Ultraviolet spectroscopy of solar energetic particle source regions

2005 ◽  
Author(s):  
J. L. Kohl ◽  
S. Cranmer ◽  
R. Esser ◽  
L. D. Gardner ◽  
S. Fineschi ◽  
...  
Keyword(s):  
Energetic Particle ◽  
Solar Energetic Particle ◽  
Ultraviolet Spectroscopy ◽  
Particle Source ◽  
Source Regions

scholarly journals Long-lived energetic particle source regions on the Sun

2015 ◽  
Vol 642 ◽  
pp. 012002 ◽  
Author(s):  
R Bučík ◽  
D E Innes ◽  
N H Chen ◽  
G M Mason ◽  
R Gómez-Herrero ◽  
...  
Keyword(s):  
Energetic Particle ◽  
The Sun ◽  
Particle Source ◽  
Source Regions

scholarly journals Variable Ion Compositions of Solar Energetic Particle Events in the Inner Heliosphere: A Field Line Braiding Model with Compound Injections

2022 ◽  
Vol 924 (1) ◽  
pp. 22
Author(s):  
Fan Guo ◽  
Lulu Zhao ◽  
Christina M. S. Cohen ◽  
Joe Giacalone ◽  
R. A. Leske ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Energetic Particle ◽  
Radial Distance ◽  
Solar Energetic Particle ◽  
The Sun ◽  
Ion Composition ◽  
Source Regions ◽  
Solar Energetic Particle Events ◽  
Composition Ratios ◽  
Inner Heliosphere

Abstract We propose a model for interpreting highly variable ion composition ratios in solar energetic particle (SEP) events recently observed by the Parker Solar Probe (PSP) at 0.3–0.45 au. We use numerical simulations to calculate SEP propagation in a turbulent interplanetary magnetic field with a Kolmogorov power spectrum from large scales down to the gyration scale of energetic particles. We show that when the source regions of different species are offset by a distance comparable to the size of the source regions, the observed energetic particle composition He/H can be strongly variable over more than two orders of magnitude, even if the source ratio is at the nominal value. Assuming a 3He/4He source ratio of 10% in impulsive 3He-rich events and the same spatial offset of the source regions, the 3He/4He ratio at observation sites also vary considerably. The variability of the ion composition ratios depends on the radial distance, which can be tested by observations made at different radial locations. We discuss the implications of these results on the variability of ion composition of impulsive events and on further PSP and Solar Orbiter observations close to the Sun.

Source Regions of Major Solar Energetic Particle Events

2003 ◽  
Author(s):  
N. V. Nitta ◽  
E. W. Cliver ◽  
A. J. Tylka ◽  
P. Smit
Keyword(s):  
Energetic Particle ◽  
Solar Energetic Particle ◽  
Source Regions ◽  
Solar Energetic Particle Events

scholarly journals Strong non-radial propagation of energetic electrons in solar corona

2018 ◽  
Vol 614 ◽  
pp. A61 ◽  
Author(s):  
A. Klassen ◽  
N. Dresing ◽  
R. Gómez-Herrero ◽  
B. Heber ◽  
A. Veronig
Keyword(s):  
Magnetic Field ◽  
Solar Corona ◽  
Energetic Particle ◽  
Extreme Ultraviolet ◽  
Energetic Electron ◽  
Solar Energetic Particle ◽  
Source Surface ◽  
Energetic Electrons ◽  
Particle Source ◽  
Jet Trajectory

Analyzing the sequence of solar energetic electron events measured at both STEREO-A (STA) and STEREO-B (STB) spacecraft during 17–21 July 2014, when their orbital separation was 34°, we found evidence of a strong non-radial electron propagation in the solar corona below the solar wind source surface. The impulsive electron events were associated with recurrent flare and jet (hereafter flare/jet) activity at the border of an isolated coronal hole situated close to the solar equator. We have focused our study on the solar energetic particle (SEP) event on 17 July 2014, during which both spacecraft detected a similar impulsive and anisotropic energetic electron event suggesting optimal connection of both spacecraft to the parent particle source, despite the large angular separation between the parent flare and the nominal magnetic footpoints on the source surface of STA and STB of 68° and 90°, respectively. Combining the remote-sensing extreme ultraviolet (EUV) observations, in-situ plasma, magnetic field, and energetic particle data we investigated and discuss here the origin and the propagation trajectory of energetic electrons in the solar corona. We find that the energetic electrons in the energy range of 55–195 keV together with the associated EUV jet were injected from the flare site toward the spacecraft’s magnetic footpoints and propagate along a strongly non-radial and inclined magnetic field below the source surface. From stereoscopic (EUV) observations we estimated the inclination angle of the jet trajectory and the respective magnetic field of 63° ± 11° relative to the radial direction. We show how the flare accelerated electrons reach very distant longitudes in the heliosphere, when the spacecraft are nominally not connected to the particle source. This example illustrates how ballistic backmapping can occasionally fail to characterize the magnetic connectivity during SEP events. This finding also provides an additional mechanism (one among others), which may explain the origin of widespread SEP events.

scholarly journals Temperature of Source Regions of 3He-Rich Impulsive Solar Energetic Particle Events

2017 ◽  
Vol 13 (S335) ◽  
pp. 14-16 ◽  
Author(s):  
N.-H. Chen ◽  
R. Bučík ◽  
R.-S. Kim
Keyword(s):  
Energetic Particle ◽  
Emission Measure ◽  
Solar Energetic Particle ◽  
Heavy Ion ◽  
Solar Dynamics Observatory ◽  
Dissipation Process ◽  
Solar Source ◽  
Source Regions ◽  
Dem Analysis ◽  
Solar Dynamics

AbstractImpulsive solar energetic particle (SEP) events originate from the energy dissipation process in small solar flares. Anomalous abundances in impulsive SEP events provide an evidence on unique, yet unclear, acceleration mechanism. The pattern of heavy-ion enhancements indicates that the temperature of the source plasma that is accelerated is low and not flare-like. We examine the solar source of the 3He-rich SEP event of 2012 November 20 using Solar Dynamics Observatory (SDO)/ Atmospheric Imaging Assembly (AIA) images and investigate its thermal variation. The examined event is associated with recurrent coronal jets. The Differential Emission Measure (DEM) analysis is applied to study the temperature evolution/distribution of the source regions. Preliminary results show that the temperature of the associated solar source is ranged between 1.2-3.1 MK.

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