Identification of the source (10 columns)

DETID (J)

A consecutive number which identifies each entry (detection) in the catalogue.

SRCID (J)

A unique number assigned to a group of catalogue entries which are assumed to be the same source. To identify members of the same group the distance in arcseconds between each pair of sources was compared on the three-sigma level of both positional errors. A maximum distance of 7" was assumed, which was reduced to 0.9 * DIST_NN (distance to the nearest neighbour) where necessary. See 2XMM UG, Sec. 3.2.3 a) and 2XMMi UG, Sec. 3.2.1  for a more detailed description.

SRCID_2XMM (J)

The unique source ID of the detection, DETID, in the 2XMM catalogue. Due to the nature of the matching algorithm, some detections were re-assigned to a different source due to the presence of new detections, see 2XMMi UG, Sec. 3.2  for a more detailed description.

This column is new in 2XMMi.


IAUNAME (21A)

The IAU name assigned to the unique SRCID (see 2XMMi UG, Sec. 3.2.3 ).

SRC_NUM (J) SAS task srcmatch


The (decimal) source number in the individual source list for this observation; in the hexadecimal system it identifies the source-specific product files belonging to this detection (Appendix A.1).

MATCH_1XMM (21A)

The IAU name of the 1XMM source ID matched within radius of 3" and using the closest candidate, see 2XMM UG, Sec. 3.2.5.

SEP_1XMM (E) [arcsec]

The distance between this source and the matched 1XMM source (MATCH_1XMM) in arcseconds.

SRCID_2XMMP (J)

The source ID of the 2XMMp unique source matched within radius of 3" and using the closest candidate, see 2XMM UG, Sec. 3.2.5.

This column was not given in 2XMMp.


MATCH_2XMMP (22A)

The IAU name of the 2XMMp source ID matched within radius of 3" and using the closest candidate, see 2XMM UG, Sec. 3.2.5.

This column was not given in 2XMMp.


SEP_2XMMP (E) [arcsec]

The distance between this source and the matched 2XMMp source (MATCH_2XMMp) in arcseconds.

This column was not given in 2XMMp.