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ASCA GIS Source Catalog (AMSS-I + AMSS-II)

Metadata Updated: February 6, 2026

This is the complete X-ray source catalog of the ASCA Medium Sensitivity Survey, AMSS, or the Gas Imaging Spectrometer (GIS) catalog project. It has been constructed from data for fields covering Galactic latitudes |b| > 10 degrees which were obtained with the GIS instrument onboard the ASCA satellite between 1993 May and 1996 December (part I) and between 1997 January and 2000 May (part II). Part I of this catalog (AMSS-I) utilizes 368 combined fields, and contains 1343 sources (including target sources) with detection significance above 5 sigma in at least one of the 3 survey bands of 0.7-7.0, 2-10, or 0.7-2.0 keV, while AMSS-II uses 306 fields, and contains a total of 1190 sources, using the same criteria. The AMSS-I and AMSS-II catalogs together contain 2533 sources from an area of 278 square degrees and provide a unique database of X-ray sources in the flux range of 10<sup>-13</sup> to 10<sup>-11</sup> erg cm<sup>-2</sup> s<sup>-1</sup> (0.7-10 keV). The published paper contains a summary of the statistical properties of a complete X-ray sample consisting of 1969 serendipitous sources selected from AMSS-I and AMSS-II. For each source, the ASCA source name, position, 90% error radius, count rates (both observed and as corrected for Galactic absorption) in the 3 energy bands, detection signifances and fluxes in the 3 energy bands, and hardness ratio and associated error are provided. This version of the Browse ASCAGIS table containing the combined AMSS-I and AMSS-II source lists was created by the HEASARC in February 2006 based on the CDS version of the AMSS-I source list (<a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/133/1">CDS catalog J/ApJS/133/1</a>) and the electronic ApJS version of the AMSS-II source list. 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 9, 2025
Metadata Updated Date February 6, 2026

Metadata Source

Harvested from NASA Data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date April 9, 2025
Metadata Updated Date February 6, 2026
Publisher High Energy Astrophysics Science Archive Research Center
Maintainer
Identifier ivo://nasa.heasarc/ascagis
Data Last Modified 2026-02-03
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 f0f36f4b-57ba-4175-be27-b48124bceb7c
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Homepage URL https://heasarc.gsfc.nasa.gov/W3Browse/all/ascagis.html
Program Code 026:000
Source Datajson Identifier True
Source Hash 6b982bb182d8dd6f62be5da9f182b8dcc7f90ce3c93454c395a35b89a1582c22
Source Schema Version 1.1

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