The first task of the ARCHES project is to select in the 3XMM-Newton catalogues the most reliable and "cleanest" X-ray sources, thus enhancing its quality and usability and, in parallel to this, to perform a review of the currently available archival catalogues in order to select the most scientifically relevant ones to be used in the cross-correlations process. This concerns two WPs.

WP3 - Enhancing the 3 XMM-Newton Catalogues

WP7 – Reviewing and selecting the best quality catalogues

• Enhancing the 3 XMM-Newton Catalogue (WP3)

WP3 aims at producing an enhanced, value-added version of the XMM Newton Serendipitous Source Catalogue.

Data quality has been characterised and flagged appropriately in order to address the completeness and reliability of the XMM-Newton catalogue. Selecting the best quality sources and identifying their relevance in the context of the various investigated science cases has very significantly enhanced the usability of the XMM-Newton catalogue for astrophysical research.

Planned activity and outcome at the start of the project:

The University of Leicester which has long been responsible for the XMM Catalogue activities is leading this WP and is in charge of the development of scripts, the production of the enhanced version and is also leading the reliability/completeness assessment task.

Other ARCHES partners, the University of Strasbourg, the Astrophysik Institute Potsdam and the University of Cantabria, are contributing to this WP by taking part in the definition of activities, in the testing, validation and documentation as well as in the reliability/completeness assessment.

The output achieved:

-A version of the 3 XMM catalogue cleaned of dubious or low scientific value entries and enriched with additional parameters. The enhanced catalogue was released together with a documentation describing its statistical properties in terms of covered areas, completeness and depth

• Reviewing and selecting the most suitable archival catalogues (WP7)

WP7 aims at selecting the best set of existing archival astronomical catalogues to be cross-correlated with the XMM source catalogue, with the ultimate goal of maximizing the coverage, quality and scientific usefulness of the spectral energy distributions (SEDs) produced as a result of those cross-correlations.

Planned activity and output at the start of the project:

This WP has planned an exhaustive review of the currently available archival catalogues. Selection criteria include: accessibility and availability of documentation (meta data), photometric and astrometric quality, sky coverage, compatibility of angular resolution with that of the XMM catalogue, expertise within the team. After the development of the cross-correlation and SED-building tools, some adjustments to the list might be necessary to optimise the results.

This WP is under the responsibility of University of Cantabria however all partners have contributed to the outcome :

-A documented list of catalogues suitable for cross-correlation and SED-building, including summary information on sky coverage, photometric and astrometric accuracy, spectral band(s) and links to data.