Multi-line two-dimensional spectroscopy of a limb flare
Abstract
We present the result of a preliminary analysis of the 2D spectra of Hα and Ca ii lambda 8542 for a limb flare on 11 November, 1998. Near the top of the flaring loop, the Hα line is extraordinarily broadened. The effect of line opacity (or the saturation of line core) cannot fully account for the observed line width since it requires an extremely high loop density (n_H>~ 10(13) cm(-3) when T=10(4) K). The remaining possibility is the broadening by micro-turbulence or inhomogeneous mass motions. Since the two lines demonstrate different broadening effects, it is quite possible that they are formed in different fine structures which cannot be spatially resolved by observations.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- August 1999
- Bibcode:
- 1999A&A...348L..29D
- Keywords:
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- LINE: PROFILES;
- SUN: FLARES;
- SUN: PROMINENCES