History of IGM

• bench-mark in cosmic structure formation indicating the first luminous structures

Epoch of Reionization (EoR)

z=5.80

z=5.82

z=5.99

z=6.28

The Gunn Peterson Effect

Fan et al 2003

Fast reionization at z=6.3

=> opaque at _obs<0.9m

f(HI) > 0.001 at z = 6.3

Neutral IGM evolution (Gnedin 2000): ‘Cosmic Phase transition’

HI fraction

Density Gas Temp

Ionizing intensity

Normalization: GP absorption, LCDM + z=4 LBGs, T_IGM

8 Mpc (comoving)

• Large scale structure (10’s deg) = Thompson scattering at EoR

• e =Ln_ee = 0.17

=> F(HI) < 0.5 at z=20

WMAP Large scale polarization of CMB (Kogut et al.)

GP + WMAP => Reionization Process is complex, extending from z~20-6? (200-800 Million years after Big Bang)

Fan et al. 2002

Near-edge of reionization: GP Effect

Fairly Fast:• f(HI) > 1e-3 at z >= 6.4 (0.87Gyr)• f(HI) < 1e-4 at z <= 5.7 (1.0 Gyr)

• Problem: _Lya >> 1 for f(HI) > 0.001

Complex reionization example: Double reionization? (Cen 2002)

Pop III stars in ‘mini-halos’ (<1e7 M_sun)‘normal’ galaxies

(>1e8M_sun)

Radio astronomical probes of the Epoch of Reionization and the 1st luminous objects

1. Objects within EoR – Molecular gas, dust, star formation

2. Neutral IGM – HI 21cm emission and absorption

Collaborators

USA – Carilli, Walter, Fan, Strauss, Owen, Gnedin, Djorgovski

Euro – Bertoldi, Menten, Cox, Omont, Beelen

SKA ‘level 0’ science team – Briggs, Carilli, Furlanetto, Gnedin

MAMBO + IRAM 30m

Max-Planck Bolometer array: 133 pixel bolometer camera at 300mK, single mode horns (Kreysa)

Wide fieldimaging and photometry at 250 GHz

rms < 0.5 mJy, res=10.6”, field sizes >= 30’

1. Wide-field imaging at 1.4 GHz: rms=7uJy, 1” res, FoV=30’

Astrometry => avoid confusion

Imaging => AGN vs. Starburst, Lensing?

cm-to-mm SEDs => redshifts, star formation rates unhindered by dust

2. Low order CO transitions at 20 to 50 GHz: rms < 0.1 mJy, res << 1”

Gas excitation and mass estimates

Gas distribution and dynamics, Lensing?

Very Large Array

Plateau de Bure Interferometer

Imaging high order CO lines at 90 to 230 GHz: rms < 0.5 mJy, res < 1” (15% of collecting area of ALMA)

Magic of (sub)mm

350 GHz

250 GHz

L_FIR = 4e12 x S_250(mJy) L_sun for z=0.5 to 8

SFR = 1400 x S_250 M_sun/yr

M_dust = 1.4e8 x S_250 M_sun

SDSS + DPOSS:

700 at z > 4

30 at z > 5

7 at z > 6

M_B < -26 =>

L_bol > 1e14 L_sun

M_BH > 1e9 M_sun

Hunt 2001

High redshift QSOs

QSO host galaxies – M_BH – relation

• Most (all?) low z spheroidal galaxies have SMBH

• M_BH = 0.002 M_bulge

‘Causal connection between SMBH and spheroidal galaxy formation’ (Gebhardt et al. 2002)?

Luminous high z QSOs have massive host galaxies (1e12 M_sun)

• 30% of luminous QSOs have S_250 > 2 mJy, independent of redshift from z=1.5 to 6.4

• L_FIR =1e13 L_sun = 0.1 x L_bol: Dust heating by starburst or AGN?

MAMBO surveys of z>2 DPSS+SDSS QSOs

1148+52 z=6.4

1048+46 z=6.2

1e13L_sun

Arp220

L_FIR vs L’(CO)

M(H_2) = X * L’(CO), X=4 (Milkyway), X=0.8 (ULIRGs)

Telescope time: t(dust) = 1hr, t(CO) = 10hr

Index=1.7

Index=1

1e11 M_sun

•highest redshift quasar known•L_bol = 1e14 L_sun•central black hole: 1-5 x 109 Msun (Willot etal.)•clear Gunn Peterson trough (Fan etal.)

Objects within EoR: QSO 1148+52 at z=6.4

1148+52 z=6.42: MAMBO detection

S_250 = 5.0 +/- 0.6 mJy => L_FIR = 1.2e13 L_sun,

M_dust =7e8 M_sun

3’

VLA Detection of Molecular Gas at z=6.419

46.6149 GHzCO 3-2

Off channels

50 MHz ‘channels’ (320 kms-1, z=0.008)noise: ~57 Jy, D array, 1.5” beam

M(H_2) = 2e10 M_sun

Size < 1.5” (image),

Size > 0.2” (T_B/50K)^-1/2

IRAM Plateau de Bure confirmation

• FWHM = 305 km/s• z = 6.419 +/- 0.001

(3-2)

(7-6)

(6-5)

• Tkin=100K, nH2=105cm-3

VLA imaging of CO3-2 at 0.5” and 0.15” resolution

Separation = 0.3” = 1.7 kpc

T_B = 20K = T_B (starburst)

Merging galaxies?

Or Dissociation by QSO?

rms=50uJy at 47GHz

CO extended to NW by 1” (=5.5 kpc) tidal(?) feature

T_B = 3 K = Milky way

Phase stability: Fast switching at the VLA

10km baseline rms = 10deg

1148+52: starburst+AGN?

SFR(>5 M_sun) = 1400 M_sun/year => host spheroid formation in 5e7 yrs at z > 6?

SMBH formation: n x 2.4e7 yr (Loeb, Wyithe,…)

=> Coeval formation of galaxy/SMBH at z>6?

S_1.4= 55 +/- 12 uJy IRAS 2Jy sample (Yun+)

1148+52

1048+46

•M(dust) = 7e8 M_sun

•M(H_2) = 2e10 M_sun

•M_dyn (r=2kpc) = 4e10 (sin i)-2 M_sun

•M_BH = 3e9 M_sun

M_BH– => M_bulge = 1.5e12 M_sun

• Gas/dust = 30, typical of starburst

• Dynamical vs. gas mass => baryon dominated?

• Dynamical vs. ‘bulge’ mass => M –breaks-down at high z? Or face-on (i < 9deg)?

1148+52: Masses

Cosmic (proper) time

T_univ

• Age of universe: 8.7e8 yr

• C, O production (3e7 M_sun): 1e8 yr

• Fe production (SNe Ia): few e8 yr (Maiolino, Freudling)

• Dust formation: 1.4e9yr (AGB winds) => dust formed in high mass stars/SNR (Dunne et al.. 2003)? => silicate grains?

=> Star formation started early (z > 10)?

Timescales

Cosmic Stromgren Sphere

• Accurate redshift from CO: z=6.419 optical high ionization lines can be off by 1000s km s-1

• Proximity effect: photons leaking from 6.32<z<6.419

z=6.32

•Ionized sphere around QSO: R = 4.7 Mpc ‘time bounded’ Stromgren sphere:

t_qso= 1e5 R^3 f(HI)= 1e7yrs

White et al. 2003

Loeb & Rybicki 2000

Constraints on neutral fraction at z=6.4 GP => f(HI) > 0.001

If f(HI) = 0.001, then t_qso = 1e4 yrs – implausibly short? (see also J1030+0524 z=6.28, J1048+46 z=6.23 using MgII lines)

Probability arguments suggest: f(HI) > 0.1 at z=6.4 – much better limit than GP

Wyithe and Loeb 2003

f_lt = 1e7 yr

Gravitational Lensing?

CO 3-2 double source, 0.3” separation => strong lensing?

Keck near IR imaging: point source < 0.5” at K (Djorgovski)

HST/ACS imaging: point source < 0.3” (Richards 2004)

Radio continuum: Foreground cluster (30x over-density) at z=0.05 => magnification by 2x?

1148+5251

Fan et al. 2002

Near-edge of reionization: GP + Strom. Spheres

Very Fast?• f(HI) > 1e-1 at z >= 6.4 (0.87Gyr)• f(HI) < 1e-4 at z <= 5.7 (1.0 Gyr)

Gas and dust in the first galaxies

• Luminous (star forming?) galaxy: Far IR luminosity = 1e13 Lsun at z=6.42

• Merging(?) galaxy: Molecular gas mass = 2x1010 M_sun, M_dyn = 4e10 (sin i)-2 M_sun

• Early enrichment of heavy elements and dust produced in the first stars => star formation commenced at 0.4 Gyr after the big bang

• Coeval formation of SMBH + stars in earliest galaxies (break-down of M- at high z?)

• Cosmic Stromgren sphere of 4.7 Mpc => ‘witnessing process of reionization’ t_qso = 1e7 * f(HI) yrs ‘fast’ reionization: f(HI)>0.1 at z=6.4?

