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

HEASARC
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Overview

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^-13 to 10^-11 erg cm^-2 s^-1 (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.


Catalog Bibcodes

2005ApJS..161..185U
2001ApJS..133....1U

References

The ASCA Medium Sensitivity Survey (the GIS Catalog Project): Source Catalog.
    Ueda Y., Ishisaki Y., Takahashi T., Makishima K., Ohashi T.
   <Astrophys. J. Suppl. Ser. 133, 1 (2001)>
   =2001ApJS..133....1U

The ASCA Medium Sensitivity Survey (the GIS Catalog Project): Source Catalog II.
    Ueda Y., Ishisaki Y., Takahashi T., Makishima K., Ohashi T.
   <Astrophys. J. Suppl. Ser. 161, 185 (2005)>
   =2005ApJS..161..185U

Provenance

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 (CDS catalog J/ApJS/133/1) and the electronic ApJS version of the AMSS-II source list.

Parameters

Name
The ASCA source name constructed in the recommended IAU fashion, using the prefix '1AXG (1st ASCA X-Ray GIS source) and the J2000 equatorial coordinates.

RA
The Right Ascension of the source. This was provided in J2000 degrees with a precision of 0.0001 degrees in the original tables.

Dec
The Declination of the source. This was provided in J2000 degrees with a precision of 0.0001 degrees in the original tables.

LII
The Galactic Longitude of the source.

BII
The Galactic Latitude of the source.

Error_Radius
The positional error radius (90% confidence), including both the statistical and systematic errors, in arcminutes. See Section 3.3 of Paper I for more details.

SNR_Total
The detection significance, i.e., number of sigma, in the 0.7-7 keV band.

SNR_Hard
The detection significance, i.e., number of sigma, in the 2-10 keV band.

SNR_Soft
The detection significance, i.e., number of sigma, in the 0.7-2 keV band.

Count_Rate_Total
The vignetting-corrected "observed" count rate in the 0.7-7 keV band at the reference position in the X-Ray Telescope coordinate (8.5' offset) integrated within a radius of 5.9', in counts per second. This has not been corrected for Galactic absorption.

Count_Rate_Hard
The vignetting-corrected "observed" count rate in the 2-10 keV band, at the reference position in the X-Ray Telescope coordinate (8.5' offset) integrated within a radius of 5.9', in counts per second. This has not been corrected for Galactic absorption.

Count_Rate_Soft
The vignetting-corrected "observed" count rate in the 0.7-2.0 keV band, at the reference position in the X-Ray Telescope coordinate (8.5' offset) integrated within a radius of 5.9', in counts per second. This has not been corrected for Galactic absorption.

Corr_Count_Rate_Total
The 0.7-7 keV count rate, in counts per second, corrected for Galactic interstellar absorption using the Dickey and Lockman (1990, ARA&A, 28, 215) estimate.

Corr_Count_Rate_Hard
The 2-10 keV count rate, in counts per second, corrected for Galactic interstellar absorption using the Dickey and Lockman (1990, ARA&A, 28, 215) estimate.

Corr_Count_Rate_Soft
The 0.7-2 keV count rate, in counts per second, corrected for Galactic interstellar absorption using the Dickey and Lockman (1990, ARA&A, 28, 215) estimate.

Flux_Total
The 0.7-7 keV flux, in cgs units of erg/s/cm^2, corrected for Galactic interstellar absorption. This flux has been obtained using the observed count rate in the same band and assuming a power-law with Galactic absorption, with the best-fit photon index derived from the observed hardness ratio HR1. See Section 2.4 of Paper I for more details.

Flux_Hard
The 2-10 keV flux, in cgs units of erg/s/cm^2, corrected for Galactic interstellar absorption. This flux has been obtained using the observed count rate in the same band and assuming a power-law with Galactic absorption, with the best-fit photon index derived from the observed hardness ratio HR1. See Section 2.4 of Paper I for more details.

Flux_Soft
The 0.7-2 keV flux, in cgs units of erg/s/cm^2, corrected for Galactic interstellar absorption. This flux has been obtained using the observed count rate in the same band and assuming a power-law with Galactic absorption, with the best-fit photon index derived from the observed hardness ratio HR1. See Section 2.4 of Paper I for more details.

HR1
The hardness ratio, HR1, defined as HR1 = (H-S)/(H+S), where H is corr_count_rate_hard (the 2-10 keV count rate corrected for Galactic interstellar absorption) and S is corr_count_rate_soft (the 0.7-2 keV flux, corrected for Galactic interstellar absorption).

HR1_Error
The 1-sigma statistical error in the hardness ratio, HR1.

Field_ID
The identification of the field in which the source was detected. The information on these fields is given in Table 1 of AMSS-I for fields starting with 'I-' and Table 1 of AMSS-II for fields starting with 'II-'.

Target_Flag
This parameter is a flag which to set to 'Y' to indicate that the source was the target of the ASCA observation.

Catalog_Part
This parameter is a flag which indicates from which part of the AMSS Catalog the entry originates ('I' for AMSS-I, 'II' for AMSS-II).

Duplicate_Source
This parameter is a flag which is set to 'Y' to indicate that the entry is likely a duplicate of another AMSS source, else it is set to 'N'. Most (81/86) of the duplicates are AMSS-I sources that were independently redetected in AMSS-II, with the remainder being sources that were duplicated within AMSS-I. To identify duplicates, the authors looked for pairs if sources whose positions coincided within twice the combined 90% positional errors. 85 of the 86 duplicates are listed in Table 4 of Paper II, while the remaining duplicate pair (the two sources with the identical name 1AXG J053056+1331 in AMSS-I) was noticed by the HEASARC while compiling the Browse version of this table.


Contact Person

Questions regarding the ASCAGIS database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 14-Feb-2006