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Related papers: Velocity Profiles in the Solar Corona from Multi-I…

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We combine observations of the Coronal Multi-channel Polarimeter (CoMP) and the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) to study the characteristic properties of (propagating) Alfvenic motions and…

Solar and Stellar Astrophysics · Physics 2015-07-02 Jiajia Liu , Scott W. McIntosh , Ineke De Moortel , Yuming Wang

Radio continuum observations of external galaxies provide us with an excellent outside view on the distribution of cosmic-ray electrons in the disc and halo. In this review, we summarise the current state of what we have learned from…

Astrophysics of Galaxies · Physics 2021-12-16 Volker Heesen

Robustly identifying the solar sources of individual packets of solar wind measured in interplanetary space remains an open problem. We set out to see if this problem is easier to tackle using solar wind measurements closer to the Sun than…

Solar and Stellar Astrophysics · Physics 2018-11-21 D. Stansby , T. S. Horbury , L. Matteini

The Sun's outer atmosphere is heated to temperatures of millions of degrees, and solar plasma flows out into interplanetary space at supersonic speeds. This paper reviews our current understanding of these interrelated problems: coronal…

Solar and Stellar Astrophysics · Physics 2017-10-11 Steven R. Cranmer , Sarah E. Gibson , Pete Riley

Persistent outflows have recently been detected at boundaries of some active regions. Although these outflows are suggested to be possible sources of the slow solar wind, the nature of these outflows is poorly understood. Through an…

Solar and Stellar Astrophysics · Physics 2015-05-19 L. -J. Guo , H. Tian , J. -S. He

The hot and diffuse nature of the Sun's extended atmosphere allows it to persist in non-equilibrium states for long enough that wave-particle instabilities can arise and modify the evolution of the expanding solar wind. Determining which…

For the first time, we report a large-scale wave that was observed simultaneously in the photosphere, chromosphere, transition region and low corona layers of the solar atmosphere. Using the high temporal and high spatial resolution…

Solar and Stellar Astrophysics · Physics 2015-06-05 Yuandeng Shen , Yu Liu

Data obtained from Parker Solar Probe (PSP) since 2021 April have shown the first in situ observation of the solar corona, where the solar wind is formed and accelerated. Here we investigate the alpha-proton differential flow and its…

Solar and Stellar Astrophysics · Physics 2024-01-22 Hao Ran , Ying D. Liu , Chong Chen , Parisa Mostafavi

The role of interchange reconnection as a drive mechanism for the solar wind is explored by solving the global magnetic-field-aligned equations describing wind acceleration. Boundary conditions in the low corona, including a…

Solar and Stellar Astrophysics · Physics 2023-08-16 J. F. Drake , S. D. Bale , M. Swisdak , N. E. Raouafi , M. Velli

The relationship between the peak velocities of high-speed solar wind streams near Earth and the areas of their solar source regions, i.e., coronal holes, has been known since the 1970s, but it is still physically not well understood. We…

Solar and Stellar Astrophysics · Physics 2020-07-10 Stefan J. Hofmeister , Astrid M. Veronig , Stefaan Poedts , Evangelia Samara , Jasmina Magdalenic

We identify and examine the solar wind intervals near the sonic critical point (i.e., $M_S \sim 1$) observed by the Parker Solar Probe (PSP). The near subsonic wind intervals show similar properties: a low density, an extremely low…

Solar and Stellar Astrophysics · Physics 2024-04-16 Wenshuai Cheng , Ying D. Liu , Hao Ran , Yiming Jiao , Michael L. Stevens , Justin C. Kasper

We have shown previously that SOHO/UVCS data allow us to detect active region (AR) outflows at coronal altitudes higher than those reached by other instrumentation. These outflows are thought to be a component of the slow solar wind. Our…

Solar and Stellar Astrophysics · Physics 2016-10-07 L. Zangrilli , G. Poletto

The global rotational profile of the solar atmosphere and its variation at different layers, although crucial for a comprehensive understanding of the dynamics of the solar magnetic field, has been a subject to contradictory results…

Solar wind back-mapping is a combination of ballistic mapping and magnetic mapping. By examining the different model ingredients that can affect the derived back-mapped position, we aim to provide a more precise estimate of the source…

Solar and Stellar Astrophysics · Physics 2025-02-12 Alexandros Koukras , Laurent Dolla , Rony Keppens

We present a novel method to evaluate the Alfven speed and the magnetic field strength along the streamer plasma sheet in the outer corona. The method is based on recent observations of streamer waves, which are regarded as the fast kink…

Solar and Stellar Astrophysics · Physics 2015-05-20 Y. Chen , S. W. Feng , B. Li , H. Q. Song , L. D. Xia , X. L. Kong , Xing Li

Wave theories of heating the chromosphere, corona, and solar wind due to photospheric fluctuations are strengthened by the existence of observed wave coherency up to the transition region (TR). The coherency of solar spicules' intensity…

Solar and Stellar Astrophysics · Physics 2017-02-08 Alireza Ahangarzadeh Maralani , Ehsan Tavabi , Ali Ajabshirizadeh

Coronal holes (CHs) are regions of open magnetic flux which are the source of high speed solar wind (HSSW) streams. To date, it is not clear which aspects of CHs are of most influence on the properties of the solar wind as it expands…

Solar and Stellar Astrophysics · Physics 2018-12-12 Tadhg M. Garton , Sophie A. Murray , Peter T. Gallagher

It is shown that the connection of sufficiently fast flows with dynamical channels for particle escape in the Solar Corona is rather direct: it depends on their ability to deform (in specific cases to distort) the ambient magnetic field…

In this paper, I review the results of 3-D evolution of the inner heliosphere over the solar cycle #23, based on observations of interplanetary scintillation (IPS) made at 327 MHz using the Ooty Radio Telescope. The large-scale features of…

Solar and Stellar Astrophysics · Physics 2011-04-04 P. K. Manoharan

As the global magnetic field of the Sun has an activity cycle, one expects to observe some variation of the dynamical properties of the flows visible in the photosphere. We investigate the flow field during the solar cycle by analysing…

Solar and Stellar Astrophysics · Physics 2017-02-15 Th. Roudier , J. M. Malherbe , G. M. Mirouh
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