High-energy gamma radiation of solar flares as an indicator of acceleration of energetic protons

Kurt, V. G.; Yushkov, B. Yu.; Kudela, K.; Галкин, В. И.

doi:10.1134/s0010952510010053

Cited by 24 publications

(18 citation statements)

References 20 publications

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“…The flares for which pion decay emission and neutrons were directly detected in space are listed in Table 6.2 Kurt et al 2010b). Note that only 5 flares listed in Table 6.2, were followed by registered GLEs.…”

Section: Neutron Production In Solar Flaresmentioning

confidence: 99%

Solar Cosmic Rays

Miroshnichenko

2015

Astrophysics and Space Science Library

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Section: Neutron Production In Solar Flaresmentioning

confidence: 99%

Solar Cosmic Rays

Miroshnichenko

2015

Astrophysics and Space Science Library

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“…Mewaldt et al (2005) estimated the total energetics of nonthermal interplanetary particles (including electrons, protons and ions) to be ≈ 6 × 10 31 ergs. Kuznetsov et al (2005), Grechnev et al (2005) and Kurt et al (2010) observed this event with CORONAS-F. Kopp et al (2005) detected this flare with the Total Irradiance Monitor. Gros et al (2004) and Kiener et al (2006) investigated gamma radiation of this flare by the gamma-ray spectrometer SPI/INTEGRAL.…”

Section: Introductionmentioning

confidence: 93%

New estimation of non-thermal electron energetics in the giant solar flare on 28 October 2003 based on Mars Odyssey observations

Nizamov

Zimovets

Golovin

et al. 2018

Journal of Atmospheric and Solar-Terrestrial Physics

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A new estimation of the total number and energy of the non-thermal electrons produced in the giant (> X17) solar flare on 2003 October 28 is presented based on the analysis of the observations of the hard X-ray (HXR) emission by the High Energy Neutron Detector (HEND) onboard the Mars Odyssey spacecraft orbiting Mars. Previous estimations of the non-thermal electron energy based on the Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) data were incomplete since RHESSI missed the peak of the flare impulsive phase. In contrast, HEND observed the whole flare. We used two models to estimate the energy of the non-thermal electrons: the cold thick target model and the warm thick target model. More specifically, in the second case we employed an approximation which relates the pitch-angle averaged injection spectrum with the electron spectrum integrated over the emitting source. We found that, depending on the model used and the lowenergy cutoff (E c ) of the non-thermal electrons, the estimate of their total energy in the entire flare can vary from 2.3 × 10 32 to 6.2 × 10 33 ergs. The lowest estimate, 2.3 × 10 32 ergs, obtained within the cold thick target model * Corresponding author Email address: nizamov@physics.msu.ru (B.A. Nizamov) and fixed E c = 43 keV, is consistent with the previous estimate. In this case, non-thermal electrons accelerated in the peak of the flare impulsive phase missed by RHESSI contained approximately 40% of the total energy of non-thermal electrons of the entire flare. The highest value, 6.2 × 10 33 ergs, obtained with the cold thick target model and fixed E c = 10 keV, looks abnormally high, since it exceeds the total non-potential magnetic energy of the parent active region and the total bolometric energy radiated in the flare.Our estimates also show that the total number and energetics of the HXRproducing electrons in the flare region is a few orders of magnitude higher than of the population of energetic electrons injected into interplanetary space.

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“…They almost always occur with a fast halo CME. Such flares have also been studied before, in particular with the spacecraft (SC) CORONAS-F/SONG [Kurt et al, 2010] and GAMMA/GAMMA1 [Akimov et al, 1991], but little attention has been paid to the role of CME in accelerating protons to high energies. Only individual events in terms of CME have been analyzed in detail [Grechnev et al, 2008].…”

Section: Introductionmentioning

confidence: 99%

Features of development of sustained fluxes of high-energy gamma-ray emission at different stages of solar flares

Minasiants¹,

Minasyants

Minasiants³

et al. 2019

Solar-Terrestrial Physics

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We have studied properties of sustained gamma fluxes having quantum energies of >100 MeV at different stages of flares with 1-min temporal resolution (Fermi/LAT). The most probable process of emergence of high-energy gamma-quanta during the impulsive phase of flares (6 events) has been confirmed. Acceleration of particles, produced by flare energy release (at dissipation of current sheet), occurs when they interact with a shock front of a coronal mass ejection (CME), which develops in the same active region at the same time. Nuclear interactions of accelerated protons (>500 MeV) with plasma ions lead further to the emergence of high-energy gamma-quanta. We have established that the interaction between a flare flux and a high-speed CME during the flare impulsive phase occurs within fairly limited periods — from 2 to 16 min. In the events considered, we have found a direct connection between maximum gamma flux F max (γ > 100 MeV) and CME velocity. High maximum values of gamma fluxes are typical of the flare impulsive phase: 3.5·10⁻⁴ cm⁻²s⁻¹ ≤ F max (γ > 100 MeV) ≤ 1.3·10⁻² cm⁻² s⁻¹. At the same time, the value F max (γ > 100 MeV) = 0.013 cm⁻²s⁻¹ was the highest for the events observed by Fermi/LAT from 2008 to 2017. During the development of CMEs moving with a supersonic speed, shock waves are formed which are the major power source of accelerated particles during the main phase of gradual flares. In some cases, however, the impact of shock waves on particle acceleration is the greatest in the short impulsive phase. To reveal parameters most effectively influencing the generation of high-energy gamma-ray emission, we have compared 17 flare events. The most significant parameter proved to be the time interval of joint action of flare process and CME shocks. We have established that during simultaneous development of flare process and CME attendant on the flare, the most efficient particle acceleration occurs which gives rise to maximum fluxes of high-energy gamma-quanta.

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High-energy gamma radiation of solar flares as an indicator of acceleration of energetic protons

Cited by 24 publications

References 20 publications

Solar Cosmic Rays

Solar Cosmic Rays

New estimation of non-thermal electron energetics in the giant solar flare on 28 October 2003 based on Mars Odyssey observations

Features of development of sustained fluxes of high-energy gamma-ray emission at different stages of solar flares

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