Young stellar groups in M 33 galaxy: delineation and main parameters

TL;DR

This study investigates the sizes and structures of stellar groups in the M 33 galaxy using deep photometry, comparing classical associations with objectively identified stellar groups to understand their main parameters.

Contribution

It introduces an objective method for delineating stellar groups and compares these with classical associations, providing new insights into their sizes, shapes, and densities.

Findings

Classical OB associations are compared with objectively selected stellar groups.

Main parameters like size, shape, and density are quantified.

The study questions the existence of a typical size for stellar associations.

Abstract

The problem of (non-)existence of a typical size of the stellar associations is revisited by use of deep UBVRI stellar CCD photometry in M 33 from the Local Group Survey (Massey et al. 2006). We compare the outlines of the `classical OB associations' (Ivanov 1991) with stellar groups that were selected through an objective method for determination of the local stellar density and delineation. Main parameters of some stellar groups like size, shape and density concentrations are determined.