1. X-RAY FOLLOW-UP OF STRONG LENSING OBJECTS: SL2S GROUPS (AND A1703) FABIO GASTALDELLO (IASF-MILAN, UCI) M. LIMOUSIN & THE SL2S COLLABORATION

2. OUTLINE INTRODUCTION TO GROUPS IN SL2S XMM SNAPSHOT PROGRAM FOR X-RAY FOLLOW-UP OF SL2S GROUPS: DETECTIONS AND PRELIMINARY INITIAL INFORMATION THE BULLET GROUP A1703

3. IMAGE SEPARATION DISTRIBUTION OF SL OGURI 2006 GALAXY GROUPS – POOR CLUSTERS WITH IMAGE SEPARATION IN THE RANGE 6”-16” HAVE BEEN SCARCELY REPORTED

4. IMAGE SEPARATION DISTRIBUTION OF SL OGURI 2006 NO 6”-15” IMAGE SEPARATION LENSES IN THE CLASS SURVEY (PHILLIPS+01, McKEAN10)

5. SL2S GROUPS INITIAL SAMPLE OF 13 OBJECTS, A SUBSAMPLE OF THE SL2S BASED ON MULTI-COLOUR CFHTLS, IDEAL TO DETECT SL FEATURES AND FOLLOW-UP HUBBLE IMAGING (z = 0.3-0.8) LUMINOSITY MAPS BASED ON LIGHT DISTRIBUTION OF ELLIPTICALS HAVE FOR SOME OBJECTS COMPLICATED SHAPE. WEAK LENSING SIGNAL DETECTED FOR 6 GROUPS

6. SL2S GROUPS

7. X-RAY FOLLOW-UP CLEARLY DIFFICULT BECAUSE WE ARE TARGETING LOW FLUX OBJECTS, HOWEVER MORE MASSIVE OBJECTS THAN PREVIOUS STUDIES (E.G., LARGEST IMAGE SEPARATION IN FASSNACHT+08 IS CLASS B2108+213 WITH R E = 2.5“) XMM SNAPSHOTS OF 5-10 ks TO SECURE FLUXES FOR DEEPER CHANDRA OBSERVATION. ENOUGH PHOTONS FOR MORPHOLOGY AND POSSIBLY TEMPERATURE

8. SL2SJ09013-0158 z = 0.30 (PHOT) STRAIGHT ARC BETWEEN THE TWO GALAXIES SL R E = 6.8“

9. SL2SJ09013-0158 TWO GROUPS DETECTED, THE N-ONE CONSISTENT WITH THE ELONGATION IN LUMINOSITY CONTOURS. THE S-ONE ASSOCIATED WITH THE LENS HAS A TEMPERATURE CONSISTENT WITH A POOR CLUSTER kT = 3.4 ± 0.6 keV

10. SL2SJ09013-0158 CLEARLY EXTENDED SOURCE (r c = 150 ± 60 kpc, 34” ± 13”, ß = 0.58 ± 0.12)

11. SL2SJ22214-0053 z = 0.334 STRAIGHT ARC BETWEEN THE TWO GALAXIES SL R E = 6.83±0.15“

12. SL2SJ22214-0053 JUST A POINT SOURCE DETECTED, HOWEVER VERY SHALLOW XMM EXPOSURE (5 KS)

13. SL2SJ09413-1100 z = 0.385 EXTENDED STELLAR HALO FOR CENTRAL GALAXY SL R E = 7.50±0.81“

14. SL2SJ09413-1100 RATHER REGULAR X-RAY EMISSION TEMPERATURE OF KT=3.6±0.4

15. SL2SJ09413-1100 CLEARLY EXTENDED SOURCE

16. SL2SJ02140-0532 z = 0.444 MULTIPLE IMAGES (SOUTHERN ARC MAYBE NOT ASSOCIATED) SL R E = 7.3“ ± 0.5”

17. SL+WL+GALAXY DYNAMICS (VERDUGO+11) UNIMODAL NFW W/ c_200 = 6.0±0.6 AND M_200 ≈ 1.0 x 10 14 REPRODUCES WELL ALL THE CONSTRAINTS

18. SL2SJ02140-0535 EVIDENCE FOR A SINGLE HALO: FIT A SINGLE HALO IN SL, NO OPTICAL SUBSTRUCTURE (MUNOZ+11, IN PREP) X-RAY EXTENDED BUT NOT ENOUGH COUNTS FOR SPECTRAL INFORMATION

19. SL2SJ08544-0053 z = 0.351 BIMODAL LUMINOSITY DISTRIBUTION (TWO DISTRINCT SUBGROUPS FROM SPECTROSCOPY WITH A VELOCITY DIFFERENCE OF 1200 km/s, MUNOZ+12, IN PREP.). PERTURBED LENSING CONFIGURATION WHICH REQUIRES EXTERNAL MASS (LIMOUSIN+10) SL R E = 5.5“ ± 0.1”

21. SL2SJ08544-0053 ELONGATED X-RAY EMISSION TEMPERATURE OF KT=2.7±0.4

22. SL2SJ08544-0053 CLEARLY EXTENDED SOURCE (r c = 128 ± 56 kpc, 26” ± 11”, ß = 0.52 ± 0.07)

23. SL2SJ08544-0053: THE BULLET GROUP SEPARATION BETWEEN X-RAY GAS AND GALAXIES

24. THE BULLET GROUP SEPARATION BETWEEN THE X-RAY PEAK AND THE GALAXY ASSOCIATED WITH THE LENS OF 22” (109 Kpc)

25. WHY LOOKING FOR BULLETS ?

26. Galaxies (5%) Intra-cluster medium (ICM) Thermal plasma X-rays (10-30%) Dark Matter Gravitational potential 1E 0657-156 THE BULLET CLUSTER MARKEVITCH+04

27. CONSTRAINTS ON DM SELF- INTERACTION CROSS SECTION RANDALL+08

28. BABY BULLET (MACS J0025) BRADAČ+08

29. SHAN+10 SL2S J08544

30. ABELL 1703 LIMOUSIN+08 RICHARD+09

31. ABELL 1703 RICHARD+09 UNIMODAL REGULAR CLUSTER

32. ABELL 1703

34. TEMPERATURE OF KT=7.9±1.2 keV

35. SUMMARY SL2S IS FINALLY PROVIDING A GOOD SAMPLE OF LENSING GROUPS/POOR CLUSTERS, OPENING A NEW WINDOW OF THE MASS SPECTRUM FOR LENSING/X-RAY COMPARISON STAY TUNED FOR MORE TARGETS AND MORE DATA: THE GOAL IS TO OBTAIN CHANDRA OBSERVATIONS TO ALLOW X-RAY HE MASS RECONSTRUCTION, AS DONE FOR LOCAL (z < 0.1) GROUPS (GASTALDELLO+07) THE BULLET GROUP IS THE FIRST GROUP MASS-SIZE EXAMPLE OF A BULLET AND A GOOOD PROMISE FOR A STATISTICAL DETECTION OF BULLETICITY (Massey+11) A1703 IS REALLY AN EXCEPTIONAL TARGET AND WE HOPE TO GET BETTER X-RAY DATA WITH CHANDRA

36. SL2SJ02254-0737 z = 0.511 RADIO SOURCE COINCIDENT WITH CENTRAL GALAXY SL R E = 6.0“ ± 0.3”

37. SL2SJ08591-0345 z = 0.647 VERY EXOTIC SL CONFIGURATION, DIFFICULT TO KNOW HOW MANY MULTIPLE IMAGES ARE OBSERVED SL R E = 8“

38. IMAGE SEPARATION OF SL Fraction of lensing by satellites peaks at 1” and decreases rapidly with increasing image separation 14% and 4 percent of lenses in groups and clusters, half of them expected to be by satellites Separation enhanced significantly by surrounding haloes OGURI 2006