RHESSI observations of the size scales of solar hard X-ray sources

被引：23

作者：

Schmahl, EJ ^{[1
]}

Hurford, GJ

机构：

[1] Univ Maryland, Dept Astron, College Pk, MD 20742 USA

[2] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA

来源：

SOLAR PHYSICS | 2002年 / 210卷 / 1-2期

基金：

美国国家航空航天局;

关键词：

Relative Amplitude; Grid Transmission; RHESSI Observation; Modulation Amplitude Function; Angular Pitch;

D O I：

10.1023/A:1022484822851

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

The Reuven Ramaty High-Energy Solar Spectroscopic Imager RHESSI telescope produces hard X-ray images by Fourier imaging techniques that are capable of determining the sizes and shapes of sources with spatial scales in the range similar to 2" - 180". Applying the method of Unpixelized Forward Fitting to RHESSI modulation profiles from simple flares, we have identified the presence of 'halo' sources whose size scale (similar to 40") greatly exceeds the 'core' sizes (less than or equal to6" - 14"). Although such 'core-halo' structures have been observed at radio wavelengths using a similar technique, the radio and hard X-ray phenomena may be different. These observations raise questions about the nature of these 'halos'. Among the possibilities are that they are albedo sources, thin-target loops, or unidentified diffuse structures.

引用

页码：273 / 286

页数：14