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XMM-Newton Wide Angle Survey

Metadata Updated: January 16, 2026

This table contains results from the XMM-Newton Wide Angle Survey (XWAS), viz., a new catalog of almost a thousand X-ray sources that have been spectroscopically identified through optical observations. The sources lie in high-galactic latitude (|b| > 20 degrees) XMM-Newton fields mainly in the southern hemisphere. A sample of X-ray sources detected in 68 XMM-Newton pointed observations was selected for optical multi-fiber spectroscopy. Optical counterparts and corresponding photometry of the X-ray sources were obtained from the SuperCOSMOS Sky Survey. Candidates for spectroscopy were initially selected with magnitudes down to R ~ 21, with preference for X-ray sources having a flux F<sub>0.5-4.5keV</sub> >= 10<sup>-14</sup> erg/s/cm<sup>2</sup>. Optical spectroscopic observations were made using the Two Degree Field of the Anglo-Australian Telescope, and the resulting spectra were classified based on optical emission lines. The authors have identified through optical spectroscopy 940 X-ray sources over a solid angle Omega ~ 11.8 deg<sup>2</sup> of the sky. Source populations in their sample can be summarized as 65% broad-line active galactic nuclei (BLAGN), 16% narrow emission-line galaxies (NELGs), 6% absorption-line galaxies (ALGs) and 13% stars. An active nucleus is also likely to be present in the large majority of the X-ray sources spectroscopically classified as NELGs or ALGs. Optical images are available for all of the XWAS fields in the SuperCOSMOS Sky Survey (Hambly et al., 2001, MNRAS, 326, 1279). This table was created by the HEASARC in May 2017 based upon the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/557/A123">CDS Catalog J/A+A/557/A123</a> file xwas_cat.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.

Downloads & Resources

Dates

Metadata Created Date April 11, 2025
Metadata Updated Date January 16, 2026

Metadata Source

Harvested from NASA Data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date April 11, 2025
Metadata Updated Date January 16, 2026
Publisher High Energy Astrophysics Science Archive Research Center
Maintainer
Identifier ivo://nasa.heasarc/xwas
Data Last Modified 2026-01-13
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 bbae9764-f033-4eef-9b66-0d77eacdf56a
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Homepage URL https://heasarc.gsfc.nasa.gov/W3Browse/all/xwas.html
Program Code 026:000
Source Datajson Identifier True
Source Hash bf9072412c65a6411c28c9ddf9ceab989da98f22d1c4edae5deb0e5d4f38b2fb
Source Schema Version 1.1

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