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ARCQUINCXO - Arches and Quintuplet Clusters Chandra X-Ray Point Source Catalog

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Overview

The Galactic centre (GC) provides a unique laboratory for a detailed examination of the interplay between massive star formation and the nuclear environment of our Galaxy. Here are presented some of the results from a 100-ks Chandra Advanced CCD Imaging Spectrometer (ACIS) observation of the Arches and Quintuplet star clusters in the form of a catalog of 244 point-like X-ray sources detected in the observation.

The deep Chandra ACIS-I observation (Obs. ID: 4500) was carried out on 2004 June 9. The Arches cluster was placed about 1-arcmin away from the aim point to minimize the effect of the CCD gaps on mapping the extended X-ray emission around the cluster.


Catalog Bibcode

2006MNRAS.371...38W

References

The interplay between star formation and the nuclear environment of our Galaxy:
deep X-ray observations of the Galactic centre Arches and Quintuplet clusters.
    Wang Q.D., Dong H., Lang C.
   <Mon. Not. R. Astron. Soc., 371, 38-54 (2006)>
   =2006MNRAS.371...38W    (SIMBAD/NED BibCode)

Provenance

This table was created by the HEASARC in July 2007 based on CDS Catalog J/MNRAS/371/38 file table1.dat.

Parameters

Source_Number
A running X-ray source number in order of increasing J2000.0 Right Ascension for the first 235 sources which have individual local false detection probablilities P <= 10^-7). Sources 236 to 244 are the 9 sources found in the vicinity (2 x 3 square arcminutes) of the Arches and Quintuplet clusters for which a looser significance (10^-7 < P <= 10^-5) of being false was adopted.

Alt_Name
An alternative designation for the X-ray source using the '[WDL2006]' prefix (for Wang, Dong and Lang 2006) and the value of the source number parameter, as recommended by the CDS Dictionary of Nomenclature of Celestial Objects.

Source_Flag
This parameter is set to 'L' to indicate those sources (numbers 236 through 244 inclusive) found in the vicinity (2 x 3 square arcminutes) of the Arches and Quintuplet clusters for which a looser significance (10^-7 < P <= 10^-5) of being false was adopted.

Name
The preferred designation for the X-ray source using the 'CXOGCS' prefix (for Chandra X-Ray Observatory, Galactic Center Survey) and the J2000.0 coordinates (JHHMMSS.ss-DDMMSS.ss), as recommended by the CDS Dictionary of Nomenclature of Celestial Objects. Notice that in the reference paper, a slightly different (non-standard) prefix of 'CXGCS' was used.

RA
The Right Ascension of the X-ray source in the selected equinox. This was given in J2000.0 coordinates to a precision of 0.01 seconds of time in the original table (implicitly in the name of the source).

Dec
The Declination of the X-ray source in the selected equinox. This was given in J2000.0 coordinates to a precision of 0.1 arcseconds in the original table (implicitly in the name of the source).

LII
The Galactic Longitude of the X-ray source.

BII
The Galactic Latitude of the X-ray source.

Error_Radius
The positional uncertainty (1-sigma) of the X-ray source, in arcseconds, with the 1-sigma statistical error e calculated from the maximum-likelihood centroiding and an approximate off-axis angle-dependent systematic error E = 0.2" + 1.4"(r/8')^2, where r is the off-axis angle in arcminutes, added in quadrature (sqrt[e^2 + E^2]).

Count_Rate
The on-axis X-ray source broad-band count rate B in counts per second, i.e., the sum of the exposure-corrected count rates in the four energy bands S1 (1 - 2.5 keV), S2 (2.5 - 4.0 keV), H1 (4 - 6 keV), and H2 (6 - 9 keV). In addition, S = S1 + S2, H = H1 + H2 and B = S + H.

Count_Rate_Error
The RMS uncertainty in the on-axis X-ray source broad-band count rate, in counts per second.

Hardness_Ratio_1
The hardness ratio, HR1, defined as HR1 = (H - S2)/(H + S2) where the band count rates are defined above. This is listed only for sources which have HR1 values with uncertainties less than 0.2.

Hardness_Ratio_1_Error
The RMS uncertainty in HR1.

Hardness_Ratio_2
The hardness ratio, HR2, defined as HR2 = (H2 - H1)/(H) where the band count rates are defined above. This is listed only for sources which have HR2 values with uncertainties less than 0.2.

Hardness_Ratio_2_Error
The RMS uncertainty in HR2.

Detection_Bands
This parameter flags the bands in which a source was detected (B, S, and/or H). The band which generated the most accurate X-ray centroid position is listed first.


Contact Person

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

Page Author: Browse Software Development Team
Last Modified: 17-Jul-2007