Young Stellar Groups and Their Most Massive Stars

TL;DR

This study examines the properties of fourteen young stellar groups in nearby regions, revealing that they share key characteristics with larger clusters, including mass distribution and the central positioning of the most massive stars.

Contribution

It provides new insights into the structure and mass distribution of small young stellar groups, showing they exhibit properties similar to larger star clusters.

Findings

Most massive stars are centrally located within groups.

A correlation exists between the mass of the most massive star and total group mass.

A significant fraction of the group's mass is contained in a small number of stars.

Abstract

We analyze the masses and spatial distributions of fourteen young stellar groups in Taurus, Lupus3, ChaI, and IC348. These nearby groups, which typically contain 20 to 40 members, have membership catalogs complete to ~0.02 M_sun, and are sufficiently young that their locations should be similar to where they formed. These groups show five properties seen in clusters having many more stars and much greater surface density of stars: (1) a broad range of masses, (2) a concentration of the most massive star towards the centre of the group, (3) an association of the most massive star with a high surface density of lower-mass stars, (4) a correlation of the mass of the most massive star with the total mass of the group, and (5) the distribution of a large fraction of the mass in a small fraction of the stars.