MASS AND ENTROPY PROFILES MASS AND ENTROPY PROFILES OF X-RAY BRIGHT RELAXED OF X-RAY BRIGHT RELAXED

GROUPS GROUPS

FABIO GASTALDELLO

UC IRVINE & BOLOGNAD. BUOTE

P. HUMPHREY

L. ZAPPACOSTA

J. BULLOCK

W. MATHEWS UCSC

F. BRIGHENTI BOLOGNA

OUTLINEOUTLINE

1. MASS RESULTS AND c-M PLOT FOR X-RAY GROUPS

2. ENTROPY PROFILES

3. FOCUS ON SOME PARTICULAR OBJECTS

DM DENSITY PROFILEDM DENSITY PROFILE

Navarro et al. 2004

The concentration parameter c do not depend strongly on the innermost data points, r < 0.05 rvir (Bullock et al. 2001, B01; Dolag et al. 2004, D04).

c-M RELATIONc-M RELATION

Bullock et al. 2001

•c slowly declines as M increases (slope of -0.1)

•Constant scatter (σlogc ≈ 0.14)

•the normalization depends sensitively on the cosmological parameters, in particular σ8 and w (D04,Kuhlen et al. 2005).

Concentrations for relaxed halos are larger by 10% compared to the whole population (Jing 2000, Wechsler 2002, Maccio’ 2006). They show also smaller scatter (σlogc ≈ 0.10)

Wechsler et al. 2002

Selection EffectsSelection Effects

A SPECIAL ERA IN X-RAY ASTRONOMY

Chandra XMM-Newton

•1 arcsec resolution •High sensitivity due to high effective area, i.e. more photons

• NFW a good fit to the mass profile

•c-M relation is consistent with no variation in c and with the gentle decline with increasing M expected from CDM (α = -0.040.03, P05).

Vikhlinin et al. 2006Pointecouteau et al. 2005

Clusters X-ray resultsClusters X-ray results

THE PROJECTTHE PROJECT

•Improve significantly the constraints on the c-M relation by analyzing a wider mass range with many more systems, in particular obtaining accurate mass constraints on relaxed systems with 1012 ≤ M ≤ 1014 Msun

•There are very few constraints on groups scale (1013 ≤ M ≤ 1014 Msun) , where numerical predictions are more accurate because a large number of halo can be simulated.

In Gastaldello et al. 2007 we selected a sample of 16 objects in the 1-3 keV range from the XMM and Chandra archives with the best available data with

•no obvious disturbance in surface brightness at large scale

•with a dominant elliptical galaxy at the center

•with a cool core

•with a Fe gradient

The best we can do to ensure hydrostatic equilibrium and recover mass from X-rays.

SELECTION OF THE SAMPLESELECTION OF THE SAMPLE

RESULTSRESULTS•After accounting for the mass of the hot gas, NFW + stars is the best fit model

MKW 4

NGC 533

RESULTSRESULTS•No detection of stellar mass due to poor sampling in the inner 20 kpc or localized AGN disturbance

NGC 5044

Buote et al. 2002

RESULTSRESULTS

•NFW + stars best fit model

•We failed to detect stellar mass in all objects, due to poor sampling in the inner 20 kpc or localized AGN disturbance. Stellar M/L in K band for the objects with best available data is 0.570.21, in reasonable agreement with SP synthesis models (≈ 1)

•Adopting more complicated models, like introducing AC or N04 did not improve the fits. AC produces too low stellar mass-to-light ratios

c-M relation for groupsc-M relation for groups

We obtain a slope α=-0.2260.076, c decreases with M at the 3σ level

THE X-RAY c-M RELATION THE X-RAY c-M RELATION • Buote et al. 2007 c-M relation for 39

systems ranging in mass from ellipticals to the most massive galaxy clusters (0.06-20) x 1014 Msun.

