Accession Number : AD0715616

Title :   Determination of Macroscopic Velocities from Line Profile Asymmetries,

Corporate Author : GENERAL ELECTRIC CO PHILADELPHIA PA MISSILE AND SPACE DIV

Personal Author(s) : Kulander,J. L.

Report Date : DEC 1964

Pagination or Media Count : 42

Abstract : Synthetic line profiles are generated for model atmospheres containing linear and quadratic velocity fields and various temperature distributions. LTE and non-LTE source functions and both weak and strong lines are considered. Comparison of the assumed velocity structures with those inferred from the bisector shifts of the asymmetrical profiles show qualitative correlation only in the line cores and in general only for velocities small compared with the thermal velocity. A constant asymptotic velocity is inferred in the semi-infinite atmospheres below certain limiting depths for both strong and weak lines. Approximate expressions relating observed profile parameters to atmospheric velocity parameters for small linear velocities are obtained and tested for the constant temperature case. The observed rms displacements in the solar H-alpha line are used to infer the amplitude of the oscillatory velocity field in that region of the solar chromosphere where the core is formed. (Author)

Descriptors :   (*SOLAR ATMOSPHERE, ATMOSPHERE MODELS), VELOCITY, LINE SPECTRA, SPECTRUM ANALYZERS, STARS, SOLAR SPECTRUM, MAGNETOHYDRODYNAMICS, OSCILLATION, CHROMOSPHERE, DOPPLER EFFECT

Subject Categories : Astrophysics

Distribution Statement : APPROVED FOR PUBLIC RELEASE