Physics of the Intracluster Medium from Present and Future X-Ray Instruments

Physics of the intracluster medium from present and future X-ray instruments

Maxim Markevitch (NASA Goddard)

August 7, 2015 Cluster precision cosmology

− 0.6 B AO −0.7 all −0.8 SN Ia

−0.9 Cosmological −1.0

0 constant W

w MA −1.1 P −1.2 clusters +WMAP −1.3 clusters −1.4

−1.5 0.60 0.65 0.70 0.75 0.80 0.85 ΩDE Vikhlinin 09 Cluster precision cosmology only as precise as our knowledge of cluster physics

− 0.6 B AO −0.7 all −0.8 SN Ia

−0.9 Cosmological −1.0 ±10% mass error

0 constant W

w MA −1.1 P −1.2 clusters +WMAP −1.3 clusters −1.4

−1.5 0.60 0.65 0.70 0.75 0.80 0.85 ΩDE Vikhlinin 09 “Nuisance parameters”

AGN and star formation feedback — Chandra bubbles, shocks around them

Radiative cooling — match simulations with observed density proﬁles; high-res XMM RGS and Astro-H spectra

ICM clumpiness (related to cooling) Chandra ultra-deep observations

Turbulence, bulk motions — Astro-H details in this talk

Thermal conduction — T maps, proﬁles details in this talk

Viscosity — cold front stability

Electron-ion non-equipartition — shock fronts

Magnetic ﬁelds, cosmic ray electrons (mostly radio) match radio with X-ray

Cosmic ray protons — Fermi upper limit

Helium abundance — SZ / X-ray Cold fronts in A2142

100 kpc

• KH instabilities — await MHD simulations to constrain effective viscosity “Nuisance parameters”

AGN and star formation feedback — Chandra bubbles, shocks around them

Radiative cooling — match simulations with observed density proﬁles; high-res XMM RGS and Astro-H spectra

ICM clumpiness (related to cooling) Chandra ultra-deep observations

Turbulence, bulk motions — Astro-H details in this talk

Thermal conduction — T maps, proﬁles details in this talk

Viscosity — cold front stability

Electron-ion non-equipartition — shock fronts

Magnetic ﬁelds, cosmic ray electrons (mostly radio) match radio with X-ray

Cosmic ray protons — Fermi upper limit

Helium abundance — SZ / X-ray Electron-proton equilibration timescale from shock fronts

Bullet cluster shock

τep ≪ Coulomb 3D

τep = Coulomb

1600 km/s

MM 06

• 95% conﬁdence: τep ≪ Coulomb “Nuisance parameters”

AGN and star formation feedback — Chandra bubbles, shocks around them

Radiative cooling — match simulations with observed density proﬁles; high-res XMM RGS and Astro-H spectra

ICM clumpiness (related to cooling) Chandra ultra-deep observations

Turbulence, bulk motions — Astro-H details in this talk

Thermal conduction — T maps, proﬁles details in this talk

Viscosity — cold front stability

Electron-ion non-equipartition — shock fronts

Magnetic ﬁelds, cosmic ray electrons (mostly radio) match radio with X-ray

Cosmic ray protons — Fermi upper limit

Helium abundance — SZ / X-ray

“Nuisance parameters”

AGN and star formation feedback — Chandra bubbles, shocks around them

Radiative cooling — match simulations with observed density proﬁles; high-res XMM RGS and Astro-H spectra

ICM clumpiness (related to cooling) Chandra ultra-deep observations

Turbulence, bulk motions — Astro-H details in this talk

Thermal conduction — T maps, proﬁles details in this talk

Viscosity — cold front stability

Electron-ion non-equipartition — shock fronts

Magnetic ﬁelds, cosmic ray electrons (mostly radio) match radio with X-ray

Cosmic ray protons — Fermi upper limit

Helium abundance — SZ / X-ray New constraints on large-scale heat conduction

(B. Russel 2014 PhD thesis; Russell, MM, ZuHone in prep.) Observational constraints on ICM conductivity so far

• Conduction across cold fronts must be strongly suppressed (Ettori & Fabian 2000, ...)

• Stripped tails of infalling groups survive → strong suppression (Eckert et al. 14)

— both can be explained by magnetic draping

• Small-scale temperature structure in mergers, e.g., A754 → suppressed by ×10 – 40 (Markevitch et al. 03)

— can be a selection effect (pick thermally isolated regions)

Cluster-wide, large-scale thermal conduction? Cluster temperature proﬁles — radial decline

1.5

1.0 i T h / T 0.5

ASCA (Markevitch et al. 98) Chandra (Vikhlinin et al. 05)

0.0 0.2 0.4 0.6 0.8 r/r180

• XMM, Suzaku results similar (Molendi & Leccardi 08; George et al. 09; ...) A2029, a prototypical hot relaxed cluster

1017

r 500•a r 500 •b 1016 ρtot 3 − 10 1015 Mpc ρgas ⊙ V e 2D M 14 , 10 ,k ρ T

5 3D ⊙ 1013 M , M 1012

0 1011 10 100 1000 10 100 1000 r, kpc r, kpc

Vikhlinin et al. 06 If the cluster were a solid body ...

no cooling, 0.3 Spitzer isotropic conduction

r 2500 r 500 0 Gyr 1 2

B. Russell 14

• conduction erases T gradient If the cluster is hydrostatic ...

