<i>RHESSI</i>
                    OBSERVATIONS OF THE PROPORTIONAL ACCELERATION OF RELATIVISTIC &gt;0.3 MeV ELECTRONS AND &gt;30 MeV PROTONS IN SOLAR FLARES

Shih, Albert Y.; Lin, R. P.; Smith, D. M.

doi:10.1088/0004-637x/698/2/l152

Cited by 119 publications

(107 citation statements)

References 42 publications

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“…The dominant radio emission mechanisms are designated by RS (gyrosynchrotron), RF (free-free), and RP (plasma-frequency mechanisms). Gamma rays typically accompany HXR when detectable (e.g., Cliver et al 1994;Shih et al 2009) Matthews et al 2003;Hudson et al 2006;Wang 2009) make it possible to detect much weaker and therefore more numerous events. Hudson et al (2006) report a GOES C1.3 event observed by TRACE, and Jess et al (2008) found a GOES C2.0 event even with ground-based observations.…”

Section: Flare Morphologymentioning

confidence: 99%

Global Properties of Solar Flares

2011

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This article broadly reviews our knowledge of solar flares. There is a particular focus on their global properties, as opposed to the microphysics such as that needed for magnetic reconnection or particle acceleration as such. Indeed solar flares will always remain in the domain of remote sensing, so we cannot observe the microscales directly and must understand the basic physics entirely via the global properties plus theoretical inference. The global observables include the general energetics-radiation in flares and mass loss in coronal mass ejections (CMEs)-and the formation of different kinds of ejection and global wave disturbance: the type II radio-burst exciter, the Moreton wave, the EIT "wave", and the "sunquake" acoustic waves in the solar interior. Flare radiation and CME kinetic energy can have comparable magnitudes, of order 10 32 erg each for an X-class event, with the bulk of the radiant energy in the visible-UV continuum. We argue that the impulsive phase of the flare dominates the energetics of all of these manifestations, and also point out that energy and momentum in this phase largely reside in the electromagnetic field, not in the observable plasma.

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Section: Flare Morphologymentioning

confidence: 99%

Global Properties of Solar Flares

2011

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“…The relative importance of electron and ion acceleration can also be addressed by comparing the production of ions and quasi-relativistic electrons (more than 300 keV) in flares. Such an analysis has been performed using both SMM/GRS [55,56] and RHESSI [53] observations. Good correlations are found (figure 10b) between the neutron-capture line fluence (taken as representative of the total energy content in protons above 30 MeV) and the bremsstrahlung fluence above 300 keV (taken as representative of the total energy content in electrons above 300 keV).…”

Section: (C) Do All Flares Accelerate Ions?mentioning

confidence: 99%

Solar flares and energetic particles

Vilmer

2012

Phil. Trans. R. Soc. A.

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Solar flares are now observed at all wavelengths from g-rays to decametre radio waves. They are commonly associated with efficient production of energetic particles at all energies. These particles play a major role in the active Sun because they contain a large amount of the energy released during flares. Energetic electrons and ions interact with the solar atmosphere and produce high-energy X-rays and g-rays. Energetic particles can also escape to the corona and interplanetary medium, produce radio emissions (electrons) and may eventually reach the Earth's orbit. I shall review here the available information on energetic particles provided by X-ray/g-ray observations, with particular emphasis on the results obtained recently by the mission Reuven Ramaty High-Energy Solar Spectroscopic Imager. I shall also illustrate how radio observations contribute to our understanding of the electron acceleration sites and to our knowledge on the origin and propagation of energetic particles in the interplanetary medium. I shall finally briefly review some recent progress in the theories of particle acceleration in solar flares and comment on the still challenging issue of connecting particle acceleration processes to the topology of the complex magnetic structures present in the corona.

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“…The two dashed vertical lines indicate the time interval considered to compute the counts recorded by ACS for this flare to be compared with RHESSI data. Such selection has been made in order to match the time interval considered by Shih et al (2009) (see section 4.2). According to these authors, the two peaks occurring before the selected interval are solar emission that did not extend high enough in energy to be included in the integration time.…”

Section: Observing Solar Flares With Integralmentioning

confidence: 99%

Section: Checking the Model Using Rhessi Observationsmentioning

confidence: 99%

“…Shih et al (2009) The number of counts recorded by ACS includes also the contribution from the nuclear γ-ray line emission. In the simulations, this contribution is estimated by taking the value of the non-corrected (of Compton-scattering by the overlying Shih et al (2009) and adding the 2.2-MeV line to the bremsstrahlung spectrum, which we assumed to be an unbroken power law from 50 keV to 8.5 MeV. Then, we take a template of a nuclear γ-ray line emission spectrum and we normalize it such that F (nuclear) = 1.1 × F (2.2 MeV); this value has been found for the June 12, 2010 solar flare observed by Fermi/GBM (Ackermann et al, 2012).…”

Section: Checking the Model Using Rhessi Observationsmentioning

confidence: 99%

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Exploring the Capabilities of the Anti-Coincidence Shield of the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) Spectrometer to Study Solar Flares

et al. 2013

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INTEGRAL is a hard X-ray/γ-ray observatory for astrophysics (ESA) covering photon energies from 15 keV to 10 MeV. It was launched in 2002 and since then the BGO detectors of the Anti-Coincidence shield (ACS) of the SPI spectrometer have detected many hard X-ray (HXR) bursts from the Sun, producing lightcurves at photon energies above ∼100 keV. The spacecraft has a highly elliptical orbit, providing a long uninterrupted observing time (about 90% of the orbital period) with nearly constant background due to the reduction of the crossing time of the Earth's radiation belts. However, due to technical constraints, INTEGRAL cannot point to the Sun and high-energy solar photons are always detected in non-standard observation conditions. To make the data useful for solar studies, we have undertaken a major effort to specify the observing conditions through Monte-Carlo simulations of the response of ACS for several selected flares. We check the performance of the model employed for the Monte-Carlo simulations using RHESSI observations for the same sample of solar flares. We conclude that, despite the fact that INTEGRAL was not designed to perform solar observations, ACS is a useful instrument in solar flare research. In particular, its relatively large effective area allows the determination of good-quality HXR/γ-ray lightcurves for X-and M-class solar flares and, in some cases, probably also for C-class flares.

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RHESSI OBSERVATIONS OF THE PROPORTIONAL ACCELERATION OF RELATIVISTIC >0.3 MeV ELECTRONS AND >30 MeV PROTONS IN SOLAR FLARES

Cited by 119 publications

References 42 publications

Global Properties of Solar Flares

Global Properties of Solar Flares

Solar flares and energetic particles

Exploring the Capabilities of the Anti-Coincidence Shield of the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) Spectrometer to Study Solar Flares

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