High Time Resolution Observations of H alpha Line Profiles during the Impulsive Phase of a Solar Flare
Abstract
H-alpha observations of the impulsive phase of a 1B/M1 solar flare on May 24, 1987, were carried out with high temporal resolution. A line center imaging system and an imaging spectrograph for line profile acquisition have been operated simultaneously with 0.3 s and 2.3 s temporal resolution, respectively. The temporal evolution at line center and in the blue and red wing have been correlated with hard X-ray data from HXRBS. The observed line profiles have been analyzed in terms of dynamic H-alpha line profile calculations by Canfield and Gayley. The combined H-alpha and hard X-ray signatures of two flare kernels are compatible with the theoretical predictions for strong nonthermal electron heating and the formation of a downward moving chromospheric condensation. A third kernel also shows the predicted downward moving chromospheric material, but its temporal evolution is not compatible with electron beam heating.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1989
- DOI:
- 10.1086/167567
- Bibcode:
- 1989ApJ...341.1088W
- Keywords:
-
- H Alpha Line;
- Solar Flares;
- Solar Spectra;
- Spectrum Analysis;
- Temporal Resolution;
- Line Spectra;
- Solar X-Rays;
- X Ray Spectra;
- Solar Physics;
- LINE PROFILES;
- SUN: FLARES