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NGC 6231 XMM-Newton X-Ray Source Catalog

Metadata Updated: April 10, 2026

This table contains the results of an X-ray campaign towards the young open cluster NGC 6231. The XMM-Newton observations, of a total duration of ~ 180 ks, reveal that NGC 6231 is very rich in the X-ray domain too. Indeed, 610 X-ray sources were detected in the present field of view, centered on the colliding wind binary HD 152248 in the cluster core (RA, Dec J2000.0 of 16 54 10.06, -41 49 30.1). The limiting sensitivity of this survey is approximately 6 x 10^-15<sup>erg/s/cm</sup>2 but clearly depends on the location in the field of view and on the source spectrum. Using different existing catalogs, over 85% of the X-ray sources could be associated with at least one optical and/or infrared counterpart within a limited cross-correlation radius of 2.5 or 3-arcsec according to the optical/IR catalog used. The surface density distribution of the X-ray sources presents a slight N-S elongation. Once corrected for the spatial sensitivity variation of the EPIC instruments, the radial profile of the source surface density is well described by a King profile with a central density of about 8 sources per arcmin<sup>2</sup> and a core radius close to 3.1 arcminutes. The distribution of the X-ray sources seems closely related to the optical source distribution. The expected number of foreground and background sources should represent about 9% of the detected sources, thus strongly suggesting that most of the observed X-ray emitters are physically belonging to NGC 6231. Finally, beside a few bright but soft objects -- corresponding to the early-type stars of the cluster -- most of the sources are relatively faint (~5 x 10<sup>-15</sup> erg/s/cm<sup>2</sup>) with an energy distribution peaked around 1.0 - 2.0 keV. The catalog of the 610 X-ray sources detected in the 30'-diameter field of view of XMM-Newton is presented here, including the equatorial coordinates, logarithmic likelihoods and count rates for the three EPIC instruments and for various energy ranges, as well as the cross-identification of the X-ray sources with various optical/infrared catalogs (2MASS, GSC2.2, USNO B1.0, SSB06) and their most commonly used names (HD/HDE, CD, CPD, Segg., SBL98, Braes), with only the closest identifications being reported here. This table was created by the HEASARC in March 2007 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/454/1047">CDS catalog J/A+A/454/1047</a> files table3.dat and table6.dat. This is a service provided by NASA HEASARC .

Access & Use Information

Public: This dataset is intended for public access and use. License: See this page for license information.

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Dates

Metadata Created Date April 11, 2025
Metadata Updated Date April 10, 2026

Metadata Source

Harvested from NASA Data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date April 11, 2025
Metadata Updated Date April 10, 2026
Publisher High Energy Astrophysics Science Archive Research Center
Maintainer
Identifier ivo://nasa.heasarc/ngc6231xmm
Data Last Modified 2026-04-06
Category Astrophysics
Public Access Level public
Bureau Code 026:00
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id e55786b8-45ea-49a7-952c-294e8c3b73b8
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Homepage URL ivo://nasa.heasarc/ngc6231xmm
License https://www.usa.gov/government-works
Program Code 026:000
Source Datajson Identifier True
Source Hash b5e49eb8998c9e9dc12e825063b0efd31e9ee2992a33cacd28d0a9a83ddb8e6b
Source Schema Version 1.1

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