The Clustering Properties of the Young Stars in Orion a and lambda Orionis

C. J. LADA, M. GÓMEZ

Montevideo

Congreso; VIII Reunion Regional LatinoAmericana de Astronomia Union Astronomica Internacional; 1995

IAU

Using synthetic models we investigate the possibilities of the two-point angular correlation function as a clustering searching/analyzing tool. We are particulary interested in the physical interpretation of features in the correlation function such as: power-law indexes, breaking points, and scale at which the correlation function goes to zero. In general, breaks are related with the clusters´ radii and the correlation function goes to zero at the length of the clusters´ configuration. The influences in the correlation function features of a background population in which the clusters may be embedded are also tested. The main effect depends critically on the density constrast between the clusters and the background population and it is to dilute features in the correlation function.This technique is applie to the study of the clustering properties of the Halpha emission and OB stars in Orion A and the lambda Orionis association. The correlation functions for the Halpha and the OB stars in Orion A are fitted by power-laws.