Thermo- and chemo-dynamics of the ICM with simulations Stefano Borgani Dept. of Physics - University of Trieste INAF Astronomical Observatory of Trieste I. Chemical enrichment of the ICM I.a Effect of feedback on cluster cores I.b Effect of feedback on cluster outskirts I.c Outskirts as fossil records of past feedback history II. Proto-clusters II.a Why important at z~2-3? II.b What do we expect to see in X-rays? Talk @ SnowCluster, Snowbird (Utah), 18-23 March 2018
Collaborators: Veronica Biffi (Univ. Trieste, Italy) Klaus Dolag (LMU, Munich, Germany) Dunja Fabjan (Univ. Ljubljana, Slovenia) Massimo Gaspari (Princeton Univ., USA) Gianluigi Granato (INAF, Trieste, Italy) Giuseppe Murante (INAF, Trieste, Italy) NhutTruong (Eötvös University, Budapest, Hungary) Susana Planelles (Univ. Valencia, Spain) Cinthia Ragone-Figueroa (IATE, Cordoba, Argentina) Elena Rasia (INAF, Trieste, Italy) Alex Saro (INAF, Trieste, Italy) Giuliano Taffoni (INAF, Trieste, Italy) Luca Tornatore (INAF, Trieste, Italy)
A set of simulated clusters 140 halos with M vir >5 x 10 13 h -1 M Hydro (Beck+15): Gadget-3 SPH + Higher-order kernel Wake-up scheme for time-step of gas particles Time-dependent artificial viscosity Artificial conduction Astrophysics: Cooling + SF + SN feedback (Springel & Hernquist 03) Chemical enrichment (Tornatore+07) AGN feedback (Steinborn+15) Bonafede+12
Brightest Cluster Galaxies Ragone-Figueroa+18 MBH-M* relation to calibrate feedback parameters Observations from McConnell & Ma (2013) M*BCG-M500 close to observations (Kravtsov+14). and lower than in other simulations (Hydrangea-EAGLE and ILLUSTRIS) Total stellar mass also close to observations (Gonzalez+13, Kravtsov+14)
Part I: Chemical enrichment of the ICM
Cool-coreness & chemical enrichment Biffi+17 Pseudo-entropy Metallicity Pseudo-entropy Metallicity No CC/NCC diversity w/out AGN feedback AGN feedback: lowercore entropy higher level of enrichment AGN feedback: more widespread enrichment in the outskirts
Temperature dependence of ICM enrichment Truong+18 See talk by N. Truong CC clusters slightly more enriched than NCC In better agreementwith CHEERS data Enrichment independentof temperature (for T>1 kev)
Cool-coreness & chemical enrichment NCC Rasia+15 Ettori+2015: XMM-Newton observations of 83 clusters at z~0.1-1.4 Increase of metallicity in core regions less pronounced in NCC systems CC Trend reproduced by simulations Result of mixing of enriched gas during the mergers destroying the CC structure
Cool-coreness & chemical enrichment Biffi+17 Leccardi+10: XMM-archival study of correlation betweenpseudo-entropy ratio and central metallicity W/out AGN feedback: No (or few spurious) CC clusters Too high enrichment in core regions With AGN feedback: Correct CC-NCC diversity Observed entropy-metallicity relation reproduced
AGN feedback & enrichment Planelles+13 Change the pattern of chemical enrichment in galaxy clusters (e.g. Fabjan+10, McCarthy+10, Planelles+13) Effect of AGN: Metal enriched gas expelled from SF-regions More widespread enrichment Shallower Z-profiles Overall good agreement with data
Enrichment out to large radii Urban+17 Suzaku observations of 10 nearby galaxy clusters Measurement of Fe abundance out to >0.5r 200 Constant enrichment level in the outskirts at 0.3 Z Witnessing an early epoch of enrichment, before the formation of clusters
AGN feedback & enrichment Biffi+18 Already available data (Urban+17) tend to prefer AGN-driven enrichment pattern. Q: to what extent Athena s and Lynx s sensitivity will allowto discriminate btwn different enrichment (i.e. feedback) histories?
Evolution of metallicity Simulations Biffi+17 IN: r < 0.05 R 180 OUT: 0.05 R 180 < r < 0.2 R 180 No much evolution of the metallicity in different regions out to z=2 Ettori+15 Observations Ettori+15 ; McDonald+16: No evolution of metallicity outside core regions But, some negative evolution in core regions Driven by CC clusters Too poor statistics of high-z CC clusters in our simulations
Enrichment & star formation history Biffi+17 Effect of AGN feedback: Regulate SF since z=5 Expel metals outside galaxies Overall diffuse preenrichment Higher metallicity in cluster outskirts at low redshift
Tracking the enrichment history Q: where metals in the outskirts are coming from? Biffi+18 Tracking back in time metal-enriched particles found at z=0 in cluster outskirts [0.75-1]R 200 Most of tracked NO AGN enriched particles residing in the diffuse medium at z=2 Already enriched and expelled from starforming galaxies Clumpy enrichment in the absence of AGN feedback
Part II: Proto-clusters
Star formation in z~2 clusters 300 kpc 150 kpc The Spiderweb Complex (z=2.12; Miley+06) Hatch+08: UV from HST-ACS: SFR >325 M yr 1 (44% contributed by IGL) Seymour+12: Spitzer + Herschel + LABOCA: SFR = 1400 M yr 1 Hatch+09
Simulating the formation of a protocluster at z~2 Saro+2008 C2 - AGN C2 - Winds SN-driven winds: SFR ~ 1750 M yr 1 (19% from IGL) AGN feedback: SFR ~ 1300 M yr 1 (55% from IGL)
Simulating the formation of a protocluster at z~2 C1: M 200 (z=0)=1.6 10 14 h -1 M Saro+2008 z=2.12 Gas density L 0.5-2 = 3.6 10 43 erg s -1 T X =1.7 kev Z Fe = 0.37 Z sun C2: M 200 (z=0)=1.5 10 15 h -1 M Winds: L 0.5-2 = 4.1 10 44 erg s -1 T X =4.7 kev Z Fe = 0.45 Z AGN: L 0.5-2 = 1.4 10 44 erg s -1 T X =3.8 kev Z Fe = 0.57 Z
How should Chandra see it? X-ray Chandra isophotes and VLA 1.4 GHz continuoum (Carilli+02) SN only SN + AGN 35 ksec Chandra ACIS-S exposure Possible thermal emission from shocked gas Only upper limits on emission from hydrostatic ICM 500 ks with ACIS-S: Counts [0.5-7] kev band ~ 3800 for SN only ~ 1000 for SN+AGN First secure detection of thermal ICM at z~2; Measure temperature and metallicity
Conclusions & directions Current generation of cosmological simulations provide a realistic description of ICM thermo- and chemo-dynamical properties (see talks by K. Dolag, D. Nagai, A. Pillepich, D.Barnes) Reliable to make predictions of X-ray observables in (almost) unexplored regimes ICM in cluster outskirts as fossil record of past history of feedback: star formation, metal production and circulation, AGN feedback Observations of proto-clusters to catch these processes in the act Ideal targets for Athena and Lynx Angular resolution and background as a critical issues