| Summary: | 碩士 === 國立中央大學 === 天文研究所 === 98 === We estimate the relations between the true axial ratios and the redshifts of elliptical galaxies. The sample is selected from SDSS DR7, which contains 69720 elliptical galaxies with redshifts from 0.01 to 0.30, angular size larger than 2 arcsec. We consider triaxial ellipsoids to be the model of elliptical galaxies, and adopt Gaussian distributions for the axial ratios to fit the observations. This problem is a question of Fredholm integral equation of the first kind. Our result shows that the real shape of elliptical galaxies distributes in a smaller range as redshift increases, and the most probable axial ratios of middle-to-major are between 0.77 and 0.65, ratios of minor-to-major are between 0.85 and 0.74, change as redshift increases.
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