Hα profiles from electron-heated solar flares

✍ Scribed by John C. Brown; Richard C. Canfield; Matthew N. Robertson

• Publisher: Springer
• Year: 1978
• Tongue: English
• Weight: 542 KB
• Volume: 57
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00160112

✦ Synopsis

We briefly review the status of models of optical flare heating by electron bombardment. We recompute Brown's (1973a) flare model atmospheres using considerably revised radiative loss rates, based on Canfield's (1974b) method applied to Ha, La, and H-. Profiles of Ha are computed and compared with observation. The computed profiles agree satisfactorily with those observed during the large 1972 August 7 flare, if spatial and velocity inhomogeneities are assumed. The electron injection rate inferred from Ha is one order of magnitude less than that inferred from hard X-rays, for this event. This may be due to either (1) the neglect of a mechanism that reduces the thick-target electron injection rate or (2) failure to incorporate important radiative loss terms.