Application of Weighted Correlation Functions to Semi-analytic Models and SDSS Data

The effect of circumstances on the properties of galaxies is researched on the basis of semi-analytic models and SDSS DR4 (Sloan Digital Sky Survey Data Release 4). From the measurements of the weighted correlation function with the color, star formation rate and stellar mass, it is found that the semianalytic models are in good accordance with the SDSS data in color and stellar mass, while the star formation rate manifests itself as a thing that has no relation to the circumstances in the SDSS data. This conclusion confirms the prediction of the relation between some properties in a galaxy and the circumstances, made by means of the semi-analytic model, but the reason why the star formation rate has no relation to the circumstances still remains to be studied.