Stellar Clusters in the NGC 6334 Star Forming Complex

TL;DR

This study uses Chandra X-ray data to identify and analyze 1607 faint X-ray sources in NGC 6334, revealing about 20,000-30,000 pre-main sequence stars across multiple clusters, advancing understanding of massive star formation.

Contribution

It provides the first comprehensive X-ray catalog of NGC 6334, identifying numerous new clusters and estimating the total stellar population with detailed spatial distribution.

Findings

Identified 1607 X-ray sources in NGC 6334.

Estimated total stellar population of 20,000-30,000 pre-main sequence stars.

Discovered multiple star clusters with varying levels of obscuration.

Abstract

The full stellar population of NGC 6334, one of the most spectacular regions of massive star formation in the nearby Galaxy, have not been well-sampled in past studies. We analyze here a mosaic of two Chandra X-ray Observatory images of the region using sensitive data analysis methods, giving a list of 1607 faint X-ray sources with arcsecond positions and approximate line-of-sight absorption. About 95 percent of these are expected to be cluster members, most lower mass pre-main sequence stars. Extrapolating to low X-ray levels, the total stellar population is estimated to be 20-30,000 pre-main sequence stars. The X-ray sources show a complicated spatial pattern with about 10 distinct star clusters. The heavily-obscured clusters are mostly associated with previously known far-infrared sources and radio HII regions. The lightly-obscured clusters are mostly newly identified in the X-ray images. Dozens of likely OB stars are found, both in clusters and dispersed throughout the region, suggesting that star formation in the complex has proceeded over millions of years. A number of extraordinarily heavily absorbed X-ray sources are associated with the active regions of star formation.