The Distributions of Baryons in the Universe

and the Warm Hot Intergalactic Medium

Baryonic budget at z=0

Overall thermal timeline of baryons from z=1000 0

Three separate redshift intervals in history

Conclusions

Renyue Cen (Princeton University Observatory)Sept 26, 2013

@Anisotropic Universe: from microwaves to ultrahigh energiesUniversity van Amsterdam

The Bottom 5% in the Standard Model: The Bottom 5% in the Standard Model:

Komatsu et al (2011) WMAP7Planck Collaboration (2013)

Warm-Hot Intergalactic Medium (WHIM) z~0

T=105-7Kelvin &Density=(1-300)

mean density

Cen & Ostriker (1999)

WHIMn=0.96, 8 = 0.8,

xh2 = 0.126, H0 = 70

WHIM

Power Spectrum in the Standard Model

Cosmological Recom-bination

RealDarkAges

Pop III Stars1stgen Galaxies1stgen Quasarsreheating

Lya forestMajority of QuasarsEllipticals

Majority ofGalaxiesClusters

LSS

Redshiftz=1100 30 – 10 6 - 2 2 - 010-6

2nd genGalaxiesQuasarsFinal Reion

Temp103 K

104 K

106 K

102 K

106Msun 1014Msun1012Msun109MsunMass(nonlinear)

Budget, Structure, Thermal Timeline: Budget, Structure, Thermal Timeline: Heating of the Cosmic Baryons by Fusion Heating of the Cosmic Baryons by Fusion

and Gravitational Energy and Gravitational Energy

Baryonbudget

evolution

1. SDSS QSOs: zzriri~6.0~6.0

SDSS 1030+0524z=6.28

Which translates to zzriri=8.2-13.0 (2σ)=8.2-13.0 (2σ)

(assuming a step function like transition from a

totally neutral to totally ionized universe)

2. CMB optical depth=0.088 +- 0.015=0.088 +- 0.015

Fan et al (2002)

Epoch of Reionization Observational Data: z~20 to 6

Komatsu et al (2011) WMAP7

z~20 to 6ab initio theory:

the universecan be

reionizedby stars

(mostly Pop II stars),

producing optical depth

that is consistent

with WMAP7, but the process

is NOT a step function

like and spatially very inhomogene

ous Trac, Cen, … (2013)

A list of major observational probes of EoR

CMB: probing ionized hydrogen (bubbles)

21cm in radio: probing neutral hydrogen

Ground based infrared surveys: probing Ly emission of galaxies

HST & JWST: probing rest-frame optical-UV continuum

High-z QSOs: absorption

High-z GRBs: absorption as well as SFR

IR radiation background

9

Cen et al (1994)

z=3

zem3.6 QSOWomble et al (1996)

• The standard model + gravitational instability + photoionization +

hydrodynamics A successful model for Ly

observed forest A powerful method to

determine Pk on small scales (~1Mpc), complementary to CMB and others

Photoionization heated, T~104K Lyforest:

z~6 to 2

Gravitational re-heating of the universe: z~2 to 0

Cen & Ostriker (1999)

The process is complexbut the essential physics

is rather simple:H(z) L(z) vshock

z~20 ab initio theory: the universe is heated by waves breaking

due to gravitational collapse of large-scale structure at moderate to low redshift

Cen (1999)

Capitalistic development of baryonic universe: z=2 to 0

Cen & Ostriker (1999)

A list of major observational probes of z=2 to 0 IGM

QSO absorption lines (H, He, metals)

Emission lines (Ly, C IV, OVI, …)

X-ray emission from groups/clusters (lines and continuum)

SZ effects

Soft X-ray background (intensity, correlation function)

Cosmic rays produced in shocks radio emission

The intergalactic medium in the observable universe have three characteristic redshift ranges

z=100 20: universe expansion cooling

z=20 2: universe being heated by photoionization from star formation (nuclear energy) from 10 to 104K

z=2 0: universe being heated by hydrodynamic shock waves produced by gravitational collapse of large-scale structure from 104 to 106K --- IGM “measure” the temperature of the universe

Conclusions