The Young Stellar Population of the Cygnus-X DR15 Region

TL;DR

This study characterizes the young stellar population in Cygnus-X DR15 using multi-wavelength data, revealing cluster structures, age estimates, and gas dispersal timescales, suggesting a prolonged star formation process over several million years.

Contribution

It provides a detailed multi-wavelength analysis of young stars in DR15, including spatial distribution, age estimation, and gas kinematics, highlighting the slow dispersal of molecular gas in this region.

Findings

226 young stellar sources identified and classified.

Multiple star groups with varying ages and gas structures.

Gas dispersal in DR15 is slower than in other regions.

Abstract

We present a multi-wavelength study of the young stellar population in the Cygnus-X DR15 region. We studied young stars forming or recently formed at and around the tip of a prominent molecular pillar and an infrared dark cloud. Using a combination of ground based near-infrared, space based infrared and X-ray data, we constructed a point source catalog from which we identified 226 young stellar sources, which we classified into evolutionary classes. We studied their spatial distribution across the molecular gas structures and identified several groups possibly belonging to distinct young star clusters. We obtained samples of these groups and constructed K-band luminosity functions that we compared with those of artificial clusters, allowing us to make first order estimates of the mean ages and age spreads of the groups. We used a $^{13}$CO(1-0) map to investigate the gas kinematics at the prominent gaseous envelope of the central cluster in DR15, and we infer that the removal of this envelope is relatively slow compared to other cluster regions, in which gas dispersal timescale could be similar or shorter than the circumstellar disk dissipation timescale. The presence of other groups with slightly older ages, associated with much less prominent gaseous structures may imply that the evolution of young clusters in this part of the complex proceeds in periods that last 3 to 5 Myr, perhaps after a slow dissipation of their dense molecular cloud birthplaces.