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 100,178 X-ray sources in the 3XMM. This catalogue was produced through a machine learning algorithm (MLZ-TPZ) by using optical and IR photometry to derive photometric redshifts. The version of the catalogue used to construct the current XMMPZCAT is 3XMM-DR6. Optical (SDSS, Pan-STARRS) and IR data (2MASS, UKIDSS, VISTA, All-WISE) were obtained from multiwavelength cross-matched catalogues using tools and results from 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, covering a sky area of ~1000 square degrees.

XMMPZCAT contains 3XMM sources outside the Galactic plane (|b|>20 deg) with highly reliable optical counterparts in the SDSS-DR13 or Pan-STARRS-DR1 catalogues. It offers photo-z for about 50% of the X-ray sources within the selected XMM-Newton observations to build the catalogue.

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, its corresponding 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: