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Orion Nebula Cluster Chandra HRC X-Ray Point Source Catalog

Metadata Updated: August 30, 2025

In the first of two companion papers on the Orion Nebula Cluster (ONC), the authors presented their analysis of a 63 ks Chandra HRC-I observation that yielded 742 X-ray detections within the 30' x 30' field of view. To facilitate their interpretation of the X-ray image, they compiled a multi-wavelength catalog of nearly 2900 known objects in the region by combining 17 different catalogs from the recent literature. They defined two reference groups: an infrared sample, containing all objects detected in the K band, and an optical sample comprising low-extinction, well-characterized ONC members. They showed for both samples that field object contamination is generally low. Their X-ray sources are primarily low-mass ONC members. The detection rate for optical sample stars increases monotonically with stellar mass from zero at the brown dwarf limit to ~100% for the most massive stars but shows a pronounced dip between 2 and 10 M<sub>sun</sub>. They determined L<sub>X</sub> and L<sub>X</sub>/L<sub>bol</sub> or all stars in their optical sample and utilized this information in their companion paper to study correlations between X-ray activity and other stellar parameters. In particular, the authors assembled an extensive catalog of known X-ray/optical/IR and radio objects that fell within the HRC FOV. In addition to their list of HRC sources and the Chandra source lists of Garmire et al. (2000, <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/120/1426">CDS Cat. <J/AJ/120/1426></a>) and Schulz et al. (2001, CDS Cat. <J/ApJ/549/441>), they considered 14 catalogs from recent publications, producing a database of nearly 2900 distinct objects reported in at least one of the studies considered. A full list of references is given in the first column of Table 2 of the reference paper, along with a concise classification of the work and the referenced table number(s) from the original work. The HRC on board the Chandra X-Ray Observatory (Weisskopf et al., 2002PASP..114....1W) observed the ONC for 63.2ks on 2000 February 4. The pointing (R.A. = 5h 35m 17s, DE=-5{deg} 23' 16" (J2000.0)) was chosen to place the Trapezium region and the bright O star Theta<sup>1</sup> Ori C in the center of the field of view (FOV). A good fraction of the ONC region was included in the 30' x 30' HRC FOV. This HEASARC table lists the properties of the 742 X-ray sources detected in this observation as presented in the full version of Table 1 of the reference paper. This table was created by the HEASARC in March 2007 based on the CDS table J/ApJ/582/382, file table1.dat. This is a service provided by NASA HEASARC .

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Dates

Metadata Created Date April 11, 2025
Metadata Updated Date August 30, 2025

Metadata Source

Harvested from NASA Data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date April 11, 2025
Metadata Updated Date August 30, 2025
Publisher High Energy Astrophysics Science Archive Research Center
Maintainer
Identifier ivo://nasa.heasarc/onccxoxray
Data Last Modified 2025-08-27
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 e1a47985-6504-4645-b972-0d3d3f59c5e9
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Homepage URL https://heasarc.gsfc.nasa.gov/W3Browse/all/onccxoxray.html
Program Code 026:000
Source Datajson Identifier True
Source Hash 1b78141cc4376538f5be702bf3166e082eb570090c570a9610c3a27b1ab45c5d
Source Schema Version 1.1

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