Flare loops: observed properties

1991 ◽  
pp. 166-260
Keyword(s):  
1994 ◽  
Vol 144 ◽  
pp. 275-277
Author(s):  
M. Karlický ◽  
J. C. Hénoux

AbstractUsing a new ID hybrid model of the electron bombardment in flare loops, we study not only the evolution of densities, plasma velocities and temperatures in the loop, but also the temporal and spatial evolution of hard X-ray emission. In the present paper a continuous bombardment by electrons isotropically accelerated at the top of flare loop with a power-law injection distribution function is considered. The computations include the effects of the return-current that reduces significantly the depth of the chromospheric layer which is evaporated. The present modelling is made with superthermal electron parameters corresponding to the classical resistivity regime for an input energy flux of superthermal electrons of 109erg cm−2s−1. It was found that due to the electron bombardment the two chromospheric evaporation waves are generated at both feet of the loop and they propagate up to the top, where they collide and cause temporary density and hard X-ray enhancements.


1979 ◽  
Vol 44 ◽  
pp. 357-372
Author(s):  
Z. Švestka

The following subjects were discussed:(1)Filament activation(2)Post-flare loops.(3)Surges and sprays.(4)Coronal transients.(5)Disk vs. limb observations.(6)Solar cycle variations of prominence occurrence.(7)Active prominences patrol service.Of all these items, (1) and (2) were discussed in most detail and we also pay most attention to them in this report. Items (3) and (4) did not bring anything new when compared with the earlier invited presentations given by RUST and ZIRIN and therefore, we omit them.


Solar Physics ◽  
2008 ◽  
Vol 253 (1-2) ◽  
pp. 161-172 ◽  
Author(s):  
Y. T. Tsap ◽  
Y. G. Kopylova ◽  
A. V. Stepanov ◽  
V. F. Melnikov ◽  
K. Shibasaki

Solar Physics ◽  
1996 ◽  
Vol 165 (2) ◽  
pp. 303-328 ◽  
Author(s):  
B. Schmieder ◽  
P. Heinzel ◽  
L. Van Driel-Gesztelyi ◽  
J. R. Lemen
Keyword(s):  

Author(s):  
L. Driel-Gesztelyi ◽  
J. E. Wiik ◽  
B. Schmieder
Keyword(s):  

2001 ◽  
Vol 203 ◽  
pp. 264-266
Author(s):  
I. E. Dammasch ◽  
W. Curdt ◽  
B. Kliem ◽  
B. N. Dwivedi ◽  
K. Wilhelm

We report on EUV observations of a solar limb flare obtained by the SUMER spectrometer. A time series was taken with fixed slit position and several spectral windows that covered a wide temperature range (104-107 K), preceded and followed by contextual raster scans in a He I line. During the time series, a C4.6 flare occurred in the region, also imaged in the EUV by SOHO/EIT and in soft X rays by YOHKOH/SXT. The temporal evolution seen in the SUMER spectra reveals a close spatial relationship and a correlated dynamical behaviour of the hot (T ≈ 107 K) and cool (T ≈ 104 K) material, which are difficult to reconcile with the notion (based on the Kopp-Pneuman flare model) that cool loops form at a lower height than the hot flare loops.


2011 ◽  
Vol 742 (2) ◽  
pp. 92 ◽  
Author(s):  
Harry P. Warren ◽  
Casey M. O’Brien ◽  
Neil R. Sheeley
Keyword(s):  

1997 ◽  
Vol 163 ◽  
pp. 717-718
Author(s):  
Mitsuru Hayashi ◽  
Kazunari Shibata ◽  
Ryoji Matsumoto

AbstractHere we present a model of hard X-ray flares and hot plasma outflows (optical jets) observed in protostars. Assuming that the dipole magnetic field of a protostar threads the protostellar disk, we carried out 2.5-dimensional magnetohydrodynamic (MHD) simulations of the diskstar interaction. The closed magnetic loops connecting the central star and the disk are twisted by the rotation of the disk. In the presence of resistivity, magnetic reconnection takes place in the current sheet formed inside the expanding loops. Hot, outgoing plasmoid and post flare loops are formed as a result of the reconnection. Numerical results are consistent with the observed plasma temperature (107 – 108K), the length of the flaring loop (1011 – 1012cm), and the speed of optical jets (200 – 400 km s−1 ).


Solar Physics ◽  
1995 ◽  
Vol 159 (2) ◽  
pp. 275-299 ◽  
Author(s):  
J. Lin ◽  
T. G. Forbes ◽  
E. R. Priest ◽  
T. N. Bungey
Keyword(s):  

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