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Groth-Westphal Strip Chandra X-Ray Point Source Catalog

Metadata Updated: April 10, 2026

This table contains the optical and X-ray spectral properties of the sources detected in a 200-ks Chandra observation of part of the Groth-Westphal Strip (GWS) region, using the ACIS-I instrument. The authors present a relatively simple method for the detection of X-ray point sources and the calculation of limiting sensitivities, which they argue is at least as sensitive and more self-consistent than previous methods presented in the literature. A total of 158 distinct X-ray sources are included in this point-source catalogue in the ACIS-I area with a threshold Poisson detection probability of 4 x 10<sup>-6</sup>. The number counts show a relative dearth of X-ray sources in this region. A wealth of optical photometric and spectroscopic data are available in this field providing optical identifications and redshift determinations for the X-ray population. The optical photometry and spectroscopy used here are primarily from the Deep Extragalactic Evolutionary Probe 2 (DEEP2) survey with additional redshifts obtained from the literature. These are complemented with the deeper (r ~ 26 mag) multiwaveband data (ugriz) from the Canada-France-Hawaii Telescope Legacy Survey to estimate photometric redshifts and to optically identify sources fainter than the DEEP2 magnitude limit (R<sub>AB</sub> ~ 24.5 mag). The authors focus their study on the 2 - 10 keV selected sample comprising 97 sources to the flux limit ~8 x 10<sup>-16</sup> erg/s/cm<sup>2</sup>, this being the most complete in terms of optical identification rate (86 per cent) and redshift determination fraction (63 per cent; both spectroscopic and photometric). Chandra observed the GWS, which is part of the Extended Groth Strip (EGS) region, on three separate occasions between 2002 August 11 and 22, using ACIS-I as the prime instrument. The S2 and S3 chips of the ACIS-S array were also operating during the observation, but as these are far off-axis their data are not considered further. The sequence number identifying the observations was 900144 and the three observation ID numbers (3305 on 2002-08-11, 4357 on 2002-08-12, and 4365 on 2002-08-21). This table was created by the HEASARC in July 2007 based on the merger of <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/356/568">CDS Catalog J/MNRAS/356/568</a> file table3.dat and <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/371/221">CDS Catalog J/MNRAS/371/221</a> file table2.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.

Downloads & Resources

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/gwsstrpcxo
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 c0c261c7-52b4-475d-b57d-42ffe66680cf
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Homepage URL ivo://nasa.heasarc/gwsstrpcxo
License https://www.usa.gov/government-works
Program Code 026:000
Source Datajson Identifier True
Source Hash dc2ac27a679e72730e71f04955aa43549db5699f0d9d8ac6047338d39a648914
Source Schema Version 1.1

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