The XMM Large Scale Structure Survey

Over the last two decades there has been tremendous growth in efforts to systematically map the matter distribution in the universe. This has been motivated by questions which are fundamental to cosmology. Firstly, how much matter is there; secondly, what form does it take; and thirdly, how is it distributed?

Taking advantage of the unrivaled sensitivity of the X-ray Multi mirror observatory (XMM-Newton), we have designed an XMM wide area survey with the aim of tracing the large scale structure (LSS) of the universe out to a redshift of z~1 as traced by clusters and quasars : the XMM-LSS Survey.  The survey consists of adjacent 10 ks MM

pointings, separated by 20'. It will ultimately cover a region of 8x8 sq.deg. to a mean sensitivity of about 5 10-15 erg/s/cm2 for point sources in the [0.5-2] keV band (with a deeper central 2 sq.deg. area). This makes the XMM-LSS some 1 000 times more sensitive than previous surveys and the only wide area X-ray deep survey for the

coming decade.  The X-ray survey is coupled with an extensive follow-up programme of radio, optical and IR observations.  As a result we will be able to identify clusters with unprecedented efficiency and reliability. In addition, our multi-wavelength observations of the XMM-LSS sources (clusters and quasars) will form the basis of a uniquely comprehensive study of the evolution of the structure of the universe from hundreds of Mpc down to galaxy scales. For the first time, it will be possible to map and study the

distributions of hot gas, luminous galaxies, and obscured or dark material in a coherent way. We will compare the results of our observations with the predictions of various cosmological scenarios using extensive numerical simulations generated as part of our

programme.

The wide scope of the project has motivated the set-up of a large consortium in order to carry out both the data reduction/management and the scientific analysis of the survey. The XMM-LSS Consortium comprises the following institutes: Saclay (Principal Investigator), Birmingham, Bristol, Copenhagen, Dublin, ESO/Santiago, Leiden, Liège,

Marseille (LAM), Milan (AOB), Milan (IFCTR), Munich (MPA), Munich (MPE), Paris (IAP), Santiago (PUC) as well as two US Scientists, S. Snowden (NASA/GSFC) and G. Bryan (MIT). The XMM-LSS team has also a well defined collaboration with the team carrying out the SIRTF Wide-area InfraRed Extragalactic Survey (PI, C. Lonsdale).

For further information:

http://vela.astro.ulg.ac.be/themes/spatial/xmm/LSS/index_e.html

8, 9 and 10 January 2002 the consortium that is carrying out the  XMM-LSS survey will meet at the Lorentz Center.

The plan of the meeting is as follows.  After a short presentation of the XMM status and standard data analysis/delivery, the first results from the XMM survey will be discussed.  Further items on the agenda include: (i) the status of the observing and funding proposals

submitted since last meeting, (ii) activities of the Working Groups and of the general organization (iii) planning of further XMM, optical and radio observation, (iv) collaboration with SIRTF survey SWIRE.

(v) meetings of the various working groups (X-ray analysis, Catalogue,

X-opt identifications,).