4956
Radwa Mahmoud Amin Abdel-megeed
Computational Developments for Distance Determination and velocity ellipsoid Distribution of Stellar Groups
distances determination / velocity ellipsoid
One of the most crucial pieces of information needed in astronomy is the distance to stars and cosmic groups. A new statistical method for cosmic distances determination was developed. The method depends on the assumption that the members of the group scatter around a mean absolute magnitude in Gaussian distribution. The mean apparent magnitude of the members is then expressed by frequency function to correct for observational incompleteness at the faint end. The problem is reduced to the solution of a highly transcendental equation for a given magnitude parameter (α).Full Computational developments of the method was recently established. The present thesis is addressed to study three important subjects in the field of astrophysics (galactic structure).The first subject we present an introduction about the two subjects of present thesis and some important definitions. The second subject is dealing with the distance of stellar groups. For this study we use the same assumptions, and transcendental equation but with new semi analytical solution of the distance, compute the distance of selected stellar groups using developed methods, establish the frequency functions Ф (M) and ψ (m) of absolute and apparent magnitudes for the selected stellar groups, provide some basic descriptive statistical parameters for apparent and absolute magnitudes of some selected stellar groups.
2015
M.Sc
Zagazig
Science