Welcome on XXL Information System

The information system design and implementation is developped at LAM (Marseille) by the CeSAM; quality processes are included in the development. It is develope d under the SItools middleware interface.

Survey Description

The XMM-LSS Survey is one of the largest deep cluster survey to date. Extensive coverage exists from X-ray to radio
wavelengths over the 11 deg2 area. The survey enables the detection of clusters (M~1014Mo) well above z>1. Special care
has been devoted to the characterization of the survey selection function and, to date, the XMM-LSS cluster sample is the
only published sample of XMM serendipitous clusters with well-modelled selection criteria.

The XXL survey will map two extragalactic regions of 25 deg2, using 10 ks XMM observations to yield a point-source sensitivity of ~ 5 10-15 erg/s/cm2 in the [0.5-2] keV band.

It is the largest XMM project approved to date (3Ms in December 2010, >6Ms in total).
Some 600 new galaxy clusters are expected out to z~1.5-2 as well as more than 10,000 active galactic nucleus (AGNs) out to z~4.
The main goal of the project is to constrain the Dark Energy equation of state using clusters of galaxies. This survey will also have lasting legacy value for cluster scaling laws and studies of AGNs and X-ray background.
This project builds on the experience acquired during the ten years XMM-LSS pilot survey. It is open to any scientist belonging to the international astronomical community, and interested in actively contributing to the general legacy effort.
The two surveyed regions are:

  • CFHTLS W1 centre: 2h23min    -4deg30' (J2000),  25 deg2
  • BCS centre: 23h30min  -55deg00' (J2000)

X-Ray Observations start by mid 2011 and are since completed by mid 2013