• A power law fit requires at high significance (6.6σ) that c decreases with increasing M

• Normalization and scatter consistent with relaxed objects

THE X-RAY c-M RELATION THE X-RAY c-M RELATION

WMAP 1 yr Spergel et al. 2003

THE X-RAY c-M RELATION THE X-RAY c-M RELATION

WMAP 3yr Spergel et al. 2006

CLUSTERS PREFER HIGH CLUSTERS PREFER HIGH σσ88

Evrard et al. 2007

CLUSTERS PREFER HIGH CLUSTERS PREFER HIGH σσ88

Evrard et al. 2007

CAVEATS/FUTURE WORKCAVEATS/FUTURE WORK HE (10-15% from simulations, e.g. Nagai et al.

2006, Rasia et al. 2006). No results yet on the magnitude for the bias on c (if there is one) due to radial dependence of turbulence

Selection bias Semi-analytic model prediction of c-M Gas physics and AC (problems also with rotation

curves of spirals: Kassim et al. 2006, Gnedin et al. 2006 but also positive claims: M31 mass model of Seigar et al. 2007)

Extend the profiles at large radii (r500 is possible to reach for groups)

MASS CONCLUSIONSMASS CONCLUSIONS

•The crucial mass regime of groups has provided the crucial evidence of the decrease of c with increasing M

•c-M relation offers interesting and novel approach to potentially constrain cosmological parameters

•See constraints on the c-z relation (poster by L. Zappacosta)

ENTROPY PROFILESENTROPY PROFILES

ENTROPY PROFILESENTROPY PROFILES

ENTROPY PROFILESENTROPY PROFILES

THE BASELINE INTRACLUSTER ENTROPY THE BASELINE INTRACLUSTER ENTROPY PROFILE FROM GRAVITATIONAL STRUCTURE PROFILE FROM GRAVITATIONAL STRUCTURE

FORMATIONFORMATION

VOIT ET AL. 2005

COMPARISON WITH MASSIVE CLUSTERS AND COMPARISON WITH MASSIVE CLUSTERS AND GRAVITATIONAL SIMULATIONSGRAVITATIONAL SIMULATIONS

PRATT ET AL. 2006

COMPARISON WITH MASSIVE CLUSTERS AND COMPARISON WITH MASSIVE CLUSTERS AND GRAVITATIONAL SIMULATIONSGRAVITATIONAL SIMULATIONS

COMPARISON WITH MASSIVE CLUSTERS AND COMPARISON WITH MASSIVE CLUSTERS AND GRAVITATIONAL SIMULATIONSGRAVITATIONAL SIMULATIONS

ENTROPY PROFILES FOR AGN ENTROPY PROFILES FOR AGN HEATINGHEATING

VOIT ET AL. 2006

ENTROPY PROFILESENTROPY PROFILES

NGC 4325 AGN DISTURBANCE: RUSSELL ET AL. 2007

ENTROPY PROFILESENTROPY PROFILES

RGH80RGH80

AWM4 AND AGN FEEDBACKAWM4 AND AGN FEEDBACK

“In this scenario there is a clear dichotomy between active and radio quiet clusters: one would expect the cluster population to bifurcate into systems with strong temperature gradients and feedback and those without either”

Donahue et al. 2005

AWM4 AND AGN FEEDBACKAWM4 AND AGN FEEDBACK

AWM4 AND AGN FEEDBACKAWM4 AND AGN FEEDBACK

ENTROPY CONCLUSIONSENTROPY CONCLUSIONS

BROKEN POWER LAW ENTROPY PROFILES FOR GROUPS WITH STEEPER INNER SLOPES AND FLATTER OUTER SLOPES SEEM TO POINT TO HIGHER IMPORTANCE OF LOCAL AGN HEATING

INTERPLAY BETWEEN AGN AND MERGINGS

THE PUZZLE AWM4 (MORE DATA: RADIO, POSTER BY S. GIACINTUCCI, CHANDRA !)