Does the region of flare-energy release work as a vacuum-cleaner?

2013 ◽  
Vol 350 (1) ◽  
pp. 11-19 ◽  
Author(s):  
A. Solov’ev ◽  
K. Murawski
Keyword(s):  
Energy Release ◽  
Vacuum Cleaner ◽  
Flare Energy

scholarly journals Gamma-rays from Solar Flares

2000 ◽  
Vol 195 ◽  
pp. 123-132 ◽  
Author(s):  
R. Ramaty ◽  
N. Mandzhavidze
Keyword(s):  
Energy Release ◽  
Gamma Rays ◽  
Solar Flares ◽  
Gamma Ray ◽  
Particle Interaction ◽  
Mass Motion ◽  
Relativistic Electrons ◽  
Total Energy Release ◽  
Flare Energy ◽  
Accelerated Particles

Gamma-ray emission is the most direct diagnostic of energetic ions and relativistic electrons in solar flares. Analysis of solar flare gamma-ray data has shown: (i) ion acceleration is a major consequence of flare energy release, as the total flare energy in accelerated particles appears to be equipartitioned between ≳ 1 MeV/nucleon ions and ≳ 20 keV electrons, and amounts to an important fraction of the total energy release; (ii) there are flares for which over 50% of the energy is in a particles and heavier ions; (iii) in both impulsive and gradual flares, the particles that interact at the Sun and produce gamma rays are essentially always accelerated by the same mechanism that operates in impulsive flares, probably stochastic acceleration through gyroresonant wave particle interaction; and (iv) gamma-ray spectroscopy can provide new information on solar abundances, for example the site of the FIP-bias onset and the photospheric 3He abundance. We propose a new technique for the investigation of mass motion and mixing in the solar atmosphere: the observations of gamma-ray lines from long-term radioactivity produced by flare accelerated particles.

The observed characteristics of flare energy release. I - Magnetic structure at the energy release site

1988 ◽  
Vol 326 ◽  
pp. 425 ◽  
Author(s):  
Marcos E. Machado ◽  
Ronald L. Moore ◽  
Ana M. Hernandez ◽  
Marta G. Rovira ◽  
Mona J. Hagyard ◽  
...  
Keyword(s):  
Energy Release ◽  
Magnetic Structure ◽  
Release Site ◽  
Flare Energy

scholarly journals Hard X-ray Spectrum of the Above-the-Looptop Source in Impulsive Solar Flares

2000 ◽  
Vol 195 ◽  
pp. 413-414
Author(s):  
S. Masuda
Keyword(s):  
Magnetic Reconnection ◽  
Energy Release ◽  
Solar Flares ◽  
Count Rate ◽  
High Quality ◽  
X Ray ◽  
Flare Energy

Extended AbstractThe Hard X-ray Telescope (HXT: Kosugi et al. 1991) onboard Yohkoh has observed that, in impulsive solar flares, a hard X-ray source is located above the apex of a soft X-ray flaring loop, in addition to double footpoint sources (Masuda et al. 1994, 1995). This observation suggests that flare energy-release, probably magnetic reconnection, takes place not in the soft X-ray loop but above the loop. It is important to derive the hard X-ray spectrum of the above-the-looptop source accurately in order to understand how electrons are energized there. The above-the-looptop source was most clearly observed during the 13 January 1992 flare. However, the count rate, especially in the H-band (53–93 keV), is too small to synthesize high-quality images and to derive an accurate spectrum.

Yohkoh Reveals Site of Solar Flare Energy Release

Physics Today ◽  
1995 ◽  
Vol 48 (1) ◽  
pp. 18-18 ◽  
Author(s):  
Stephen G. Benka
Keyword(s):  
Solar Flare ◽  
Energy Release ◽  
Flare Energy

scholarly journals Study of Flare Energy Release Using Events with Numerous Type III-like Bursts in Microwaves

Solar Physics ◽  
2012 ◽  
Vol 280 (2) ◽  
pp. 537-549 ◽  
Author(s):  
N. S. Meshalkina ◽  
A. T. Altyntsev ◽  
D. A. Zhdanov ◽  
S. V. Lesovoi ◽  
A. A. Kochanov ◽  
...  
Keyword(s):  
Energy Release ◽  
Type Iii ◽  
Flare Energy ◽  
Numerous Type

scholarly journals Post-Eruptive Flare Energy Release as Detected on AU Mic by EUVE

1996 ◽  
Vol 152 ◽  
pp. 175-180
Author(s):  
M.M. Katsova ◽  
J.J. Drake ◽  
M.A. Livshits
Keyword(s):  
Energy Release ◽  
Extreme Ultraviolet ◽  
Emission Measure ◽  
Coronal Loops ◽  
X Rays ◽  
Stellar Radius ◽  
Flare Energy ◽  
Long Duration ◽  
Deep Survey ◽  
Region Scale

The long-duration emission arising after the impulsive rise and decay in a flaring event observed by the Extreme Ultraviolet Explorer on the red dwarf star AU Mic is discussed. The decay of the intensity in the Deep Survey 65–190 Å band and in the Fe XVIII line during this prolonged event is 10 times slower than the time of radiative cooling of coronal loops with the typical for the flare plasma density. The temporal behavior of the emission measure is determined for both the 65–190 Å band and the Fe XVIII line fluxes. The total energy emitted in the 1–2000 Å region over nearly 12 hrs is 3 · 1035 ergs. We first point out some difficulties with earlier explanations proposed for this event; we then propose the following physical model: the source of the prolonged emission is a system of high coronal loops, the size of which is more than the active region scale, but less than the stellar radius. Such systems are observed in soft X-rays during large solar flares after coronal mass ejections. Some additional post-flare energy input into this high coronal loop system can be caused by reconnection in a vertical current sheet, and this post-eruptive energy release provides prolonged and intensive EUV emission.Apparently, we are faced here with new kind of the surface activity on late-type stars which is intermediate between impulsive flares on red dwarfs and long-duration, powerful events the subgiants components of the RS CVn binaries.

Flare energy release: observational consequences and signatures

1991 ◽  
Vol 336 (1643) ◽  
pp. 381-388 ◽  
Keyword(s):  
Particle Acceleration ◽  
Spatial Distribution ◽  
Energy Release ◽  
Energetic Electron ◽  
Spatial Relation ◽  
Solar Observatory ◽  
Electron Precipitation ◽  
Mass Motion ◽  
Thermal Electron ◽  
Flare Energy

It is generally accepted, but not yet compellingly demonstrated, that the energy released in solar flares is stored in stressed magnetic fields. Little is known, at present, about how the most obvious manifestations of flare energy release — heating, mass motion, magnetic field reconfiguration and particle acceleration — are related to the spatial distribution of free energy within those fields. To address this issue we have underway at Mees Solar Observatory a programme of simultaneous polarimetric and spectroscopic observations that allow us to explore the spatial relation between active region currents, flare particle acceleration and flare heating. In this paper we discuss several days observations of two flare-productive active regions. By using the Haleakala Stokes polarimeter, we observed the spatial distribution of the Stokes profiles of two photospheric Fe 1 lines, from which we inferred the spatial distribution of the vector m agnetic field and the vertical current density. In flares that were observed on the same days, we then compared the locations of vertical currents to the sites of non-thermal electron precipitation and high coronal pressure inferred from Hα line profiles and spectroheliograms obtained with the Mees charge coupled device imaging spectrograph. Without exception we found that the sites of significant energetic electron precipitation into the chromosphere were at the edges of regions of vertical current, not within them. In contrast, we found that the footpoints of high-pressure flare plasmas during the main phase of the observed flares all coincided very well with such currents.

Sign in / Sign up

Export Citation Format

Share Document