The XMM-Newton serendipitous survey IX. The fourth XMM-Newton serendipitous source catalogue

TL;DR

This paper presents the creation of the high-quality 4XMM-DR9 X-ray source catalogue from reprocessed XMM-Newton data, significantly improving detection quality and providing extensive data products for the astronomical community.

Contribution

The paper introduces a new, improved version of the XMM-Newton serendipitous source catalogue, 4XMM-DR9, with enhanced calibration, software, and data quality, covering over 800,000 detections.

Findings

Contains 810,795 detections with 550,124 unique sources

Provides spectra and lightcurves for over 288,000 bright sources

Detection quality has significantly improved over previous catalogues

Abstract

Sky surveys produce enormous quantities of data on extensive regions of the sky. The easiest way to access this information is through catalogues of standardised data products. {\em XMM-Newton} has been surveying the sky in the X-ray, ultra-violet, and optical bands for 20 years. The {\em XMM-Newton} Survey Science Centre has been producing standardised data products and catalogues to facilitate access to the serendipitous X-ray sky. Using improved calibration and enhanced software, we re-reduced all of the 14041 {\em XMM-Newton} X-ray observations, of which 11204 observations contained data with at least one detection and with these we created a new, high quality version of the {\em XMM-Newton} serendipitous source catalogue, 4XMM-DR9. 4XMM-DR9 contains 810795 detections down to a detection significance of 3 $\sigma$, of which 550124 are unique sources, which cover 1152 degrees$^{2}$ (2.85\%) of the sky. Filtering 4XMM-DR9 to retain only the cleanest sources with at least a 5 $\sigma$ detection significance leaves 433612 detections. Of these detections, 99.6\% have no pileup. Furthermore, 336 columns of information on each detection are provided, along with images. The quality of the source detection is shown to have improved significantly with respect to previous versions of the catalogues. Spectra and lightcurves are also made available for more than 288000 of the brightest sources (36\% of all detections).