# Presentation: 608985

##  Talk @ “The Warm & Hot Universe”, New York, May 7th-9th 2008

-  **Talk**** @ ****“The Warm & Hot Universe”, New York, May 7****th****-9****th**** ****200****8**

-   (I) X-ray scaling relations & ICM thermodynamics;
-  (II) Including chemical evolution in simulations:
-       II.a Metal Enrichment of the ICM;
-       II.b Optical/near-IR properties of the galaxies.
- (III) The effect of AGN feedback.
- Collaborators: K. Dolag, S. Ettori, D. Fabjan, G. Murante, E. Rasia, A. Saro, L. Tornatore

## Different strategies to simulate clusters

- _SB et al. ‘08_
- L= 75 h-1 Mpc
- Ngas=NDM=5123
- Pl = 2.1 h-1 kpc
- SF + SN + metals

**Different strategies to simulate clusters**

- _Dolag et al. ‘07_
- M ~ 2 1015 h-1 M****
- Ngas=NDM~ 107
- Pl = 2.5 h-1 kpc
- SF + SN + metals

- SB, Dolag et al. 08; Dolag, SB et al. 08,      for reviews

## The mass-temperature relation

**The mass-temperature relation**

- True masses

- Recovered masses

- SB et al. 04            Rasia et al. ‘05
- Use the -model for the ICM + hydrostatic equilibrium: (Finoguenov et al. ’01; Ettori et al. ’03)

- Nagai et al. ‘07
- Carry out the same mass estimates as in Chandra data
- (Vikhlinin et al. ‘05)

- Good agreement between simulated and observed M-T, once hydrostatic mass estimates used in simulations.

## The Luminosity-Temperature  relation

**The Luminosity-Temperature  relation**

- ___è ‘02:_ cooling only
- LX-T relation reasonable, but up to 80% of baryons in stars for groups!

- _Muanwong et al‘03:_ cooling + pre-heating
- No much bending at the scale of groups.

- _SB et al‘04:_ cooling + SF + galactic winds
****~ OK above 2 keV
****Over-luminous groups and too small scatter.

- SB et al. ‘04

## The Temperature Profiles

**The Temperature Profiles**

- Tornatore et al. ‘03; SB‘04; Roncarelli et al. ‘07; Kay et al. ‘07: cooling + SF + galactic winds (SPH);

- Loken et al. ‘02; Nagai‘07: cooling + SF + SN feedback (AMR):
**** Cooling steepens T-profiles at the centre;
****Wrong in the core regions
****OK at larger radii.

- Nagai et al. ‘07

- Leccardi & Molendi 08

- SB et al. ‘04

- Pratt et al. ‘07; Leccardi & Molendi ‘08: analysis of XMM data.
- Agreement with simulations outside the cool core region.

## Hydro simulations of the ICM enrichment

- Implementation in the GADGET-2 code (Springel ‘05)
- _Model parameters:_
- (a) IMF; a.1 Power-law IMF: (m) ~ m -(1+x)  x=1.35: Salpeter 55; x=0.95:
-                      Arimoto Yoshii 89
-               a.2 Multi-slope IMF (Kroupa 01)
- (b) Stellar lifetimes: Padovani & Matteucci ’93; Maeder & Meynet ‘89
- (c) Metallicity-dependent stellar yields (SN-Ia, SN-II and AGB)
- (d) Velocity of galactic winds:  vw=500 km s-1 (normal winds)
-                                                  vw=1000 km s-1 (strong winds; AY IMF)
- _Simulated clusters_: 9 Lagrangian regions (Dolag et al. ‘08) containing 19 “clean” clusters with Mvir = (5x1013 - 2x1015 h-1Msun)

**Hydro simulations of the ICM enrichment**
-  Tornatore et al. ‘04, ’07; Fabjan et al.’08
-  SB, Fabjan, Tornatore et al. ‘08 for a review

## Maps of Iron distribution

**Maps of Iron distribution**

- Salpeter IMF

- Top-heavy IMF

- Tornatore et al. ‘07

## Mock X-ray observations of ICM metallicity

- Rasia et al. 2007

- 1 Ms exposure of a       ~8 keV cluster
**** EW and spect.  estimators of ZFe and ZSi quite close to each other (unlike Tew and Tspec).

**** Spect. measurement overestimates ZO:
****Due to the multi-component nature of the ICM.
****Bias related to the limited XMM spectral resolution.

