C.Carilli (NRAO) Heidelberg 05 History of IGM F(HI) = 0 C.Carilli (NRAO) Heidelberg 05 F(HI) = 1 Epoch of Reionization (EoR) last phase of cosmic evolution to be tested bench-mark in cosmic structure formation indicating the first luminous structures F(HI) = 1e-5

=> opaque at l_obs<0.9mm The Gunn Peterson Effect z=5.80 z=5.82 z=5.99 z=6.28 End of reionization f(HI) > 0.001 at z = 6.3 => opaque at l_obs<0.9mm Fan et al 2003

Near-edge of reionization: GP Effect Fairly Fast: f(HI) > 1e-3 at z >= 6.3 (0.87Gyr) f(HI) < 1e-4 at z <= 5.7 (1.0 Gyr) Although cf. Songaila, Oh, Stern, Malhotra… Fan + 2005; White + 2005

Normalization: GP absorption, LCDM + z=4 LBGs, T_IGM Neutral IGM evolution (Gnedin 2004): ‘Cosmic Phase transition’ at z=6 to 7 8 Mpc (comoving) Normalization: GP absorption, LCDM + z=4 LBGs, T_IGM

WMAP Large scale polarization of CMB (Kogut et al.) CMB Temperature fluctuations imprinted by primordial density fluctuations at last scattering (z=1000) Large scale polarization: Thompson scattering at EoR t_e = 0.17 => F(HI) < 0.5 at z=17 20deg

GP + CMB => ‘complex’ reionization extending from z=20 to 6? Limitations of current measurements: CMB polarization: -- t_e = Ln_es_e = integral measure through universe => allows many reionization scenarios Gunn-Peterson effect: -- t_Lya >>1 for f(HI)>0.001 -- High z universe is opaque at (observed) optical wavelengths  Reionization occurs in ‘twilight zone’, observable at near-IR through radio wavelengths

CMB: large scale polarization + secondary anisotropies Radio astronomical probes of the Epoch of Reionization and the 1st luminous objects CMB: large scale polarization + secondary anisotropies Objects within EoR – Molecular gas, dust, star formation, process of reionization Neutral IGM – HI 21cm emission and absorption Collaborators USA – Carilli, Walter, Fan, Strauss, Owen, Gnedin, Lo Euro – Bertoldi, Cox, Menten, Omont, Beelen SKA Key Program science team– Briggs, Carilli, Furlanetto, Rawlings Science with the Square Kilometer Array (NAR, Carilli & Rawlings) http://www.skatelescope.org/pages/page_astronom.htm

IRAM 30m + MAMBO: sub-mJy sens at 250 GHz + wide fields  dust IRAM PdBI: sub-mJy sens at 90 and 230 GHz + arcsec resol. mol. gas VLA: uJy sens at 1.4 GHz  star formation VLA: < 0.1 mJy sens at 20-50 GHz + 0.2” resol.  mol. gas (low order)

L_FIR = 4e12 x S_250(mJy) L_sun SFR = 1e3 x S_250 M_sun/yr FIR = 1.6e12 L_sun Magic of (sub)mm: distance independent method of studying objects in universe for z=0.8 to 8 L_FIR = 4e12 x S_250(mJy) L_sun SFR = 1e3 x S_250 M_sun/yr Radio-FIR (Yun+ 02)

High Redshift QSOs: SDSS, DPSS (Fan 2005) z>4: 950 known z>5: 52 z>6: 8 30 at z~6 expected in the whole survey M_B < -26 => L_bol > 1e14 L_sun M_BH > 1e9 M_sun

QSO host galaxies – M_BH – s relation Most (all?) low z spheroidal galaxies have SMBH: M_BH=0.002M_bulge ‘Causal connection between SMBH and spheroidal galaxy formation’ (Gebhardt et al. 2002)? Luminous high z QSOs have massive host galaxies (1e12 M_sun)

MAMBO surveys of z>2 DPSS+SDSS QSOs 1e13L_sun 1048+46 z=6.2 Arp220 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?

Telescope time: t(dust) = 1hr, t(CO) = 10hr L_FIR vs L’(CO) High-z sources 1e3 M_sun/yr Index=1 1e11 M_sun Index=1.7 M(H_2) = X * L’(CO), X=4 (Milkyway), X=0.8 (ULIRGs) Telescope time: t(dust) = 1hr, t(CO) = 10hr

VLA detections of HCN 1-0 emission n(H_2) > 1e5 cm^-3 (vs. CO: n(H_2) > 1e3 cm^-3) index=1 Solomon et al z=2.58 70 uJy

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

Cosmic (proper) time 1/16 T_univ = 0.87Gyr

1148+52 z=6.42: Dust and Gas detection M(H_2) = 2e10 M_sun L_FIR = 1.2e13 L_sun, M_dust =7e8M_sun Off channels Rms=60uJy 46.6149 GHz CO 3-2 S_250 = 5.0 +/- 0.6 mJy Dust formation: 1.4e9yr (AGB winds) > t_univ (8.7e8yr) => dust formed in high mass stars? => silicate grains? C, O production (3e7 M_sun): few e8 yr => Star formation started early (z = 10)?

 Typical of starburst nuclei (eg. NGC253, Arp220) IRAM Plateau de Bure n2 (6-5) (7-6) (3-2) Tkin=100K, nH2=105cm-3 FWHM = 305 km/s z = 6.419 +/- 0.001  Typical of starburst nuclei (eg. NGC253, Arp220)

VLA imaging of CO3-2 at 0.4” and 0.15” resolution rms=50uJy at 47GHz Separation = 0.3” = 1.7 kpc T_B = 20K  Typical of starburst nuclei Merging galaxies? CO extended to NW by 1” (=5.5 kpc) tidal(?) feature

Stellar spheroid formation in few e7 yrs = e-folding time for SMBH 1148+5251: radio-FIR SED Beelen et al. S_1.4= 55 +/- 12 uJy 1048+46 T_D = 50 K Star forming galaxy characteristics: radio-FIR SED, Gas/Dust, CO excitation and T_B => Coeval starburst/AGN? SFR = 1e3 M_sun/yr Stellar spheroid formation in few e7 yrs = e-folding time for SMBH => Coeval formation of galaxy/SMBH at z = 6.4 ?

M_BH = 3e9 M_sun => M_bulge = 1.5e12 M_sun 1148+52: Masses M(dust) = 7e8 M_sun M(H_2) = 2e10 M_sun M_dyn (r=2.5kpc) = 5e10 M_sun M_BH = 3e9 M_sun => M_bulge = 1.5e12 M_sun Gas/dust = 30, typical of starburst Dynamical vs. gas mass => baryon dominated? Dynamical vs. ‘bulge’ mass => M – s breaks-down at high z? [SMBH forms first?]

Cosmic Stromgren Sphere Accurate redshift from CO: z=6.419+/0.001 Ly a, high ioniz Lines: inaccurate redshifts (Dz > 0.03) Proximity effect: photons leaking from 6.32<z<6.419 White et al. 2003 z=6.32 ‘time bounded’ Stromgren sphere: R = 4.7 Mpc t_qso= 1e5 R^3 f(HI)= 1e7yrs

Loeb & Rybicki 2000

<Dz> = 0.08 => <R> = 4.4 Mpc z>6 QSOs with MgII and/or CO redshifts (Wyithe et al. 05) <Dz> = 0.08 => <R> = 4.4 Mpc

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 given QSO fiducial lifetimes (1e7 years)? Probability arguments suggest: f(HI) > 0.1 P(>x_HI) 10% Wyithe et al. 2005 90% probability x(HI) > curve t_qso/1e7 yrs

Near-edge of reionization: GP + Cosmic Stromgren Spheres Very Fast? f(HI) > 1e-1 at z > 6.4 (0.87Gyr) f(HI) < 1e-4 at z < 5.7 (1.0 Gyr) See also Cosmic Stromgren Surfaces (Mesinger & Haiman 2004 but cf. Oh & Furnaletto 2005)

Molecular Gas and dust during the EoR FIR luminous galaxy at z=6.42: 1e13 Lsun observe dust, gas, star formation, AGN Sub-kpc imaging: Merging galaxy: M_gas= 2x1010 M_sun, M_dyn=6e10 M_sun Early enrichment of heavy elements and dust produced => star formation 0.4 Gyr after the big bang High z: Coeval formation of SMBH + stars and break-down of M-s at high z? Cosmic Stromgren sphere = 4.7 Mpc => ‘witnessing process of reionization’ t_qso = 1e7 * f(HI) yrs ‘fast’ reionization: f(HI)>0.1 at z=6.4?

(sub)mm: Dust, molecular gas Near-IR: Stars, ionized gas, AGN Continuum sensitivity of future arrays: Arp 220 vs z (FIR = 1.6e12 L_sun) cm: Star formation, AGN (sub)mm: Dust, molecular gas Near-IR: Stars, ionized gas, AGN

Studying the pristine IGM beyond the EOR: redshifted HI 21cm observations (100 – 200 MHz) with the Square Kilometer Array. ‘Pathfinders’: LOFAR, MWA, PAST, VLA-VHF,… SKA goal: mJy at 200 MHz Large scale structure: density, f(HI), T_spin

Low frequency background – hot, confused sky Eberg 408 MHz Image (Haslam + 1982) Coldest regions: T = 100 (n/200 MHz)^-2.6 K Highly ‘confused’: 3 sources/arcmin^2 with S_0.2 > 0.1 mJy

