ON THE DEPENDENCE OF SOLAR-FLARE X-RAY SPECTRAL-LINE INTENSITY RATIOS OF HIGHLY IONIZED SULFUR, CALCIUM, AND IRON ON ELECTRON-TEMPERATURE, DIFFERENTIAL EMISSION MEASURE, AND ATOMIC PHYSICS

被引:17
作者
DOSCHEK, GA
FLUDRA, A
BENTLEY, RD
LANG, J
PHILLIPS, KJH
WATANABE, T
机构
[1] UCL, MULLARD SPACE SCI LAB, DORKING RH5 6NT, SURREY, ENGLAND
[2] RUTHERFORD APPLETON LAB, DIV ASTROPHYS, DIDCOT OX11 0QX, OXON, ENGLAND
[3] NATL ASTRON OBSERV, TOKYO 181, JAPAN
关键词
Sun: flares; Sun: X-rays; X-rays: spectra;
D O I
10.1086/169019
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We derive values from solar flare spectra for the X-ray spectral line intensity ratio, w(Ca XIX)/w(Fe XXV), as a function of the temperature deduced from the dielectronic X-ray line j of Fe XXIV and the resonance line w of Fe XXV. The lines w and j represent the transition, Is2 1S0-1s2p 1P1 and Is22p 2P3/2-1s2p2 2D5/2, respectively. This intensity ratio is determined from a number of solar flares observed by X-ray Bragg crystal spectrometers flown on the P78-1 spacecraft and on the Solar Maximum Mission spacecraft. We also derive the relationship between the temperature determined from calcium X-ray lines and the temperature determined from iron X-ray lines for the same set of data. We compare these data with theoretical w(Ca XIX)/w(Fe XXV) ratios determined from parametric models of the differential emission measure, that are constrained by the calcium and iron temperatures. The model calculations show the effect of varying differential emission measure on the w(Ca XIX)/w(Fe XXV) ratio and allow us to determine which of three different published ionization equilibrium calculations for iron and calcium best fit the data. The functional relationship of w(Ca XIX)/ w(Fe XXV) with temperature and the relationship of the calcium and iron temperatures, determined from the data, also provide a method for estimating the approximate temperatures at which iron and calcium are formed in flares when dielectronic line ratios cannot be used. However, the method is not nearly as precise as the dielectronic technique. The model calculations are also used to predict functional relationships between spectral lines for flare X-ray lines of S XV and Fe XXVI.
引用
收藏
页码:665 / 673
页数:9
相关论文
共 32 条
[21]   DIELECTRONIC SATELLITE SPECTRA FOR HIGHLY CHARGED HELIUM-LIKE IONS .4. IRON SATELLITE LINES AS A MEASURE OF NONTHERMAL ELECTRON-ENERGY DISTRIBUTIONS [J].
GABRIEL, AH ;
PHILLIPS, KJH .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1979, 189 (02) :319-327
[22]  
Jakimiec J., 1988, ADV SPACE RES, V8, P231
[23]  
LEMEN JR, 1984, ASTRON ASTROPHYS, V135, P313
[24]   THE SOLAR-A MISSION [J].
OGAWARA, Y .
SOLAR PHYSICS, 1987, 113 (1-2) :361-370
[25]   IMPROVED EXCITATION RATE COEFFICIENTS FOR THE N=2 AND N=3 LEVELS OF CA XIX AND FE-XXV INCLUDING FINE-STRUCTURE [J].
PRADHAN, AK .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1985, 59 (02) :183-195
[26]   OBSERVATION OF NONTHERMAL ENERGY-DISTRIBUTIONS DURING THE IMPULSIVE PHASE OF SOLAR-FLARES [J].
SEELY, JF ;
FELDMAN, U ;
DOSCHEK, GA .
ASTROPHYSICAL JOURNAL, 1987, 319 (01) :541-554
[27]   TIME VARIATIONS OF THE CALCIUM ELEMENTAL ABUNDANCE IN FLARES FROM NOAA ACTIVE REGION-2562 AND REGION-2779 [J].
SYLWESTER, J ;
ZOLCINSKICOUET, MC ;
BENTLEY, RD ;
LEMEN, JR .
JOURNAL DE PHYSIQUE, 1988, 49 (C-1) :189-193
[28]   VARIATION IN OBSERVED CORONAL CALCIUM ABUNDANCE OF X-RAY FLARE PLASMAS [J].
SYLWESTER, J ;
LEMEN, JR ;
MEWE, R .
NATURE, 1984, 310 (5979) :665-666
[29]  
TANAKA K, 1987, PUBL ASTRON SOC JPN, V39, P1
[30]   HIGH-RESOLUTION SOLAR-FLARE X-RAY-SPECTRA OBTAINED WITH ROTATING SPECTROMETERS ON THE HINOTORI SATELLITE [J].
TANAKA, K ;
WATANABE, T ;
NISHI, K ;
AKITA, K .
ASTROPHYSICAL JOURNAL, 1982, 254 (02) :L59-L63