The Mass in Galaxy Clusters

from X-ray/SZ observables

Stefano EttoriINAF-OA / INFN Bologna

X-ray Planck SDSS

z=8.55 z=5.7 z=1.4 z=0

P(k)+ΛCDM

Structure formation in the Universe

We know how the gravity forms structures on cluster scales. X-rays (SZ) provide a direct probe of the thermalized gas

in a cluster’s potential.

cluster

R2500(~0.3 R200~CXO limit)

R500(~0.7 R200~few best CXO & XMM cases)

Bkg: dominant in GCs outskirts

Simulation for 3keV cluster @ R200 (Ettori & Molendi arXiv:1005.0382)

Gal foreground

Ins. background

Residual CXB

Source

z=8.55 z=5.7 z=1.4 z=0

P(k)+ΛCDM

Structure formation in the Universe

We know how the gravity forms structures on cluster scales. X-rays (SZ) provide a direct probe of the thermalized gas

in a cluster’s potential.

cluster

Coma Planck+13

Total mass from SZ/X-rays

€

Mtot < r( ) = −kTgas(r) rGµmp

∂ ln ngas∂ ln r

+∂ ln Tgas∂ ln r

$

% &

'

( )

€

Mtot ∝ ΔRΔ3 ⇒∝ T 3 / 2 ∝ Mg ∝ L

3 / 4 ∝YX3 / 5

•  low counts statistic: scaling relations (for galaxy clusters mass function: Mtot vs L/T/Mgas/YX or a combination of these…)Ettori et al., 2012; Ettori, 2013 & 2014

•  high counts statistic: mass profiles (calibration & hydrostatic bias; ~200 out of 1743 obj known, Piffaretti et al. 11)Ettori et al., 2010, A&A, 524, 68; Baldi, Ettori et al., 2012, A&A, 537, 142; Eckert et al., 2013, A&A, 551, 23; Planelles et al., 2013, MNRAS; Roncarelli et al., 2013, MNRAS; Ettori et al., 2013, SSRv, arXiv:1303.3530

X-ray mass: CLASH (Donahue+14)

MCXO/MWL@0.5Mpc: 0.88±0.07 MCXO/MSWL@0.5Mpc: 1.11±0.07

MXMM/MSWL@0.5Mpc: 0.82±0.10MXMM/MWL@0.5Mpc: 0.76±0.05

X-WL mass: CoMaLit (Sereno+Ettori14) Comparing Masses in Literature (CoMaLit)

I. Bias and scatter in WL and X-ray mass estimates of clusters II. The scaling relation between M and Planck YSZ

III. Literature Catalogs of weak lensing galaxy clustersIV. Evolution and self-similarity of scaling relations:

the cases of M – {σopt, R, LX, YSZ}

Thermodynamic properties of the ICM for 18 objects in common with Planck SZ thermal pressure and the ROSAT X-ray gas density profiles

(Eckert et al. 13a & 13b)

The X-ray/SZ view out to R200

CC / nCC

T = P/n K = P/n5/3 M = -r2/(G μ m n) dP/dr

The X-ray/SZ view out to R200

500R/R0.5 1 1.5 2

gas

f

0.05

0.1

0.15

0.2

6obj CC12obj NCCAverage CCAverage NCC

WMAP7

200RPlanck+ROSAT (Eckert et al. 2013b)

The X-ray/SZ view out to R200

500R/R0.5 1 1.5 2

gas

f

0.05

0.1

0.15

0.2

6obj CC12obj NCCAverage CCAverage NCC

WMAP7

200R

HE violation?Clumping?

Planck+ROSAT (Eckert et al. 2013b)

Clusters of galaxies: outskirtsXMM-LP (PI: Eckert):

12 objects @z=0.04-0.1, to cover up to R200,

& S/N>10 in Planck data

A2255

A2319

A644

Clusters of galaxies: outskirtsA2142 (~1.3e15 M¤, z=0.09)

Combined X-SZ analysis (Tchernin+15)

XMM Planck

R200 deproj(Smean) / deproj(Smedian)

The Athena Observato ry

L2 orbit Ariane V Mass < 5100 kg Power 2500 W 5 year mission

X-ray Integral Field Unit: ΔE: 2.5 eV Field of View: 5 arcmin Operating temp: 50 mk

Wide Field Imager: ΔE: 125 eV Field of View: 40 arcmin High countrate capability

Silicon Pore Optics: 2 m2 at 1 keV 5 arcsec HEW Focal length: 12 m Sensitivity: 3 10-17 erg cm-2 s-1

Rau et al. 2013 arXiv1307.1709 Barret et al., 2013 arXiv:1308.6784

Willingale  et al, 2013 arXiv1308.6785

The fo rmat ion and evo lu t ion o f c lus te r s and g roups o f ga lax ies

How and when was the energy contained in the hot intra-cluster medium generated?

