# Presentation: 494879

## Presentation of the XMM-LSS project and 2003 results

*M. PIERRE and A. Refregier*
*CEA  Saclay*
*                   **Greenbelt**      Jan. 2004*

## 1. The   XMM-LSS

## XMM sensitivity

**125 A                            1.25A**

## XMM field of view  = 30 arcminPSF ~ 6”    

- Extragalactic fields ...

- XMDS Liege/Milan/Saclay

## Thanks to its-  unrivalled sensitivity-  large field of view-  good PSFXMM opens a new area for cluster LSS

## Next generation X-ray cluster LSS Survey

** **So far : the REFLEX sample  from the ROSAT All Sky Survey .   S = 3 10-12 erg/s/cm2                      *(Böhringer et al)*
- 	z  < 0.2
-  	=>  the cluster correlation function with ~ 450 clusters

-  Our goal : determine the cluster correlation function :
- 	in two redshift bins  		0 < z < 0.5     0.5 < z < 1
- 	each bin containing 450 clusters.

## The XMM-LSS Survey

- This has fixed the XMM-LSS survey characteristics:
**a 8x8 deg2 area covered by 10 ks XMM pointings****.**
-  sensitivity   5 10-15 erg/s/cm2 in the [0.5-2] keV band

## QSOs

**QSOs**

## GOAL

- Map the evolution of LSS of the universe out to z = 1
- with the galaxy cluster and QSO populations
- For the first time !

## Concept

- Optical ID
- Spectroscopic survey
**Cluster and QSO ******

**Weak lensing **
**    ****mass determination**

**XMM** observations

- Optical imaging with the **CFHT**** Legacy S****u****rvey**

**COSMOLOGY**

## A European/Chilean Consortium

- Birmingham
- Bristol
- Copenhagen
- Dublin
- ESO/ Santiago
- Leiden
- Liège

- Marseille (LAM)
- Milano (AOB)
- Milano (IFCTR)
- Munich (MPA)
- Paris (IAP)
- Santiago (Uni. Cato.)

**PI : ****Saclay, France**

## Expected number of clustersover a 8x8 sq.deg area

**~ 900 clusters    0 < z < 1   for ********CDM**
**~ 50  clusters    z > 1****  ?**

- Refregier et al 2004

## Cosmology with clusters 0<z<1

- Confidence levels: 68%, 90%, 95%

- Refregier, Valtchanov & Pierre 2001

- 8 / m

-  / m

**___**   clutser number density
- -----  cluster-cluster correlation fct.

## Cosmology with clusters 1<z<2

- Probability to find a Coma-type cluster in the XMM-LSS  (64 sq.deg.)
- within 1.5<z<2 :          6.5x10-7
- (CDM universe)

## Advanced follow-up : study clusters and AGNas a function of environment

- UKIDSS
- Radio VLA survey      *cluster environment - mergers*
- S-Z observations    (OCRA (2002) AMiBA (2004))
*	**	**	**	**	**	**  **low density structures*
- SIRTF Legacy associated survey in the MIR-FIR
- Galex

## Galex

**XMM Subaru Deep Survey**

- VVDS *wide*

**XMDS & VVDS deep**

**SIRFF Legacy : SWIRE**

-     NOAO Deep Survey

**Galex**

## 2. Results

## A piece of the XMM-LSS mosaic      

- A piece of the XMM-LSS mosaic

- 10 ks exp.       red [0.3-1] keV     green [1-2.5] keV    blue [2.5-10]keV

- Image by A. Read

## Source density

- At a sensitivity of  ~ 5E-15 erg/s/cm2
- in [0.5-2] keV  (current completeness limit)
- We find ~ 300 X-ray sources  per square degree

## Identification procedure

- cf multiple and redundant sources

## Example of simulations

## Slide 22

## Slide 23

## Slide 24

## Slide 25

## Slide 26

## Slide 27

## Slide 28

## 3 filtering

- 3 filtering

## 4 detection

- 4 detection

## CFH12k I-band 

- CFH12k I-band
- field size: 10'x10'
- a nearby candidate
- ~ 600 cts [0.5-5] keV

- pointlike sources

## CFH12k I-band 

- Nearby group

- (red sequence detection)
- z =  0.49 with 13 galaxies
- v = 460 km/s   => Lx_b =  1.7E43 erg/s,     measured: Lx_b< 6.2E42

-  Images: z' CTIO
- X-ray contours

## Ex: 1   VLT cluster :  z = 0.84

- The CD galaxy : 1h VLT/FORS2

## A relaxed medium cluster at z ~0.84

## A collapsinpg cluster at z ~ 0.77 

## Some AGNs in the same field

## A structure at z ~ 1

## A cluster at z = 1.05

** **
** **
**~ 560 cts [0.5-5] keV**

## Status of the identification process

## Spectroscopic ID summary 2002-2003

**2002**     21 XMM cluster candidates   spectroscopically observed (VLT et al)
- 20 confirmed
- Efficient method
- 1st sample of XMM serendipitous clusters
**2003**      50 cluster candidates observed with spectroscopy

## Two databases

- Milano : general catalogues
- X-ray, optical, radio
- Saclay : object-oriented cluster database
- Only validated multi- cluster information and redshifts

## Current assessment

- Current confirmed cluster sample : ~ 60-70 objects
- (depending on final spectroscopic reduction)
-  Our list of cluster candidates (Extended X with galaxy overdensity) is  larger than our initially predicted value of 15 /sq.deg.

## Theoretical considerations

- CDM model predicts at our sensitivity (~10-14erg/s/cm2), for 0<z<1:
-  12 /deg2 clusters with T> 2 keV
-  19 /deg2 clusters with T> 1.5 keV
- We are sensitive to a whole population of low-mass clusters
- First time seen at these redshifts
- Quite interesting!

## Perspectives for dark energy studies

## Further cosmological constraints

- w

- T*

- m

- 

- Priors for 8 from WMAP and
-  cluster scaling relations assumed
- Improvement over WMAP  on m by a factor of 2

- m and Ho fixed to WMAP values
- Prior form 8 assumed
- Determine T* and solve the controversy
- Constrain  (was taken to be 1 so far)

*.*

*Refregier et al 2004, in prep*