Coordinates (20 columns)

RA (D) [deg] SAS task catcorr: Corrected Right Ascension of the detection in degrees (J2000) after statistical correlation of the emldetect coordinates, RA_UNC and DEC_UNC, with the USNO B1.0, 2MASS or SDSS (DR8) optical/IR source catalogues using the SAS task catcorr (the process of correcting the coordinates is also referred to as field rectification). In cases where the cross-correlation is determined to be unreliable, no correction is applied and this value is therefore the same as RA_UNC (cf. Sec. 3XMM-DR4 UG, Sec. 3.4).
DEC (D) [deg]SAS task catcorr: Corrected Declination of the detection in degrees (J2000) after statistical correlation of the emldetect coordinates, RA_UNC and DEC_UNC, with the USNO B1.0, 2MASS or SDSS (DR8) optical/IR source catalogues using the SAS task catcorr (the process of correcting the coordinates is also referred to as field rectification). In cases where the cross-correlation is determined to be unreliable no correction is applied and this value is therefore the same as DEC_UNC (cf. Sec. 3XMM-DR4 UG, Sec. 3.4).
POSERR (E) [arcsec]: Total radial position uncertainty in arcseconds calculated by combining the statistical error RADEC_ERR and the error arising from the field rectification process SYSERRCC as follows: POSERR = SQRT ( RADEC_ERR^2 + SYSERRCC^2 ). For a 2-dimensional Gaussian error distribution, this radius reflects a 63% probability that the true source position lies within this radius of the measured position. The corresponding 68% confidence radius is 1.0714*RADEC_ERR.
LII (D) [deg]SAS task catcorr: Galactic longitude of the detection in degrees corresponding to the (corrected) coordinates RA and DEC.
BII (D) [deg]SAS task catcorr: Galactic latitude of the detection in degrees corresponding to the (corrected) coordinates RA and DEC.
RADEC_ERR (E) [arcsec]SAS task emldetect: RADEC_ERR (E) [arcsec] is a radial error on the position, computed as sqrt( ra_err² + dec_err²), in arcsecs, where ra_err and dec_err are the 1 σ uncertainties in the RA and DEC coordinates respectively. The ra_err and dec_err quantities are provided, in image pixel units, in the X_IMA_ERR and Y_IMA_ERR columns, respectively, in the P*OMSRLI*.FIT pipeline product file of each observation - they are not provided directly in the catalogue.
SYSERRCC (E) [arcsec]SAS tasks catcorr: The estimated error arising from the field rectification process (in arcseconds). If the SAS task catcorr results in a statistically reliable cross-correlation with the USNO B1.0, 2MASS or SDSS (DR8) optical/IR catalogues, SYSERRCC combines the 1 σ errors on the translational shifts in the RA (rashift_error) and DEC (decshift_error) directions, together with the rotational error component, derived from from the catalogue that yields the 'best' solution, as follows: SYSERRCC = SQRT ( rashift_error² + decshift_error² + (r * thetarot_error)² ) where r is the radial off-axis angle of the detection from the spacecraft boresight in arcsecs and thetarot_error is the 1 σ error on the rotational correction (in radians). Where catcorr fails to obtain a statistically reliable result, SYSERRCC is 1.9 arcseconds (see Section 3 of the User guide or Webb et al. 2020 for more details). Note that rashift_error, decshift_error and thetarot_error are not provided separately in the catalogue.
REFCAT (I) SAS task catcorr: An integer code reflecting the absolute astrometric reference catalogue which gave the statistically 'best' result for the field rectification process (from which the corrections are taken). It is 1 for the SDSS (DR9) catalogue, 2 for 2MASS and 3 for USNO B1.0. Where catcorr fails to produce a reliable solution, REFCAT is a negative number, indicating the cause of the failure. The failure codes are -1 = Too few matches (< 10), -2 = poor fit (goodness of fit parameter in catcorr < 5.0), -3 = error on the field positional rectification correction is > 0.75 arcseconds) (see Sec. 3XMM-DR4 UG, Sec. 3.4). .
POSCOROK (B) SAS task catcorr: Signifies whether catcorr obtained a statistically reliable solution or not. This parameter is redundant in the sense that if REFCAT is positive, then a reliable solution was considered to have been found (see Sec. 3XMM-DR4 UG, Sec. 3.4). .
RA_UNC (D) [deg]SAS task emldetect: Right Ascension of the detection in degrees (J2000) as determined by the SAS task emldetect by fitting a detection simultaneously in all cameras and energy bands.
DEC_UNC (D) [deg]SAS task emldetect: Declination of the detection in degrees (J2000) as determined by the SAS task emldetect by fitting a detection simultaneously in all cameras and energy bands.
CCDPN (J)SAS task emldetect: pn CCD number on which the detection was made.
PN_RAWX (J)SAS task emldetect: Raw pixel position in the X direction of the pn detection.
PN_RAWY (J)SAS task emldetect: Raw pixel position in the Y direction of the pn detection.
CCDM1 (J)SAS task emldetect: MOS1 CCD number on which the detection was made.
M1_RAWX (J)SAS task emldetect: Raw pixel position in the X direction of the MOS1 detection.
M1_RAWY (J)SAS task emldetect: Raw pixel position in the X direction of the MOS1 detection.
CCDM2 (J)SAS task emldetect: MOS2 CCD number on which the detection was made.
M2_RAWX (J)SAS task emldetect: Raw pixel position in the X direction of the MOS2 detection.
M2_RAWY (J)SAS task emldetect: Raw pixel position in the X direction of the MOS2 detection.