves, the Langmuir waves etc.) have been observed in the upstream, downstream and ramp…

Plasma Physics · Physics 2023-02-01 Manpreet Singh , Federico Fraschetti , Joe Giacalone

Recent observations revealed that the solar atmosphere is highly structured in density, temperature and magnetic field. The presence of these gradients may lead to the appearance of currents in the plasma, which in the weakly collisional…

Astrophysics · Physics 2009-11-13 R. Mecheri , E. Marsch

A comparison between a Coronal Hole (CH) and the adjacent Quiet-Sun (QS) has been performed using spectroscopic diagnostics of Hinode/ the EUV Imaging Spectrometer (EIS). Coronal funnels play an important role in the formation and…

Solar and Stellar Astrophysics · Physics 2015-11-04 P. Kayshap , D. Banerjee , A. K. Srivastava

This paper presents results of comparison between observations of coronal holes in the UV (SOHO EIT) and microwave emission (17, 5.7 GHz, 327 and 150.9 MHz, NoRH, SSRT and Nancy radioheliographs), and solar wind parameters, according to the…

Solar and Stellar Astrophysics · Physics 2015-05-20 D. Prosovetsky , I. Myagkova
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