Hydrogen line diagnostics in impulsive flares

Thesis/Dissertation · Mon Jan 01 04:00:00 EST 1990

OSTI ID:5312775

Gayley, K G

Frequency- and angle-dependent radiative transfer in models of impulsively heated solar flare chromospheres are studied and the resulting hydrogen line diagnostics are investigated. The method handles superthermal flows, and includes partially coherent scattering effects in the Lyman wings. The focus is on diagnostics of chromospheric shocks, condensations, and nonthermal electron heating, in order to guide the interpretation of Lyman alpha and Balmer alpha observations of impulsive events in solar-like chromospheres. The primary conclusions with respect to Lyman alpha diagnostics involve inferring flare temperatures and mass motions from red-shifted and stationary core emission, and extracting information about the flare heating that penetrates the chromosphere from the Stark-redistributed wing emission. How the degree of coherence in the wing scattering affects profile asymmetry, and how this depends on free electron density is considered. The primary conclusions with respect to diagnostics of Balmer alpha are conceptually similar to those of Lyman alpha, although the magnitude of wing brightening and the temperature sensitivity of core emission are modified. Owing to the parallel nature of the Lyman and Balmer diagnostics, compelling conclusions can be drawn from simultaneous line profile observations. When Lyman alpha observations are not available, simultaneous observations in two or more Balmer lines would also be useful.

• Research Organization: California Univ., San Diego, CA (United States)
• OSTI ID: 5312775
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
CHROMOSPHERE
DATA
ELEMENTS
ENERGY TRANSFER
HEAT TRANSFER
HEATING
HYDROGEN
INFORMATION
LYMAN LINES
MATHEMATICAL MODELS
NONMETALS
NUMERICAL DATA
PLASMA HEATING
RED SHIFT
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SOLAR FLARES
STAR MODELS
TEMPERATURE EFFECTS
THEORETICAL DATA