## Profiles of Iron Abundance

**Profiles of Iron Abundance**

- Vikhlinin et al. ‘05: Chandra observations of 16 nearby relaxed clusters
- 1. Agreement with the slope from Chandra data.
- 2. Preference for a standard Salpeter IMF
- 3. Flattening at >0.1R500 (XMM: Snowden et al. 07) never predicted
********Highly desirable: comparison btw Chandra & XMM results.

- Fabjan et al. ‘08

## Evolution of the ICM metallicity

**Evolution of the ICM metallicity**

- Observational data from Chandra archive:        Balestra et al. ‘07               Maughan et al. ‘08

****Metallicity evolution naturally produced.
****Test: halt by hand SF at z=1.
**** Metals produced at lower z by long-lived stars
**** Far too strong metallicity evolution
**** Need residual low-z SF to “eat” metals in high-density regions.

## Evolution of the ICM metallicity

**Evolution of the ICM metallicity**

- Reference run

- SF & metals stopped at z=1

- SF stopped at z=1

## The Sn-Ia rate

**The Sn-Ia rate**

- _Observational data:_
- z ~ 0: Mannucci et al. 07
- z ~ 1.2: Sharon et al. 07
- z ~ 0.2-0.9: Gal-Yam et al. 07
- Salpeter IMF favoured by low-z data
- Too high low-z rate from excess of recent SF
- Better agreement if SF quenched at z<1.

- Rate of Sn-Ia per unit B-band luminosity

**Notes:**
Newer plot from Dunja

## The Color-Magnitude Diagram

**The Color-Magnitude Diagram**

- Bower et al.’92

- 1. The CMR is given by a metallicity sequence.
- 2. Closer to the observed relation for a Salpeter IMF
- 3. BCGs always much bluer than expected
-  Too much ongoing star formation in the BCGs
-  Need to quench SF at z<1.

- Saro et al. ‘06

## Feedback from BH accretion in GADGET

**Feedback from BH accretion in GADGET**

- Springel, Di Matteo & Hernquist (2005).
****Bondi accretion rate (related to the large-scale properties of the gas distribution), with Eddington limit:

- : radiative efficiency

- : thermalized energy

****Seed BHs with initial mass of 105 M
****BHs accrete mass by swallowing of gas particles and merging.

## The effect of AGN feedback

**The effect of AGN feedback**

- Sijacki et al. ‘07

-  ”Self-consistent” BH feedback”
-  “QSO mode”: low-efficiency thermal feedback
-  “Radio mode”: energy in inflating bubbles.
- (see talk by E. Puchwein)

## The effect of the BH feedback

**The effect of the BH feedback**

- • Couple the BH feedback by Springel et al. ‘05 with the metal enrichment scheme.
-  Quench star formation at z<3
-  Suppression of the temperature spike;
-  Increase of the central entropy;
-  Flattening of the metallicity profiles for R>0.2R200.

- 1014h-1Msun

- 1015h-1Msun

- De Grandi & Molendi ‘02

- Fabjan et al. ‘08

## Producing the “cool core” structure

**Producing the “cool core” structure**

## AGN feedback: phase diagram

**AGN feedback: phase diagram**

- Mvir = 1.0 x1014 h-1 Msun
- Gas within 0.2 Rvir
-  Simulations naturally predict the lack of gas at T<0.5 Tvir
-  Galactic winds: bring gas on a lower adiabat;
- Negative T-profiles still present
-  AGN feedback: strong suppression of central density
- ~ no trend of gas with T.

## The effect of the BH feedback

**The effect of the BH feedback**

- Effect on the CMR:
- • Make it bluer, due to lower metallicity of galaxies;
- • BCGs older but still blue, due to a lower metallicity.

- No winds
- No AGN

- Winds
- No AGN

- No Winds
- AGN

- Need to model the transition from the QSO to the “radio” mode: more efficient to quench SF in BCGs!

## Conclusions

- (a) Simulations are doing remarkably well outside cool-cores.
- (b) Inner temperature profiles & BCG colors  wrong cool cores.
- (c) Profiles and evolution of ZFe  nearly OK.
-        Shall we trust them until we have the right galaxies?
- (d) Suppress low-z star formation: required by the CMR and by the Sn-Ia rate.
-       Need to be gentle  Prevent too strong metallicity evolution.
- (e) AGN feedback goes in the right direction. BUT:
-       Need to better understand cross-talk between widely      different (~1 pc vs. >100 kpc) scales;
-       Relative importance of different channels for energy thermalization.