H. cap alpha. spectral signatures of solar flare nonthermal electrons, conductive flux, and coronal pressure

Journal Article · Sun Jul 01 04:00:00 EDT 1984 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/162203· OSTI ID:6196285

Canfield, R C; Gunkler, T A; Ricchazzi, P J

We have calculated H..cap alpha.. line profiles based primarily on the static moddel flare chromospheres of Ricchizzi and Canfield, which show the effects of enhanced fluxes of nonthermal electrons and heat, as well as enhanced pressure, on the temperature, density, and ionization structure of the chromosphere. Both hydrostatic and impulsive phase models are examined. Hydrostatic model atmospheres with substantial electron heating characteristically produce wide and bright H..cap alpha.. profiles with a central reversal (measured by the ratio of central to peak intensity) that is insensitive to the electron heating rate. In the impulsive atmospheres, however, the central reversal does depend, to some degree, on the nonthermal electron heating rate. Enhabced thermal conduction reduces the width and total intensity of the profiles. High thermal conduction alone cannot account for flare H..cap alpha.. enhancements. High coronal pressure dramatically increases the width and total intensity of the H..cap alpha.. profiles, while reducing the central reversal.

• Research Organization: Center for Astrophysics and Space Sciences, University of California, San Diego
• OSTI ID: 6196285
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 282:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
ATOMIC MODELS
BALMER LINES
CHROMOSPHERE
ELECTRONS
ELEMENTARY PARTICLES
ENERGY TRANSFER
ENERGY-LEVEL TRANSITIONS
FERMIONS
HEAT TRANSFER
HEATING
LEPTONS
MATHEMATICAL MODELS
RADIATION FLUX
RADIATION TRANSPORT
RADIATIONS
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SOLAR CORONA
SOLAR ELECTRONS
SOLAR FLARES
SOLAR PARTICLES
SOLAR RADIATION
STAR MODELS
STELLAR ATMOSPHERES
STELLAR CORONAE
STELLAR RADIATION
THERMAL CONDUCTION