no cooling, 0.3 Spitzer isotropic conduction, allow gas redistribution

r 2500 r 500 0 Gyr 1 8

B. Russell 14

• T gradient maintained because of cluster compression

(result very similar to McCourt 13) Evolution of gas density proﬁle

no cooling, 0.3 Spitzer isotropic conduction

r 2500 r 500

1 0 Gyr

B. Russell 14 Evolution of gas density proﬁle

cooling, 0.3 Spitzer isotropic conduction

r 2500 r 500

1 0 Gyr

B. Russell 14

• for r > 0.5 r 2500, result doesn’t depend on details of heating and feedback in cool core Observed differential f gas proﬁles in hot relaxed clusters

T > 5 keV, z < 0.25 relaxed clusters • very low scatter! ) ∆ r ( gas f fractional intrinsicfractional scatter 0.05 0.1 0.2 0.5 500 2500 0.00 0.05 0.10 0.15 0.20 105 104 103 102 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

∆ r r2500 Mantz et al. 14 • The sample of relaxed clusters should contain clusters of different “ages” (time since last major disturbance)

• If κ , 0, clusters of different age should have different f gas = scatter in the sample Evolution of differential f gas proﬁle with conduction

30% Spitzer

2 • 1 •

• 1 • • Mantz 14

0 Gyr • •

B. Russell 14 Evolution of differential f gas proﬁle with conduction

20% Spitzer

3 •

2 • 1 • • • 1 • Mantz 14

0 Gyr • •

B. Russell 14 Evolution of differential f gas proﬁle with conduction

10% Spitzer

3 • 5 •

4 • 2 • • • 3 • 2 • Mantz 14 1 • 1 • 0 Gyr • •

B. Russell 14 Evolution of differential f gas proﬁle with conduction

5% Spitzer

5 • 8 • 4 • 7 • 6 • 3 • • • 5 2 • 4 • Mantz 14 3 • 1 • 2 • • 0 Gyr 1 • •

B. Russell 14 Conclusions on conduction

• Under simple assumptions, κ > 5 – 10% Spitzer (in the cluster radial direction)

contradicts the observed lack of scatter in f gas at r ∼ r 2500 in hot, relaxed clusters

• Cosmological simulations including heat conduction and the relaxed cluster selection as in Mantz 14 may place stronger constraints ICM turbulence (direct measurements)

Astro-H instruments

/20 /+!+/2/+/D:B9+('+

/20 .+!+/2. -20+!+-2.+/BD>+<:@@>A /,)+/4>=+<>56

% *7764B:C6+&@63+/4< $ $# $## $### #"$ $ $# $## $### *=6@8E+/;61 Astro-H instruments (relevant for clusters)

Soft X-ray Spectrometer Soft X-ray Imager Hard X-ray Imager

(SXS) (SXI) (HXI)

Detectortechnology microcalorimeter CCD Si/CdTecross-strips

Effectivearea 210cm2 at6keV 300cm2 at30keV 360cm2 at 6 keV

Energyrange 0.4–12keV 0.3–12keV 5–80keV

Energy resolution, FWHM 5 eV < 200eV 2keV

Angularresolution,HPD 1.2′ 1.2′ 1.7′

FOV 3′ × 3′ (6×6pixelarray) 38′ × 38′ 9′ × 9′ Can resolve turbulently broadened Fe line:

5 eV resolution at E = 6.5 keV → σ LOS = 100 km/s

100 ks simulation of Perseus core (expected exposure much longer) Likely early cluster projects (Astro-H White Paper, arxiv:1412.1176)

• Perseus core: turbulence, bulk motions, rare elements, 3.5 keV line

• Centaurus: line-rich cool core, cooling gas EM distribution

• M87: velocity of SW arm

• A2029, the most relaxed cluster: constrain turbulence at r 2500

to σ LOS < 150 km/s ( ∼ 2% of thermal pressure)

• Power spectrum of turbulence in Coma Power spectrum of turbulence r (arcmin) 1 2 3 5 10 15 100 100 kpc -1 100 10 200 kpc

10-2 300 kpc 500 kpc 10-3 cascade 1000 kpc )

3 -1 10-4 10 2 z (Mpc w

-5 2 z

10 / w / -6 injection 10 SF(r) (k) 3D P 10-7 10-2 dissipation

10-8

10-9

10-10 10-3 10-4 10-3 10-2 10-1 101 102 103 k (kpc−1 ) r (kpc)

• Dissipation scale, power-law slope → plasma microphysics (can’t measure)

• Injection scale + normalization (can measure) → (a) energy ﬂow down the cascade, (b) diffusion and mixing rate (for metals, entropy, cosmic rays, ...) Coma is the best cluster to study turbulence

A simple system:

• No cooling ﬂow, a big ﬂat core → turbulence should develop in an isotropic, textbook fashion on all scales • No central AGN → turbulence is driven only by cluster mergers

A well-studied radio halo — can estimate efﬁciency of turbulent acceleration of cosmic rays Expected constraints on power spectrum

• ﬁt line width and “structure function” (average velocity difference as a function of angular separation)

5× 100 ks pointings Coma

0.7 100 kpc 200 kpc 0.6 big cross 300 kpc 500 kpc 1000 kpc 0.5

M Z = 0.3 )

3 0.4 (Mpc 2 z w

/ 0.3 n C

0.2 spectrum normalization

0.1

200 kpc 0.0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8

lmax (Mpc)

ZuHone et al. 15 injection scale but ... with 5 eV resolution for the ﬁrst time, expect surprises