Related papers: The XXL Survey XXIV. The final detection pipeline
Context. The XMM-XXL survey uses observations from XMM-Newton to detect clusters of galaxies over a wide range in mass and redshift. The moderate PSF of XMM-Newton means that point sources within or projected onto a cluster may not be…
We use deep follow-up XMM-Newton observations of 6 clusters discovered in the XXL Survey at $z>1$ to gain robust measurements of their X-ray properties and to investigate the extent to which scaling relations at low redshift are valid at…
X-ray extragalactic surveys are ideal laboratories for the study of the evolution and clustering of active galactic nuclei (AGN). The XXL Survey spans two fields of a combined 50 $deg^2$ observed for more than 6Ms with XMM-Newton, occupying…
X-ray observations of galaxy clusters are impacted by the presence of active galactic nuclei (AGNs) in a manner that is challenging to quantify, leading to biases in the detection and measurement of cluster properties for both astrophysics…
We present the X-ray pipeline developed for the purpose of the cluster search in the XMM-LSS survey. It is based on a two-stage procedure via a dedicated handling of the Poisson nature of the signal: (1) source detection on multi-resolution…
Galaxy clusters trace the highest density peaks in the large-scale structure of the Universe. Their clustering provides a powerful probe that can be exploited in combination with cluster mass measurements to strengthen the cosmological…
This work is part of a series of studies focusing on the environment and the properties of the X-ray selected active galactic nuclei (AGN) population from the XXL survey. The present survey, given its large area, continuity, extensive…
Galaxy clusters appear as extended sources in XMM-Newton images, but not all extended sources are clusters. So, their proper classification requires visual inspection with optical images, which is a slow process with biases that are almost…
We present a large X-ray selected serendipitous cluster survey based on a novel joint analysis of archival Chandra and XMM-Newton data. The survey provides enough depth to reach clusters of flux of $\approx 10^{-14} {ergs} {cm}^{-2}…
The detection of clusters of galaxies in large surveys plays an important part in extragalactic astronomy, and particularly in cosmology, since cluster counts can give strong constraints on cosmological parameters. X-ray imaging is in…
In the currently debated context of using clusters of galaxies as cosmological probes, the need for well-defined cluster samples is critical. The XXL Survey has been specifically designed to provide a well characterised sample of some 500…
The XXL Survey is the largest homogeneous and contiguous survey carried out with XMM-Newton. Covering an area of 50 square degrees distributed over two fields, it primarily investigates the large-scale structures of the Universe using the…
The XXL survey currently covers two 25 sq. deg. patches with XMM observations of ~10ks. We summarise the scientific results associated with the first release of the XXL data set, that occurred mid 2016. We review several arguments for…
The detection of new clusters of galaxies or the study of known clusters of galaxies in X-rays can be complicated by the presence of X-ray point sources, the majority of which will be active galactic nuclei (AGN). This can be addressed by…
Context. The XXL Survey is the largest survey carried out by the XMM-Newton satellite and covers a total area of 50 square degrees distributed over two fields. It primarily aims at investigating the large-scale structures of the Universe…
Context. Distant galaxy clusters provide an effective laboratory in which to study galaxy evolution in dense environments and at early cosmic times. Aims. We aim to identify distant galaxy clusters as extended X-ray sources coincident with…
The discovery of fast and variable coherent signals in a handful of ultraluminous X-ray sources (ULXs) testifies to the presence of super-Eddington accreting neutron stars, and drastically changed the understanding of the ULX class. Our…
There is compelling evidence that AGNs are strongly influenced by their environment. Therefore, studying the AGN population of clusters is essential, as both large-scale structures and AGN play key roles in galaxy evolution, though the…
The study of the angular and spatial structure of the X-ray sky has been under investigation since the times of the Einstein X-ray Observatory. This topic has fascinated more than two generations of scientists and slowly unveiled an…
Inspired by the discovery of the Phoenix cluster by the South Pole Telescope team, we initiated a search for other massive clusters of galaxies missing from the standard X-ray catalogs. We began by identifying 25 cluster candidates not…