scholarly journals Time evolution of stream interaction region energetic particle spectra in the inner heliosphere

2021 ◽  
Author(s):  
C. J. Joyce ◽  
D. J. McComas ◽  
N. A. Schwadron ◽  
E. R. Christian ◽  
M. E. Wiedenbeck ◽  
...  
Keyword(s):  
Time Evolution ◽  
Energetic Particle ◽  
Interaction Region ◽  
Particle Spectra ◽  
Inner Heliosphere

scholarly journals Investigating the longitude dependence of solar energetic particle spectra

2012 ◽  
Author(s):  
C. M. S. Cohen ◽  
G. M. Mason ◽  
R. A. Mewaldt ◽  
R. A. Leske
Keyword(s):  
Energetic Particle ◽  
Solar Energetic Particle ◽  
Particle Spectra

First Results from Solar Orbiter’s Energetic Particle Detector

2021 ◽  
Author(s):  
Javier Rodriguez-Pacheco ◽  
Keyword(s):  
Energetic Particle ◽  
Wide Energy Range ◽  
High Temporal Resolution ◽  
The Sun ◽  
Particle Detector ◽  
First Results ◽  
Wide Energy ◽  
Spatio Temporal ◽  
Inner Heliosphere

<p>In this presentation, we will show the first measurements performed by EPD since the end of the commissioning phase until the latest results obtained. During these months EPD has been scanning the inner heliosphere at different heliocentric distances and heliolongitues allowing - together with other spacecraft - to investigate the spatio-temporal behavior of the particle populations in the inner heliosphere during solar minimum conditions. Solar Orbiter was launched from Cape Canaveral on February 10th, 2020, thus beginning the journey to its encounter with the Sun. Solar Orbiter carries ten scientific instruments, six remote sensing and four in situ, that will allow the mission main goal: how the Sun creates and controls the heliosphere. Among the in situ instruments, the Energetic Particle Detector (EPD) measures electrons, protons and heavy ions with high temporal resolution over a wide energy range, from suprathermal energies up to several hundreds of MeV/nucleon.</p>

Energetic Particle Environment near the Sun from Parker Solar Probe

2020 ◽  
Author(s):  
Nathan Schwadron ◽  
Keyword(s):  
Energetic Particle ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Radiation Environment ◽  
The Sun ◽  
Particle Radiation ◽  
Integrated Science ◽  
Direct Observations ◽  
Interaction Regions ◽  
Inner Heliosphere

<p>NASA’s Parker Solar Probe (PSP) mission recently plunged through the inner heliosphere to perihelia at ~24 million km (~35 solar radii), much closer to the Sun than any prior human made object. Onboard PSP, the Integrated Science Investigation of the Sun (ISʘIS) instrument suite made groundbreaking measurements of solar energetic particles (SEPs). Here we discuss the near-Sun energetic particle radiation environment over PSP’s first two orbits, which reveal where and how energetic particles are energized and transported. We find a great variety of energetic particle events accelerated both locally and remotely. These include co-rotating interaction regions (CIRs), “impulsive” SEP events driven by acceleration near the Sun, and events related to Coronal Mass Ejections (CMEs). These ISʘIS observations made so close to the Sun provide critical information for investigating the near-Sun transport and energization of solar energetic particles that was difficult to resolve from prior observations. We discuss the physics of particle acceleration and transport in the context of various theories and models that have been developed over the past decades. This study marks a major milestone with humanity’s reconnaissance of the near-Sun environment and provides the first direct observations of the energetic particle radiation environment in the region just above the corona.</p>

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.

scholarly journals Study of Time Evolution of the Bend-over Energy in the Energetic Particle Spectrum at a Parallel Shock

2019 ◽  
Vol 877 (2) ◽  
pp. 97 ◽  
Author(s):  
F.-J. Kong ◽  
G. Qin ◽  
S.-S. Wu ◽  
L.-H. Zhang ◽  
H.-N. Wang ◽  
...  
Keyword(s):  
Time Evolution ◽  
Energetic Particle ◽  
Particle Spectrum

THE THREE-DIMENSIONAL MORPHOLOGY OF A COROTATING INTERACTION REGION IN THE INNER HELIOSPHERE

2009 ◽  
Vol 708 (2) ◽  
pp. L89-L94 ◽  
Author(s):  
B. E. Wood ◽  
R. A. Howard ◽  
A. Thernisien ◽  
D. G. Socker
Keyword(s):  
Three Dimensional ◽  
Interaction Region ◽  
Corotating Interaction Region ◽  
Inner Heliosphere

scholarly journals Cosmic ray production and emission in M82

2011 ◽  
Vol 7 (S284) ◽  
pp. 397-399
Author(s):  
Tova Yoast-Hull ◽  
John Everett ◽  
J. S. Gallagher ◽  
Ellen Zweibel
Keyword(s):  
Interstellar Medium ◽  
First Principles ◽  
Energetic Particle ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
Injection Rate ◽  
Starburst Galaxy ◽  
Nearby Galaxy ◽  
Electron Positron ◽  
Particle Spectra

AbstractStarting from first principles, we construct a simple model for the evolution of energetic particles produced by supernovae in the starburst galaxy M82. The supernova rate, geometry, and properties of the interstellar medium are all well observed in this nearby galaxy. Assuming a uniform interstellar medium and constant cosmic-ray injection rate, we estimate the cosmic-ray proton and primary & secondary electron/positron populations. From these particle spectra, we predict the gamma ray flux and the radio synchrotron spectrum. The model is then compared to the observed radio and gamma-ray spectra of M82 as well as previous models by Torres (2004), Persic et al. (2008), and de Cea del Pozo et al. (2009). Through this project, we aim to build a better understanding of the calorimeter model, in which energetic particle fluxes reflect supernova rates, and a better understanding of the radio-FIR correlation in galaxies.

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