Enhanced XMM-Newton Spectral-fit Database

3XMM photo-z catalogue (XMMPZCAT)


  1. Catalogue overview
  2. Access to the photo-z catalogue

Catalogue overview

The XMM-Newton photo-z catalogue (XMMPZCAT) contains photometric redshifts for 42,696 X-ray sources in the 3XMM. This catalogue is produced through a machine learning algorithm (MLZ-TPZ) by using optical and IR photometry to derive phtometric redshifts. The version of the catalogue used to construct the current XMMPZCAT is 3XMM-DR6. Optical (SDSS-DR10) and IR data (2MASS, UKIDSS, All-WISE) is obtained from the multiwavelength cross-matched catalogues of the ARCHES project.

3XMM-DR6 is the third generation catalogue of serendipitous X-ray sources from the European Space Agency's (ESA) XMM-Newton observatory, and has been created by the XMM-Newton Survey Science Centre (SSC) on behalf of ESA. The 3XMM-DR6 catalogue contains photometric information for 678,680 source detections,corresponding to 468,440 unique sources.

The XMMPZCAT contains 3XMM sources outside the Galactic plane (|b|>20 deg) with highly reliable optical counterparts in the SDSS-DR10 catalogue. In this preliminary release of the catalogue we are presenting only objects with SDSS data. In the near future the catalogue will be expanded to include objects with counterparts in the Pan-STARRS catalogue, increasing the size of the XMMPZCAT by more than a factor two.

Access to the photo-z catalogue

The photometric redshift catalogue consists of a FITS table with one row for each unique X-ray source, and 17 columns containing the estimated redshift plus additional information about the X-ray source, the optical counterpart and several parameters that can help assessing the reliability of the derived photometric redshift (see a detailed description here). The table can be downloaded from the following link:

In addition, a supplementary FITS table is provided, containing the estimated probability density distribution for the photometric redshift of each source. The table can be downloaded from the following link: