Extended gamma-ray emission of the solar flares in june 1991

Rank, G.; Ryan, J. M.; Debrunner, H.; McConnell, Mark L.; Schönfelder, V.

doi:10.1051/0004-6361:20011060

Cited by 51 publications

(51 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In general, the extended phases of the flares of 1991 June 11 and 15 were marked by strong similarities of the decay phases of the 2.22 MeV neutron-capture line, the 4Y7 MeV nuclear deexcitation lines, and the 0 -decay emission. While the close matching of the nuclear line and 0 -decay emissions might be challenging in terms of our proposed SEP-SW sources, they are also inconsistent with trapping of SEPs in the solar corona (Rank et al 2001), which requires a gradually hardening spectrum.…”

Section: Temporal Separations Of Flare and Interplanetary -Raysmentioning

confidence: 77%

“…However, no 0 -decay emission was observed during the impulsive phase (Rank et al 2001) of that flare. In general, the extended phases of the flares of 1991 June 11 and 15 were marked by strong similarities of the decay phases of the 2.22 MeV neutron-capture line, the 4Y7 MeV nuclear deexcitation lines, and the 0 -decay emission.…”

Section: Temporal Separations Of Flare and Interplanetary -Raysmentioning

confidence: 91%

See 1 more Smart Citation

Remote Sensing of Gamma‐Ray Emission from Solar Energetic Proton Interactions with the Solar Wind

Kahler¹,

Ragot²

2008

ApJ

View full text Add to dashboard Cite

The properties of solar energetic particles (SEPs) in solar flares are studied through remote imaging in the radio, hard X-ray, and -ray energy ranges. However, the heliospheric SEP populations are observed only in situ by satellite measurements, which drastically limits our understanding of their spatial and temporal variations. Can those SEP populations be remotely imaged, as are the solar SEPs? We consider two possibilities for detecting faint -ray emission from SEP interactions with solar wind (SW) ions. First, the 6.13 and 4.44 MeV -ray lines of 16 O and 12 C, respectively, produced by the interactions of the SEPs from a large low-energy (E < 30 MeV) gradual event are calculated and found to be far below a detectable level. Then the expected 0 -decay -ray emission is calculated for the intense ground-level event (GLE) of 2005 January 20 and compared with (1) the observed Galactic and extragalactic background and (2) the expected near-solar emission from inverse-Compton scattering of solar photons by cosmic-ray electrons and from Galactic cosmic-ray collisions with the solar atmosphere. It appears feasible to detect the 0 -decay emission from that event with a detector of the size of the Large Area Telescope on GLAST. Earlier 1982 and 1991 flare observations of long-duration (hours) 0 -decays were attributed to E > 300 MeV protons captured in strong coronal loops, but we suggest that the observed emission was due to SEP-SW collisions following shock acceleration on open field lines.

show abstract

Section: Temporal Separations Of Flare and Interplanetary -Raysmentioning

confidence: 77%

Section: Temporal Separations Of Flare and Interplanetary -Raysmentioning

confidence: 91%

Remote Sensing of Gamma‐Ray Emission from Solar Energetic Proton Interactions with the Solar Wind

Kahler¹,

Ragot²

2008

ApJ

View full text Add to dashboard Cite

show abstract

“…Alternatively, the particles could have been accelerated in large static loops filled with MHD turbulence (Ryan and Lee 1991), in the electrostatic potential behind the CME in the reconnection sheet (Litvinenko and Somov 1995), or in an episodical acceleration process (van den Oord 1993) with successive episodes of particle acceleration and subsequent trapping for moderately long times (Mandzhavidze et al 1996). For the June 1991 LDGRF, Rank et al (2001) suggest a continuous though evolving acceleration process.…”

Section: Interacting and Escaping Particlesmentioning

confidence: 99%

Current views on impulsive and gradual solar energetic particle events

Kallenrode

2003

J. Phys. G: Nucl. Part. Phys.

131

View full text Add to dashboard Cite

Solar energetic particles (SEPs) are one manifestation of violent energy releases on the Sun. The study of their acceleration and propagation reveals information about basic plasma-physical processes, such as reconnection, shock acceleration and wave-particle interaction, in astrophysical objects, such as stars, magnetospheres or the diluted plasma of the interstellar or interplanetary medium. This paper introduces the current classification scheme for solar energetic particle events, its relation to the underlying acceleration processes, and addresses open questions regarding the better understanding of SEPs as well as the underlying physical processes. Modifications to the current paradigm considering more recent observations will be suggested.

show abstract

“…Smooth light curves of soft X-ray emission tell us that the energy released by each impact of plasma blobs is small compared to the total energy. Shocks and turbulences are favorable conditions for extended high-energy phenomena lasting several hours (Rank et al 2001). Information about the falling mass is not available from the observations.…”

Section: Conclusion and Discussionmentioning

confidence: 99%

Energy and Mass Supply in the Decay Phase of Long-Duration Solar Flare Events

Shibasaki

2002

ApJ

View full text Add to dashboard Cite

A new mechanism is proposed to supply energy and mass in the decay phase of long-duration solar flare events. The long-duration event (LDE) flares are known to be caused by filament eruptions, and bright arcade structures continue for several hours or even a day. To overcome the short cooling time, continuous energy and mass supplies are required. Continuous magnetic reconnection in the current sheet extended above the arcade has been proposed to supply energy and mass. However, no direct observations of the current sheet have been reported. The new mechanism that we are proposing is based on the recent observations of downflows onto the top of arcades along the vertical spiky features observed by the Yohkoh soft X-ray telescope. We interpret these downflows as free-falling plasma. Plasma falling from a high altitude can convert its potential energy into thermal energy and heat itself with an average temperature of several million kelvins. Observations show that the downflows continue for several hours. Coronagraph observations by the Solar and Heliospheric Observatory Large Angle and Spectrometric Coronagraph also show many falling features after coronal mass ejections. Instead of magnetic reconnection, we propose that these falling plasmas are the source of the energy and mass supply for LDEs in the long-lasting decay phase.

show abstract

Extended gamma-ray emission of the solar flares in june 1991

Cited by 51 publications

References 28 publications

Remote Sensing of Gamma‐Ray Emission from Solar Energetic Proton Interactions with the Solar Wind

Remote Sensing of Gamma‐Ray Emission from Solar Energetic Proton Interactions with the Solar Wind

Current views on impulsive and gradual solar energetic particle events

Energy and Mass Supply in the Decay Phase of Long-Duration Solar Flare Events

Contact Info

Product

Resources

About