Interference Ionospheric phase errors TIDs – ‘fuzz-out’ sources 100 MHz z=13 200 MHz z=6 Ionospheric phase errors TIDs – ‘fuzz-out’ sources ‘Isoplanatic patch’ = few deg = few km Phase variation proportional to wavelength^2 74MHz Lane 03

Global reionization signature in low frequency HI spectra (Gnedin & Shaver 2003) fast 21cm ‘deviations’ at 1e-4 wrt foreground double Spectral index deviations of 0.001

HI 21cm Tomography of IGM Zaldarriaga + 2003 9 7.6 DT_B(2’) = 10’s mK SKA rms(100hr) = 4mK LOFAR rms (1000hr) = 80mK

Power spectrum analysis Zaldarriaga + 2003 Z=10 129 MHz LOFAR SKA 2deg 1arcmin

Cosmic web before reionization: HI 21Forest Cosmic Web after reionization = Ly alpha forest (d <= 10) 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 before reionization: HI 21Forest radio G-P (t=1%) 21 Forest (10%) mini-halos (10%) primordial disks (100%) expect 0.05 to 0.5 deg^-2 at z> 6 with S_151 > 6 mJy (Carlli,Jarvis,Haiman) z=12 z=8 20mJy 130MHz

‘Pathfinders’: PAST, LOFAR, MWA, VLA-VHF, … MWA prototype (MIT/ANU) LOFAR (NL) PAST (CMU/China) VLA-VHF (CfA/NRAO)

Leverage: existing telescopes, IF, correlator, operations VLA-VHF: 180 – 200 MHz Prime focus X-dipole Greenhill, Blundell (SAO Rx lab); Carilli, Perley (NRAO) Leverage: existing telescopes, IF, correlator, operations $110K D+D/construction (CfA) First light: Feb 16, 05 Four element interferometry: May 05 First limits: Dec 05

Main Experiment: Cosmic Stromgren spheres around z=6 to 6 Main Experiment: Cosmic Stromgren spheres around z=6 to 6.5 SDSS QSOs (Wyithe & Loeb 2004) VLA-VHF 190MHz 250hrs 20 f(HI) mK 15’ VLA spectral/spatial resolution well matched to expected signal: 7’, 1000 km/s Set first hard limits on f(HI) at end of cosmic reionization (f(HI) < 0.3) Easily rule-out cold IGM (T_s < T_cmb): signal = 360 mK 0.50+/-0.12 mJy

Other Experiments: power spectrum analysis, ‘HI 21cm forest’ 2deg

System characteristics First sidelobe = 14% (goal < 5%) Efficiency = 28% (goal: 50%) Xpol = 20% (goal: 5%) T_sys = 50 (Rx) + 150 (sky) K FoV = 12 deg^2 rms/chan= 0.12mJy in 250 hrs (goal) Correlator: 0.8MHz/chan, 16 chan, 2 pol. 4deg 3C313 --first image

Main hurdle: Interference! Digital TV: 186 to 192MHz, 200 W from ABQ KNMD Ch 9 Digital TV

Radio astronomy – Probing the EoR ‘Twilight zone’:physics of 1st luminous sources (limited to near-IR to radio wavelengths) Currently limited to pathological systems (‘HLIRGs’) EVLA, ALMA 10-100x sensitivity is critical to study normal galaxies Low freq pathfinders: HI 21cm signatures of neutral IGM SKA imaging of IGM z=6.4

=> Solar Metalicity PKS 2322+1944 z=4.12: [CI] (492 GHz rest freq; Pety et al.) VLA CO2-1 PdBI => Solar Metalicity

GMRT 228 MHz – HI 21cm abs toward highest z radio galaxy, 0924-220 z=5 RFI = 20 kiloJy ! 8GHz 1” Van Breugel et al. rms/(40km/s chan) = 5 mJy 230Mhz point source = 0.55 Jy; z(CO)

Richards et al. 2002 SDSS QSOs 1000km/s => Dz = 0.03

J1048+4637: A second FIR-luminous QSO source at z=6.2 S_250 = 3.0 +/- 0.4 mJy=> L_FIR=7.5e12 L_sun VLA CO(3-2) z(opt) z(MgII) GBT/EVLA/ALMA/LMT correlator: 8–32 GHz, 16000 channels

Gunn-Peterson effect Barkana and Loeb 2001

Complex reionization example: Double reionization. (Cen 2002; cf Complex reionization example: Double reionization? (Cen 2002; cf. Furlanetto, Gnedin,…) Pop III stars in ‘mini-halos’ (<1e7 M_sun) ‘normal’ galaxies (>1e8M_sun) Recombination time < hubble time at z > 8 Stellar fusion produces 7e6eV/H atom, reionization requires 13.6eV/H atom =>Need to process only 1e-5 of baryons through stars to reionize the universe