How does ordinary matter assemble into the large-scale structures that we see today?

Ettori, Pratt et al., 2013 arXiv1306.2322

With 100k-sec WFI exposure, gas emissivity, T, Z with 2, 3, 18% (90% c.l.) can be measured at R200.

The fo rmat ion and evo lu t ion o f c lus te r s and g roups o f ga lax ies

How and when was the energy contained in the hot intra-cluster medium generated?

How does ordinary matter assemble into the large-scale structures that we see today?

Ettori, Pratt et al., 2013 arXiv1306.2322

The fo rmat ion and evo lu t ion o f c lus te r s and g roups o f ga lax ies

How and when was the energy contained in the hot intra-cluster medium generated?

How does ordinary matter assemble into the large-scale structures that we see today?

Ettori, Pratt et al., 2013 arXiv1306.2322

The fo rmat ion and evo lu t ion o f c lus te r s and g roups o f ga lax ies

How and when was the energy contained in the hot intra-cluster medium generated?

Bulk motion and turbulent broadening of FeXXV Ka line. With 100k-sec X-IFU exposure, 0+20, 200±5, 400±10 km/s can be resolved.

Simulated Velocity map

100 km/s 500

Ettori, Pratt, et al., 2013 arXiv1306.2322

Total mass from SZ/X-rays

Mtot ∝ Lα M βg T

γ ; 4α +3β + 2γ = 3

•  low counts statistic: scaling relations (for galaxy clusters mass function: Mtot vs L/T/Mgas/YX or a combination of these…)Ettori et al. 2012; Ettori 2013 & 2014

Total mass is the fundamental tool to use Galaxy clusters as cosmological probes

Total mass from SZ/X-rays

Mtot ∝ Lα M βg T

γ ; 4α +3β + 2γ = 3

•  low counts statistic: scaling relations (for galaxy clusters mass function: Mtot vs L/T/Mgas/YX or a combination of these…)Ettori et al. 2012; Ettori 2013 & 2014

Total mass is the fundamental tool to use Galaxy clusters as cosmological probes

Mtot ~ Mgas α T -1.5α+1.5

α = 0 … Mtot ~ T 1.5α = 1 … Mtot ~ Mgasα = 3/5 … Mtot ~ (Mgas T) 3/5 ~ Y 3/5

Mtot ~ L α T -2α+1.5

α = 0 … Mtot ~ T 1.5α = 3/4 … Mtot ~ L 3/4α = 1/2 … Mtot ~ (LT) 1/2

X-ray/SZ scaling relations: Self-similar +{fg, C, β}

The self-similar scenario predictsslope and z-evolution of the power-law

relations between Mtot & X-ray/SZ quantities

and also the normalization

The self-similar predictions on normalization & slope can fully

explain the observed X-SZ SL once {fg(M), βP(M), C} are considered

X-ray/SZ scaling relations: Self-similar +{fg, C, β}

Here, the normalizations & slopes are analytic

X-ray/SZ scaling relations: Self-similar +{fg, C, β}

X-ray/SZ scaling relations: Self-similar +{fg, C, β}

(Ettori14)

Conclusions (waiting for Athena)

•  from simulations, we are understanding biases & scatter in hydrostatic & lensing masses; the measured distribution explains the observed MHE/Mlens (but still large deviations btw different samples)

•  Combining X-ray+SZ profiles is a promising tool to recover (clumping-free) cluster physical quantities (and also MHE)

•  generalized-SRs & physical-SRs define a framework for X-ray/SZ scaling laws that permit to reconstruct M with the lowest scatter (up to 50% lower than the one from standard-SRs)