High time resolution observations of H alpha line profiles during the impulsive phase of a solar flare

Abstract

view Abstract Citations (75) References (12) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS High Time Resolution Observations of H alpha Line Profiles during the Impulsive Phase of a Solar Flare Wuelser, Jean-Pierre ; Marti, Hans 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 full text sources ADS |