1. On the evolution of Cool Core Clusters Joana Santos (INAF-Trieste) Piero Rosati (ESO), Paolo Tozzi (INAF-Trieste), Hans Boehringer (MPE), Stefano Ettori (INAF-Bologna) IBERICOS09, Madrid, April 2009

2. 16 April 2009Joana Santos (INAF-Trieste) IBERICOS092 Introduction Clusters of galaxies: Largest gravitationally bound systems in the Universe, dominated by DM, formed at z>2 Baryon content: hot gas (intracluster medium) + galaxies Cosmological probes Ideal astro labs to study complex physics of baryons Cool Core Clusters (CCC) Highly relaxed galaxy clusters show central radiative cooling Core temperature: T core ~ 1/3 T avg Central Surface Brightness (SB) excess Cooling time, t cool shorter than Hubble Time

3. 16 April 2009Joana Santos (INAF-Trieste) IBERICOS093 Motivation Why are CCC important? Cooling Flow problem: cool cores are not too cold! likely heating mechanisms: AGN feedback + mergers CCC affect scaling relations – connection to cluster mass Cosmology using galaxy clusters: cluster detection Current knowledge on CC abundance Local Universe: 50 - 70% Peres et al. 98, Mittal et al. 08 Since z=0.4: No evolution Bauer et al. 05 0.5 Lack of cool cores?... Vikhlinin et al. 06 Beyond z=1 ?... Study population of CCC @ 0.7 < z < 1.4 using high resolution CHANDRA images J.S.Santos et al. A&A 2008

4. 16 April 2009Joana Santos (INAF-Trieste) IBERICOS094 Data CHANDRA archive Low-z sample: 11 clusters, 0.15 < z < 0.3 selection: >10000 cts, T > 5 keV heterogeneous sample Strong CC (control sample) Moderate CC Non CC High-z sample: 15 clusters, 0.7 < z < 1.4 representative sample Rosati et al. 98

5. 16 April 2009Joana Santos (INAF-Trieste) IBERICOS09 Low redshift cluster sample 8”

6. 16 April 2009Joana Santos (INAF-Trieste) IBERICOS09 High redshift cluster sample 3”

7. 16 April 2009Joana Santos (INAF-Trieste) IBERICOS097 Surface Brightness fitting at high-z: single & double β models β model: S (cts/s/pix) Cavaliere & Fusco-Femiano 76 1 β model: non-CC 2 β model: CC

8. 16 April 2009Joana Santos (INAF-Trieste) IBERICOS098 N Surface Brightness Concentration, C SB NCCCC

9. 16 April 2009Joana Santos (INAF-Trieste) IBERICOS099 Simulating clusters by cloning Assumption: no intrinsic cluster evolution Low redshift X-ray images (parameter free) Flux rescale: Luminosity distance, D L + K-correction (z,T) Spatial rescale (angular distance, D A ) Chandra PSF ~ 1” -> Res = 8 kpc @ z=1 -> no PSF deconvolution Cloning @ work:

10. 16 April 2009Joana Santos (INAF-Trieste) IBERICOS0910 N Surface Brightness Concentration, C SB Clones recover same C SB of parent sample -> no z-dependence NCCCC

11. 16 April 2009Joana Santos (INAF-Trieste) IBERICOS0911 Scaled SB profiles 3 bins of C SB : C SB > 0.155 0.075< C SB < 0.155 C SB < 0.075 Self Similar Scaling Law: LOW-z Strong CC Mod CC - - - NCC HIGH-z Mod CC - - - NCC Arnaud et al 2005

12. 16 April 2009Joana Santos (INAF-Trieste) IBERICOS0912 Central Cooling Time, t cool 10 high-z cl t cool < 10 Peterson & Fabian 2006

13. 16 April 2009Joana Santos (INAF-Trieste) IBERICOS0913 Correlation t cool - C SB

14. 16 April 2009Joana Santos (INAF-Trieste) IBERICOS0914 Conclusions Surface Brightness analysis: C SB + stacked SB profiles indicate a significant fraction of moderate CC @ 0.7< z<1.4 Absence of pronounced CC at high-z Cooling time supports SB results: 10/15 clusters t cool < Hubble time ( makes sense: distant galaxy clusters are dynamically younger …) -> hint for evolution? Future work: (X-ray) independent measurement Is there cold gas? How much? -> Search for optical emission (Hα) ESO/SINFONI NIR spectroscopy of XMMUJ2235 @ z=1.4 (PI J.Santos)

15. 16 April 2009Joana Santos (INAF-Trieste) IBERICOS0915 WFXT – Wide Field X-ray Telescope PI: Riccardo Giacconi – ASTRO2010 DECADAL SURVEY

16. 16 April 2009Joana Santos (INAF-Trieste) IBERICOS09 High Redshift sample RXJ1113V1221RXJ2302MS1137 RXJ1317RXJ1350RXJ1716MS1054 RXJ1226CLJ1415RXJ0910 RXJ1252 RXJ0849RXJ0848XMMU J2235 ` C SB > 0.095 0.075 < C SB < 0.095 `` ` ` ``