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Radio observations of the formation of the first galaxies and supermassive Black Holes Chris Carilli (NRAO) LANL Cosmology School, July 2010 • Concepts and tools in radio astronomy: dust, cool gas, and star formation • Quasar host galaxies at z=6: coeval formation of massive galaxies and SMBH within 1 Gyr of the Big Bang • Quasar near-zones and reionization •Bright future: pushing to normal galaxies with the Atacama Large Millimeter Array and Expanded Very Large Array – recent examples! ESO Collaborators: R.Wang, D. Riechers, Walter, Fan, Bertoldi, Menten, Cox, Strauss, Neri Millimeter through centimeter astronomy: unveiling the cold, obscured universe optical mid-IR CO Submm = dust Galactic GN20 SMG z=4.0 • optical studies provide a limited view of star and galaxy formation • cm/mm reveal the dust-obscured, earliest, most active phases of star and galaxy formation HST/CO/SUBMM Cosmic ‘Background’ Radiation 30 nW m-2 sr-1 17 nW m-2 sr-1 Over half the light in the Universe is absorbed by dust and reemitted in the FIR Franceschini 2000 Radio – FIR: obscuration-free estimate of massive star formation Radio: SFR = 1x10-21 L1.4 W/Hz FIR: SFR = 3x10-10 LFIR (Lo) Magic of (sub)mm: distance independent method of studying objects in universe from z=0.8 to 10 LFIR ~ 4e12 x S250(mJy) Lo SFR ~ 1e3 x S250 Mo/yr FIR = 1.6e12 L_sun 1000 Mo/yr obs = 250 GHz 7 Spectral lines cm submm z=0.2 Atomic fine structure lines Molecular rotational lines z=4 Molecular gas CO = total gas masses = fuel for star formation M(H2) = α L’(CO(1-0)) Velocities => dynamical masses Gas excitation => ISM physics (densities, temperatures) Dense gas tracers (eg. HCN) => gas directly associated with star formation Astrochemistry/biology Wilson et al. CO image of ‘Antennae’ merging galaxies Fine Structure lines [CII] 158um (2P3/2 - 2P1/2) Principal ISM gas coolant: efficiency of photo-electric heating by dust grains. Traces star formation and the CNM Fixsen et al. [CII] CO [OI] 63um [CII] COBE: [CII] most luminous cm to FIR line in the Galaxy ~ 1% Lgal Herschel: revolutionary look at FSL in nearby Universe – AGN/star formation diagnostics [OIII] 88um [CII] Cormier et al. [OIII]/[CII] MAMBO at 30m Powerful suite of existing cm/mm facilites First glimpses into early galaxy formation 30’ field at 250 GHz rms < 0.3 mJy Very Large Array Plateau de Bure Interferometer 30’ field at 1.4 GHz High res imaging at 90 to 230 GHz rms< 10uJy, 1” res rms < 0.1mJy, res < 0.5” High res imaging at 20 to 50 GHz rms < 0.1 mJy, res < 0.2” Massive galaxy and SMBH formation at z~6: gas, dust, star formation in quasar hosts SDSS Apache Point NM Why quasars? Rapidly increasing samples: z>4: > 1000 known z>5: > 100 z>6: 20 Spectroscopic redshifts Extreme (massive) systems MB < -26 => Lbol > 1014 Lo MBH > 109 Mo (Eddington / MgII) 1148+5251 z=6.42 6.4 Gunn-Peterson Effect SDSS z~6 quasars => tailend of reionization and first (new) light? z=6.4 5.7 QSO host galaxies MBH – Mbulge relation Nearby galaxies Haaring & Rix All low z spheroidal galaxies have SMBH: MBH=0.002 Mbulge ‘Causal connection between SMBH and spheroidal galaxy formation’ Luminous high z quasars have massive host galaxies (1012 Mo) Cosmic Downsizing Massive galaxies form most of their stars rapidly at high z ~(e-folding time)-1 Currently active star formation tH-1 Red and dead => Require active star formation at early times Zheng+ • Massive old galaxies at high z • Stellar population synthesis in nearby ellipticals Dust in high z quasar host galaxies: 250 GHz surveys HyLIRG Wang sample 33 z>5.7 quasars • 30% of z>2 quasars have S250 > 2mJy • LFIR ~ 0.3 to 1.3 x1013 Lo (~ 1000xMilky Way) • Mdust ~ 1.5 to 5.5 x108 Mo Dust formation at tuniv<1Gyr? • AGB Winds ≥ 1.4e9yr High mass star formation? (Dwek, Anderson, Cherchneff, Shull, Nozawa) ‘Smoking quasars’: dust formed in BLR winds (Elvis) SMC, z<4 quasars Galactic z~6 quasar, GRBs ISM dust formation (Draine) • Extinction toward z=6.2 QSO and z~6 GRBs => different mean grain properties at z>4 (Perley, Stratta) Larger, silicate + amorphous carbon dust grains formed in core collapse SNe vs. eg. graphite Stratta et al. Dust heating? Radio to near-IR SED FIR excess = 47K dust SED consistent with star forming galaxy: SFR ~ 400 to 2000 Mo yr-1 low z SED TD = 47 K TD ~ 1000K Star formation? AGN Radio-FIR correlation Fuel for star formation? Molecular gas: 8 CO detections at z ~ 6 with PdBI, VLA 1mJy • M(H2) ~ 0.7 to 3 x1010 (α/0.8) Mo • Δv = 200 to 800 km/s CO excitation: Dense, warm gas, thermally excited to 6-5 230GHz 691GHz starburst nucleus Milky Way • LVG model => Tk > 50K, nH2 = 2x104 cm-3 • Galactic Molecular Clouds (50pc): nH2~ 102 to 103 cm-3 • GMC star forming cores (≤1pc): nH2~ 104 cm-3 LFIR vs L’(CO): ‘integrated Kennicutt-Schmidt star formation law’ • Further circumstantial evidence for star formation SFR • Gas consumption time (Mgas/SFR) decreases with SFR FIR ~ 1010 Lo/yr => tc~108yr FIR ~ 1013 Lo/yr => tc~107yr 1e3 Mo/yr Index=1.5 MW 1e11 Mo Mgas => Need gas re-supply to build giant elliptical 1148+52 z=6.42: VLA imaging at 0.15” resolution CO3-2 VLA IRAM 1” ~ 6kpc + 0.3” ‘molecular galaxy’ size ~ 6 kpc – only direct observations of host galaxy of z~6 quasar! Double peaked ~ 2kpc separation, each ~ 1kpc TB ~ 35 K ~ starburst nuclei Gas dynamics => ‘weighing’ the first galaxies z=6.42 -150 km/s 7kpc +150 km/s CO only method for deriving dynamical masses at these distances Dynamical mass (r < 3kpc) ~ 6 x1010 Mo M(H2)/Mdyn ~ 0.3 Gas dynamics: CO velocities -150 km/s z=4.4 z=4.19 +150 km/s Dynamical masses ~ 0.4 to 2 x1011 Mo M(H2)/Mdyn ≥ 0.5 => gas/baryons dominate inner few kpc Break-down of MBH – Mbulge relation at very high z z>4 QSO CO z<0.2 QSO CO Low z galaxies Riechers + <MBH/Mbulge> ~ 15 higher at z>4 => Black holes form first? Wang z=6 sample: galaxy mass vs. inclination, assuming all have CO radii ~ J1148+5251 Wang + Low z MBH/Mbulge • Departure from MBH – Mbulge at highest z, or •All face-on: i < 20o [CII] 158um search in z > 6.2 quasars For z>6 => redshifts to 250GHz => Bure! [CII] 1” [NII] •L[CII] = 4x109 Lo (L[NII] < 0.1L[CII] ) •S250GHz = 5.5mJy •S[CII] = 12mJy • S[CII] = 3mJy • S250GHz < 1mJy => don’t pre-select on dust 1148+5251 z=6.42:‘Maximal star forming disk’ PdBI 250GHz 0.25”res • [CII] size ~ 1.5 kpc => SFR/area ~ 1000 Mo yr-1 kpc-2 • Maximal starburst (Thompson, Quataert, Murray 2005) Self-gravitating gas and dust disk Vertical disk support by radiation pressure on dust grains ‘Eddington limited’ SFR/area ~ 1000 Mo yr-1 kpc-2 eg. Arp 220 on 100pc scale, Orion SF cloud cores < 1pc [CII] • [CII]/FIR decreases with LFIR = lower gas heating efficiency due to charged dust grains in high radiation environments • Opacity in FIR may also play role (Papadopoulos) Malhotra [CII] z >4 • HyLIRG at z> 4: large scatter, but no worse than low z ULIRG • Normal star forming galaxies are not much harder to detect in [CII] (eg. LBG, LAE) Maiolino, Bertoldi, Knudsen, Iono, Wagg A starburst to quasar sequence at the highest z? Anticorrelation of EW(Lya) with submm detections No Dust Submm dust • Strong FIR => starburst • Weak Lya => young quasar, prior to build-up of BLR (?) • Consistent with ‘Sanders sequence’: starburst to composite to quasar Submm dust No Dust Summary cm/mm observations of 33 quasars at z~6: only direct probe of the host galaxies 160uJy EVLA J1425+3254 CO at z = 5.9 11 in mm continuum => Mdust ~ 108 Mo: Dust formation in SNe? 10 at 1.4 GHz continuum: Radio to FIR SED => SFR ~ 1000 Mo/yr 8 in CO => Mgas ~ 1010 Mo = Fuel for star formation in galaxies High excitation ~ starburst nuclei, but on kpc-scales Follow star formation law (LFIR vs L’CO): tc ~ 107 yr 3 in [CII] => maximal star forming disk: 1000 Mo yr-1 kpc-2 Departure from MBH – Mbulge at z~6: BH form first? Anticorrel. EW(Lya) with submm detections => SB to Q sequence 10 Extreme Downsizing: Building a giant elliptical galaxy + SMBH at tuniv< 1Gyr Plausible? Multi-scale simulation isolating most massive halo in 3 Gpc3 Stellar mass ~ 1e12 Mo forms in series (7) of major, gas rich mergers from z~14, with SFR 1e3 Mo/yr 6.5 SMBH of ~ 2e9 Mo forms via Eddington-limited accretion + mergers Evolves into giant elliptical galaxy in massive cluster (3e15 Mo) by z=0 Li, Hernquist et al. Li, Hernquist+ • Rapid enrichment of metals, dust in ISM • Rare, extreme mass objects: ~ 100 SDSS z~6 QSOs on entire sky • Goal: push to normal galaxies at z > 6 BREAK Discussion points: 1.Dust formation within 1Gyr of Big Bang? 2.Evolution of MBH – Mbulge relation? 3.Starburst to quasar sequence: duty cycles and timescales? 4.Gas resupply (CMA, mergers)? 5.FIR – EW(Lya) anti-correlation? ESO Quasar Near Zones: J1148+5251 • Accurate host galaxy redshift from CO: z=6.419 • Quasar spectrum => photons leaking down to z=6.32 White et al. 2003 • ‘time bounded’ Stromgren sphere ionized by quasar • Difference in zhost and zGP => RNZ = 4.7Mpc [fHI Nγ tQ]1/3 (1+z)-1 HI HII Loeb & Barkana Quasar Near-Zones: sample of 25 quasars at z=5.7 to 6.5 (Carilli et al. 2010) I.Host galaxy redshifts: CO (6), MgII (11), UV (8) I.GP on-set redshift: •Adopt fixed resolution of 20A •Find 1st point when transmission drops below 10% (of extrapolated) = well above typical GP level. z = 6.1 Wyithe et al. 2010 Quasar Near-Zones: Correlation of RNZ with UV luminosity Nγ1/3 LUV Quasar Near-Zones: RNZ vs redshift RNZ = 7.3 – 6.5(z-6) z>6.15 •<RNZ> decreases by factor 2.3 from z=5.7 to 6.5 => fHI increases by factor 9 • Pushing into tail-end of reionization? Alternative hypothesis to Stromgren sphere: Quasar Proximity Zones (Bolton & Wyithe) • RNZ measures where density of ionizing photon from quasar > background photons (IGRF) => RNZ [Nγ]1/2 (1+z)-9/4 • Increase in RNZ from z=6.5 to 5.7 is then due to rapid increase in mfp and density of ionizing background during overlap or ‘percolation’ stage of reionization • Either case (CSS or PZ) => rapid evolution of IGM from z ~ 6 to 6.5 What is Atacama Large Milllimeter Array? North American, European, Japanese, and Chilean collaboration to build & operate a large millimeter/submm array at high altitude site (5000m) in northern Chile => order of magnitude, or more, improvement in all areas of (sub)mm astronomy, including resolution, sensitivity, and frequency coverage. ALMA Specs • High sensitivity array = 54x12m • Wide field imaging array = 12x7m antennas • Frequencies = 80 GHz to 720 GHz • Resolution = 20mas res at 700 GHz • Sensitivity = 13uJy in 1hr at 230GHz What is EVLA? First steps to the SKA-high By building on the existing infrastructure, multiply ten-fold the VLA’s observational capabilities, including: 10x continuum sensitivity (1uJy) Full frequency coverage (1 to 50 GHz) 80x Bandwidth (8GHz) + 104 channels 40mas resolution at 40GHz Overall: ALMA+EVLA provide > order magnitude improvement from 1GHz to 1 THz! Pushing to normal galaxies: spectral lines 100 Mo yr-1 at z=5 cm telescopes: star formation, low order molecular transitions -- total gas mass, dense gas tracers (sub)mm: dust, high order molecular lines, fine structure lines -- ISM physics, dynamics ALMA and first galaxies: [CII] and Dust 100Mo/yr 10Mo/yr Wide bandwidth spectroscopy J1148+52 at z=6.4 in 24hrs with ALMA • ALMA: Detect multiple lines, molecules per 8GHz band • EVLA 30 to 38 GHz = CO2-1 at z=5.0 to 6.7 => large cosmic volume searches for molecular gas (1 beam = 104 cMpc3) w/o need for optical redshifts ALMA Status •Antennas, receivers, correlator in production: best submm receivers and antennas ever! •Site construction well under way: Observation Support Facility, Array Operations Site, 5 Antenna interferometry at high site! • Early science call Q1 2011 embargoed first light image EVLA Status • Antenna retrofits 70% complete (100% at ν ≥ 18GHz). • Full receiver complement completed 2012 with 8GHz bandwidth • Early science started March 2010 using new correlator (up to 2GHz bandwidth) – already revolutionizing our view of galaxy formation! GN20 molecule-rich proto-cluster at z=4 CO 2-1 in 3 submm galaxies, all in 256 MHz band 0.3mJy z=4.055 4.051 4.056 0.7mJy CO2-1 46GHz 0.4mJy • SFR ~ 103 Mo/year • Mgas > 1010 Mo • Early, clustered massive galaxy formation 1000 km/s GN20 z=4.0 VLA: ‘pseudo-continuum’ 2x50MHz channels EVLA: well sampled velocity field GN20 moment images +250 km/s -250 km/s • Low order CO emitting regions are large (10 to 20 kpc) • Gas mass = 1.3e11 Mo • Stellar mass = 2.3e11 Mo • Dynamical mass (R < 4kpc) = 3e11 Mo => Baryon dominated within 4kpc Most distant SMG: z=5.3 (Riechers et al) EVLA Bure CO excitation => ISM conditions • nH2 ~ 104.3 cm-3 • TK ~ 45 K CO 1-0 in normal galaxies at z=1.5 (‘sBzK’ galaxies) Bure 2-1 HST EVLA 1-0 4” 0.3mJy 500 km/s • SFR ~ 10 to 100 Mo/year • Find: MH2 > 1010 Mo> Mstars => early stage of MWtype galaxy formation? • Again: low order CO is big (28kpc) • Milky Way-like CO excitation (low order key!) •10x more numerous than SMGs Dense gas history of the Universe: the ‘other half’ of galaxy formation Tracing the fuel for galaxy formation over cosmic time Millennium Simulations Obreschkow & Rawlingn SF law Major observational goal for next decade EVLA/ALMA Deep fields: 1000hr, 50 arcmin2 • Volume (EVLA, z=2 to 2.8) = 1.4e5 cMpc3 • 1000 galaxies z=0.2 to 6.7 in CO with M(H2) > 1010 Mo • 100 in [CII] z ~ 6.5 • 5000 in dust continuum END Discussion points 1.Stromgren spheres vs. Proximity zones? 2.DGHU, star formation laws, and CO to H2 conversion factors? 3.Role of EVLA/ALMA in first galaxy studies? Pushing to normal galaxies: continuum A Panchromatic view of 1st galaxy formation 100 Mo yr-1 at z=5 cm: Star formation, AGN (sub)mm Dust, FSL, mol. gas Near-IR: Stars, ionized gas, AGN Comparison to low z quasar hosts z=6 quasars IRAS selected Stacked mm non-detections PG quasars Hao et al. 2005 Molecular gas mass: X factor M(H2) = X L’(CO(1-0)) Milky way: X = 4.6 MO/(K km/s pc^2) (virialized GMCs) ULIRGs: X = 0.8 MO/(K km/s pc^2) (CO rotation curves) Optically thin limit: X ~ 0.2 Downes + Solomon Milky Way-type gas conditions Mgas HyLIRG 1.5 Dannerbauer + 1 Daddi + SFR CO excitation = Milky Way (but mass > 10xMW) FIR/L’CO Milky Way Gas depletion timescales > few x108 yrs Building a giant elliptical galaxy + SMBH at tuniv< 1Gyr 10 • Rapid enrichment of metals, dust in ISM • Rare, extreme mass objects: ~ 100 SDSS z~6 QSOs on entire sky Issues and questions: • Duty cycle for star formation and SMBH accretion very 6.5 high? • Gas resupply: not enough to build GE • Goal: push to normal galaxies at z > 6Li, Issues Hernquist et al. Quasar Near-Zones Nγ1/3 LUV • Correlation of RNZ with UV luminosity • No correlation of UV luminosity with redshift