J1048+4637: A second FIR-luminous QSO source at z=6.2

3.0 +/- 0.4 mJy => L_FIR = 7.5e12 L_sun

M_dust = 4e8 M_sun

Cloverleaf z=2.56, Grav. Lens mag. 11x

VLA detection of HCN emission at 22 GHz => n(H_2) > 1e5 cm^-3 (vs. CO n(H_2) > 1e4 cm^-3) (Solomon, vd Bout, Carilli)

ALMA 1hr

Sensitivity of future arrays: Arp 220 vs z

(FIR = 1e12 L_sun)

EVLA 100hr

Redshifts for obscured/faint sources: wide band (16 - 32 GHz) spectrometers on LMT/GBT (Min Yun 2004)

L_FIR = 1e13 L_sun

Z=10 lensed star forming galaxy? (Pello 2004)

L_app= 4e11 L_sun + LBG dust correction (5x) => L_FIR = 2e12L_sun

S_250 = 0.6 mJy => 5 ALMA detection in 1 minute!

S (CO 4-3 at 42 GHz) = 0.06 mJy => 5 EVLA detection in 15hr

Studying the pristine IGM beyond the EOR: HI 21cm observations with the Square Kilometer Array

and LOFAR

SKA: A/T = 20000 m^2/K => Jy at 200 MHz

Low frequency background – hot, confused sky

Eberg 408 MHz Image (Haslam + 1982)

Coldest regions: T = 200z)^2.6 K

Global HI signature in low frequency spectra

(Gnedin & Shaver 2003)

double

fast21cm ‘fluctuations’ at 1e-4 wrt foreground

HI 21cm Tomography of IGM Zaldarriaga + 2003

z=12 9 7.6

T_B(2’) = 10’s mK

SKA rms(100hr) = 4mK

LOFAR rms (1000hr) = 80mK

Power spectrum analysis

Zaldarriaga + 2003

PAST

LOFAR

SKA

Z=10

129 MHz

2deg 1arcmin

1422+23 z=3.62 Womble 1996

N(HI) = 1e13 -- 1e15 cm^-2, f(HI/HII) = 1e-5 -- 1e-6

=> Before reionization N(HI) =1e18 – 1e21 cm^-2

Cosmic Web after reionization = Ly alpha forest ( <= 10)

Cosmic web before reionization: HI 21cm Forest (Carilli, Gnedin, Owen 2002)

)1()10

1)((008.0 2/1

HI

S

CMB fz

T

T

• SKA ‘observations’ of 21cm absorption before the EOR (A/T = 2000 m^2/K, 240hrs, 1kHz)

• Mean optical depth (z = 10) = 1% = ‘Radio Gunn-Peterson effect’

• Narrow lines (= few %, few km/s) = HI 21cm forest (<= 10), 10/unit z at z=8

• Mini-halos (= 100) (Furlatto & Loeb 2003)

• Primordial disks: low cosmic density (0.001/unit z), but high opacity => fainter radio sources (GRBs?)

Z=10

Z=8

20mJy

Radio sources beyond the EOR?

• Radio loud QSO fraction = 10% to z=5.8 (Petric + 2003)

• Models => expect 0.05 to 0.5 deg^-2 at z> 6 with S_151 > 6 mJy (out of 100 total)

2240 at z > 6

1.4e5 at z > 6

S_151 > 6mJy

Carilli + 2002

Haiman & Hui 2004

Terrestrial interference

100 MHz 200 MHz

GMRT 230 MHz 0924-220 z=5.2

GMRT 230 MHz 0924-220 z=5.2 Continuum point source = 0.55 Jy

Noise limited spectra: =5.5 mJy/channel

HI 21cm absorption at z=5.200? = 4%, v = 130 km/s N(HI) = 9e20 (Ts/100K) cm^-2

SKA timeline

•2004 Science case: “Science with the SKA” Carilli & Rawlings, New Astron. Rev.

•2004-7 demonstrator development major external review (2006) submit funding proposals for a 5% demonstrator

•2006 site selection: Autralia, USA-SW, South Africa, China

•2008 selection of technical design (may be a combination); start construction of 5% demonstrator on chosen site

•2009 submit funding proposals for full array

•2012 start construction

•2020 complete construction

Projected cost: 1 G$

Radio astronomy – Probing the EoR

•Study physics of the first luminous sources (limited to near-IR to radio wavelengths)

•Currently limited to pathological systems (‘HLIRGs’)

•EVLA and ALMA 10-100x sensitivity is critical for study of ‘normal’ galaxies

•SKA is the only means to study the neutral IGM

z

Ultimate goal: Far side of the moon?

No RFI

No ionosphere

Cheap, ‘dirty’ antennas

No moving parts

130MHz