A STUDY OF SOLAR-FLARE ENERGY-TRANSPORT BASED ON COORDINATED H-ALPHA AND X-RAY OBSERVATIONS

被引:15
作者
CANFIELD, RC
ZARRO, DM
WULSER, JP
DENNIS, BR
机构
[1] NASA,GODDARD SPACE FLIGHT CTR,APPL RES CORP,GREENBELT,MD 20771
[2] NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771
[3] APPL RES CORP,LANDOVER,MD 20785
[4] LOCKHEED PALO ALTO RES LABS,PALO ALTO,CA 94304
关键词
LINE PROFILES; SUN; CHROMOSPHERE; CORONA; FLARES; X-RAYS;
D O I
10.1086/169663
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Coordinated H-alpha, hard X-ray (HXR), and soft X-ray observations of five solar flares allow us to determine, for the first time, the temporal variation of the ratio of H-alpha to nonthermal hard X-ray emissions, and to compare its behavior to the predictions of a hydrostatic one-dimensional thick-target nonthermal electron model of solar flare energy transport. We have used the observations to estimate the emitted flare energy flux F(H)-alpha in H-alpha, the flux of energy F-20 deposited by nonthermal electrons with energies above 20 keV, and the pressure p(c) of soft X-ray emitting plasma as functions of time during the impulsive phase of each flare. The F(H)-alpha/F-20 ratio show a power-law dependence on F-20 of the form F(H)-alpha/F-20 proportional F-20-(0.7 +/- 0.1). Analyzing the observations with the thick-target model, we demonstrate that: (1) the power-law dependence of the F(H)-alpha/F-20 ratio on F-20 is consistent with that predicted by the model if the nonthermal electron precipitation area does not vary by more than a factor of five during the impulsive phase of the observed flares; (2) there is evidence for modification of the power-law dependence by hydrostatic pressure effects; (3) the observed magnitude of the F(H)-alpha/F-20 ratio implies a small precipitation area of approximately 10(17) cm2 and correspondingly large beam fluxes (approximately 10(12) ergs cm-2 s-1 for all five flares.
引用
收藏
页码:671 / 676
页数:6
相关论文
共 25 条
[1]   SOFT-X-RAY POLYCHROMATOR FOR THE SOLAR MAXIMUM MISSION [J].
ACTON, LW ;
CULHANE, JL ;
GABRIEL, AH ;
BENTLEY, RD ;
BOWLES, JA ;
FIRTH, JG ;
FINCH, ML ;
GILBRETH, CW ;
GUTTRIDGE, P ;
HAYES, RW ;
JOKI, EG ;
JONES, BB ;
KENT, BJ ;
LEIBACHER, JW ;
NOBLES, RA ;
PATRICK, TJ ;
PHILLIPS, KJH ;
RAPLEY, CG ;
SHEATHER, PH ;
SHERMAN, JC ;
STARK, JP ;
SPRINGER, LA ;
TURNER, RF ;
WOLFSON, CJ .
SOLAR PHYSICS, 1980, 65 (01) :53-71
[2]   DIELECTRONIC SATELLITE SPECTRA FOR HIGHLY-CHARGED HELIUM-LIKE IONS .7. CALCIUM SPECTRA THEORY AND COMPARISON WITH SMM OBSERVATIONS [J].
BELYDUBAU, F ;
DUBAU, J ;
FAUCHER, P ;
GABRIEL, AH ;
LOULERGUE, M ;
STEENMANCLARK, L ;
VOLONTE, S ;
ANTONUCCI, E ;
RAPLEY, CG .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1982, 201 (03) :1155-1169
[4]   COLLECTIVE PLASMA EFFECTS AND ELECTRON NUMBER PROBLEM IN SOLAR HARD X-RAY BURSTS [J].
BROWN, JC ;
MELROSE, DB .
SOLAR PHYSICS, 1977, 52 (01) :117-131
[5]   IMPULSIVE H-ALPHA DIAGNOSTICS OF ELECTRON-BEAM-HEATED SOLAR-FLARE MODEL CHROMOSPHERES [J].
CANFIELD, RC ;
GAYLEY, KG .
ASTROPHYSICAL JOURNAL, 1987, 322 (02) :999-1009
[6]   THE H-ALPHA SPECTRAL COUNTERPARTS OF SOLAR HARD X-RAY MICROFLARES [J].
CANFIELD, RC ;
METCALF, TR .
ASTROPHYSICAL JOURNAL, 1987, 321 (01) :586-592
[7]   THE H-ALPHA SPECTRAL SIGNATURES OF SOLAR-FLARE NONTHERMAL ELECTRONS, CONDUCTIVE FLUX, AND CORONAL PRESSURE [J].
CANFIELD, RC ;
GUNKLER, TA ;
RICCHIAZZI, PJ .
ASTROPHYSICAL JOURNAL, 1984, 282 (01) :296-307
[8]   MOMENTUM BALANCE IN 4 SOLAR-FLARES [J].
CANFIELD, RC ;
ZARRO, DM ;
METCALF, TR ;
LEMEN, JR .
ASTROPHYSICAL JOURNAL, 1990, 348 (01) :333-&
[9]   IMPULSIVE EXTREME-ULTRAVIOLET AND HARD X-RAY-EMISSION DURING SOLAR-FLARES [J].
DONNELLY, RF ;
KANE, SR .
ASTROPHYSICAL JOURNAL, 1978, 222 (03) :1043-1053
[10]   EFFECT OF REVERSE CURRENTS ON THE DYNAMICS OF NONTHERMAL ELECTRON-BEAMS IN SOLAR-FLARES AND ON THEIR EMITTED X-RAY BREMSSTRAHLUNG [J].
EMSLIE, AG .
ASTROPHYSICAL JOURNAL, 1980, 235 (03) :1055-1065