带权重的相关函数在半解析模型和SDSS数据中的应用

Marked Correlations between Semi-analytical Models and SDSS

基于半解析模型和SDSS DR4(Sloan Digital Sky Survey Data Release 4),研究了环境对星系性质的影响.通过对以颜色、恒星形成率和恒星质量的带权重的相关函数的测量,发现半解析模型在颜色和恒星质量上与SDSS数据符合得比较好,而恒星形成率则在SDSS数据中表现为与环境无关.此结论证实了半解析模型对星系中部分性质与环境关系的预测,但对于恒星形成率为何与环境无关仍有待研究.

Using the ＂marked＂ correlation function, the dependence of galaxy clustering on their properties is investigated. We measured the color-, star formation rate- and stellar mass-weighted or ＂marked＂ correlation functions in the SDSS DR4 galaxy catalog, and then compare with the mock catalog produced by the semi-analytical model （SAM） of galaxy formation. It is shown that the SAM can be in good agreement with the SDSS observations while taking the color and stellar mass as marked galactic properties. However, one striking feature revealed by the SDSS sample is the independence of the galaxy clustering on the star formation rate, which shows a significant discrepancy with what predicted by the SAM, and it remains a worthy issue for the further study.