Chromospheric magnetic reconnection and its implication for coronal heating

被引:25
作者
Sturrock, PA
Roald, CB
Wolfson, R
机构
[1] Stanford Univ, Ctr Space Sci & Astrophys, Stanford, CA 94305 USA
[2] Middlebury Coll, Dept Phys, Middlebury, VT 05753 USA
基金
美国国家航空航天局;
关键词
Sun : corona; Sun : magnetic fields; Sun; X-rays; gamma rays;
D O I
10.1086/312301
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
According to recent data analyses, the relationship between the coronal-energy flux density and the photospheric magnetic flux density is approximately power law; estimates of the exponent tend to be noninteger and fall in the range 1-2. The Index is closer red 2 or quiet regions and loser to 1 for active regions. We here examine this relationship on the basis of a recent model of coronal heating. We assume that the coronal energy flux is derived from reconnection of neighboring flux tubes at the level of the chromosphere and we examine the rate at which such reconnection would occur in terms of a simple kinetic-theory model bn this model flux elements appear randomly within supergranulation cells, are carried into the network according to a prescribed velocity held and cancel in;the network due to "collisions" between elements of opposite polarity. For any limited range of magnetic flux density, the relationship is;approximately power law. We find ;that the power-law index Is in the range 1-2: for weal fields it is close to 2, and for strong fields a is close to 1, in agreement with available evidence.
引用
收藏
页码:L75 / L78
页数:4
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