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XMMGPS - XMM-Newton Galactic Plane Survey - XGPS

HEASARC
Archive

Overview

This table contains the first results from the XMM-Newton Galactic Plane Survey (XGPS). In the first phase of the program, 22 pointings were used to cover a region of approximately 3 square degrees between 19 and 22 degrees in Galactic Longitude and +/-0.6 degrees in Galactic Latitude. In total, over 400 point X-ray sources have been resolved at >=5-sigma significance, down to a flux limit of ~2 x 10^-14 erg/s/cm^2 (2-10 keV). The sources exhibit a very wide range of spectral hardness, with interstellar absorption identified as a major influence. The source populations detected in the soft (0.4 - 2 keV) band and hard (2 - 6 keV) band show surprisingly little overlap. The majority of the soft sources appear to be associated with relatively nearby stars with active stelaar coronae, judging from their high coincidence with bright stellar counterparts. The combination of the XGPS measurements in the hard X-ray band with the results from earlier surveys carried out by ASCA and Chandra reveals the form of the low-latitude X-ray source counts over 4 decades of flux. It appears that extragalactic sources dominate below ~10^-13 erg/s/cm^2 (2-10 keV), with a predominantly Galactic source population present above this flux threshold. The nature of the faint Galactic population observed by XMM-Newton remains uncertain, although cataclysmic variables and RS CVn systems may contribute substantially.

Catalog Bibcode

2004MNRAS.351...31H

References

X-ray source populations in the Galactic plane.
    Hands A.D.P., Warwick R.S., Watson M.G., Helfand D.J.
   <Mon. Not. R. Astron. Soc., 351, 31-56 (2004)>
   =2004MNRAS.351...31H    (SIMBAD/NED BibCode)

Provenance

This table was created by the HEASARC in February 2005 based on CDS Catalog J/MNRAS/351/31/tablea1.dat.

HEASARC Implementation

All count rates and their associated errors are given in counts per second (ct/s) in this HEASARC table, whereas they were given in counts per kilosecond (ct/ks) in the original version of this table as published.

Parameters

Name
The recommended designation for X-Ray sources in this catalog, using the XGPS-I prefix for XMM Galactic Plane Survey, First Phase, and the usual position-based descriptor.

Survey_Field
The XGPS-I comprises 22 separate XMM-Newton pointings carried out during the period from 2000 October and 2003 April. The details of these pointings are given in Table 1 of the published paper. This parameter contains the shortened names of the survey field in which the particular source was detected: e.g., 'R1' for the Ridge 1 field or 'X5' for the XGPS 5 field.

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

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

LII
The Galactic Longitude of the X-ray source.

BII
The Galactic Latitude of the X-ray source.

Mos_Soft_Rate
The EPIC MOS soft-band (0.4 - 2.0 keV) count rate, in ct/s, corrected for background counts and vignetting. Note that all the count rates in this table are measured count rates and have not been corrected for the signal loss due to the limited 16-arcsecond size of the source cell (as discussed in Section 3.2 of the published paper, the average aperture correction factor for this size source cell is is 1/0.7=1.43); also, negative count rates have been set to zero.

Mos_Soft_Rate_Error
The RMS uncertainty in the MOS soft-band count rate, in ct/s.

Mos_Hard_Rate
The EPIC MOS hard-band (2.0 - 6.0 keV) count rate, in ct/s, corrected for background counts and vignetting. Note that all the count rates in this table are measured count rates and have not been corrected for the signal loss due to the limited 16-arcsecond size of the source cell (as discussed in Section 3.2 of the published paper, the average aperture correction factor for this size source cell is is 1/0.7=1.43); also, negative count rates have been set to zero.

Mos_Hard_Rate_Error
The RMS uncertainty in the MOS hard-band count rate, in ct/s.

Mos_Count_Rate
The EPIC MOS broad-band (0.4 - 6.0) count rate, in ct/s, corrected for background counts and vignetting. Note that all the count rates in this table are measured count rates and have not been corrected for the signal loss due to the limited 16-arcsecond size of the source cell (as discussed in Section 3.2 of the published paper, the average aperture correction factor for this size source cell is is 1/0.7=1.43); also, negative count rates have been set to zero.

Mos_Count_Rate_Error
The RMS uncertainty in the MOS broad-band count rate, in ct/s.

Mos_Quality_Flag
The MOS quality flag parameter, being the fraction of `good pixels' in the source cell. This parameter is particularly useful in flagging sources near CCD chip gaps or distorted by bad columns in the CCD.

PN_Soft_Rate
The EPIC PN soft-band (0.4 - 2.0 keV) count rate, in ct/s, corrected for background counts and vignetting. Note that all the count rates in this table are measured count rates and have not been corrected for the signal loss due to the limited 16-arcsecond size of the source cell (as discussed in Section 3.2 of the published paper, the average aperture correction factor for this size source cell is is 1/0.7=1.43); also, negative count rates have been set to zero.

PN_Soft_Rate_Error
The RMS uncertainty in the PN soft-band count rate, in ct/s.

PN_Hard_Rate
The EPIC PN hard-band (2.0 - 6.0 keV) count rate, in ct/s, corrected for background counts and vignetting. Note that all the count rates in this table are measured count rates and have not been corrected for the signal loss due to the limited 16-arcsecond size of the source cell (as discussed in Section 3.2 of the published paper, the average aperture correction factor for this size source cell is is 1/0.7=1.43); also, negative count rates have been set to zero.

PN_Hard_Rate_Error
The RMS uncertainty in the PN hard-band count rate, in ct/s.

PN_Count_Rate
The EPIC PN broad-band (0.4 - 6.0 keV) count rate, in ct/s, corrected for background counts and vignetting. Note that all the count rates in this table are measured count rates and have not been corrected for the signal loss due to the limited 16-arcsecond size of the source cell (as discussed in Section 3.2 of the published paper, the average aperture correction factor for this size source cell is is 1/0.7=1.43); also, negative count rates have been set to zero.

PN_Count_Rate_Error
The RMS uncertainty in the PN broad-band count rate, in ct/s.

PN_Quality_Flag
The PN quality flag parameter, being the fraction of `good pixels' in the source cell. This parameter is particularly useful in flagging sources near CCD chip gaps or distorted by bad columns in the CCD.

Hardness_Ratio
The X-Ray spectral hardness ratio, HR, defined as HR = (H-S)/(H+S), where H is the number of counts measured in the hard band, and S is the corresponding number of soft counts. For sources detected in both the PN and the MOS camera systems, the authors summed the PN and MOS counts in the two energy bands before calculating HR. A correction for the differential vignetting was not applied to the HR value because this was generally small compared to the statistical error.

Rmag
The R magnitude of the brightest optical source within a 6 arcsecond error circle based on the SuperCOSMOS digitisation of the R plate from the UK Schmidt Survey.

Alt_Name_1
The designation of the optical source, if any, within a 6 arcsecond X-ray error circle. Here U means USNO, and all the other references have been taken from SIMBAD database.

Alt_Name_2
An alternative designation of the optical source, if any.

Alt_Name_3
Another alternative designation of the optical source, if any.


Contact Person

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

Page Author: Browse Software Development Team
Last Modified: 28-Feb-2005