NGC 6357: Chandra X-Ray Catalog of 800 Stellar Sources

Approximately 800 X-ray sources were detected in a 38 ks Chandra/ACIS observation of the massive star-forming region NGC 6357, providing a probe of its intermediate-mass and low-mass stellar population. The catalog, produced by NASA, includes candidate O stars and the first X-ray detection from an evaporating gaseous globule, with data from an observation on 2004 July 9. This work increased the number of known cluster members from optical studies by a factor of roughly 50.

Use Cases

• Study the initial mass function of the Pismis 24 cluster based on the detected X-ray source population.
• Analyze the correlation between X-ray and bolometric luminosity for O stars using the confirmed L_X ~ 10^-7 L_bol relationship.
• Investigate star formation in molecular pillars using the X-ray detection from an evaporating gaseous globule.
• Compare the high-luminosity end of the X-ray luminosity function with other regions like the Orion Nebula Cluster.

Strengths

• Contains approximately 800 X-ray sources, providing a significant increase over previous optical studies.
• Data originates from a high spatial resolution 38 ks Chandra observation with a limiting sensitivity of ~10^30 erg s^-1.
• Includes cross-matching to the 2MASS point source catalog for improved astrometry and multi-wavelength analysis.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data is from a single observation in 2004; temporal changes are not captured.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Data reduction from a Chandra/ACIS-I observation (ID 4477) using the CIAO package and wavdetect algorithm, matched to 2MASS.

Time Range

Observation date 2004-07-09.

Freshness

Last updated 2026-03-13 18:32:15.174528; freshness should be verified.

Geography

Covers the massive star-forming region NGC 6357, centered on the Pismis 24 cluster (field of view ~17x17 arcminutes).