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ESO 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! Collaborators: R.Wang, D. Riechers, Walter, Fan, Bertoldi, Menten, Cox, Strauss, Neri
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Millimeter through centimeter astronomy: unveiling the cold, obscured universe GN20 SMG z=4.0 Galactic Submm = dust optical CO 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 mid-IR
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Cosmic ‘Background’ Radiation Franceschini 2000 Over half the light in the Universe is absorbed by dust and reemitted in the FIR 30 nW m -2 sr -1 17 nW m -2 sr -1
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Radio – FIR: obscuration-free estimate of massive star formation Radio: SFR = 1x10 -21 L 1.4 W/Hz FIR: SFR = 3x10 -10 L FIR (L o )
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Magic of (sub)mm: distance independent method of studying objects in universe from z=0.8 to 10 L FIR ~ 4e12 x S 250 (mJy) L o SFR ~ 1e3 x S 250 M o /yr FIR = 1.6e12 L _sun obs = 250 GHz 1000 M o /yr 7
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Spectral lines Molecular rotational lines Atomic fine structure lines z=0.2 z=4 cm submm
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Molecular gas CO = total gas masses = fuel for star formation M(H 2 ) = 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
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Fine Structure lines [CII] 158um ( 2 P 3/2 - 2 P 1/2 ) Principal ISM gas coolant: efficiency of photo-electric heating by dust grains. Traces star formation and the CNM COBE: [CII] most luminous cm to FIR line in the Galaxy ~ 1% L gal Herschel: revolutionary look at FSL in nearby Universe – AGN/star formation diagnostics [CII] CO [OI] 63um [CII] [OIII] 88um [CII] [OIII]/[CII] Cormier et al. Fixsen et al.
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Plateau de Bure Interferometer High res imaging at 90 to 230 GHz rms < 0.1mJy, res < 0.5” MAMBO at 30m 30’ field at 250 GHz rms < 0.3 mJy Very Large Array 30’ field at 1.4 GHz rms< 10uJy, 1” res High res imaging at 20 to 50 GHz rms < 0.1 mJy, res < 0.2” Powerful suite of existing cm/mm facilites First glimpses into early galaxy formation
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Massive galaxy and SMBH formation at z~6: gas, dust, star formation in quasar hosts Why quasars? Rapidly increasing samples: z>4: > 1000 known z>5: > 100 z>6: 20 Spectroscopic redshifts Extreme (massive) systems M B L bol > 10 14 L o M BH > 10 9 M o (Eddington / MgII) 1148+5251 z=6.42 SDSS Apache Point NM
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Gunn-Peterson Effect Fan et al 2006 SDSS z~6 quasars => tail- end of reionization and first (new) light? z=6.4 5.7 6.4
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QSO host galaxies M BH – M bulge relation All low z spheroidal galaxies have SMBH: M BH =0.002 M bulge ‘Causal connection between SMBH and spheroidal galaxy formation’ Luminous high z quasars have massive host galaxies (10 12 M o ) Haaring & Rix Nearby galaxies
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Cosmic Downsizing Massive galaxies form most of their stars rapidly at high z t H -1 Currently active star formation Red and dead => Require active star formation at early times Zheng+ ~(e-folding time ) -1 Massive old galaxies at high z Stellar population synthesis in nearby ellipticals
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30% of z>2 quasars have S 250 > 2mJy L FIR ~ 0.3 to 1.3 x10 13 L o (~ 1000xMilky Way) M dust ~ 1.5 to 5.5 x10 8 M o HyLIRG Dust in high z quasar host galaxies: 250 GHz surveys Wang sample 33 z>5.7 quasars
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Dust formation at t univ <1Gyr? AGB Winds ≥ 1.4e9yr High mass star formation? (Dwek, Anderson, Cherchneff, Shull, Nozawa) ‘Smoking quasars’: dust formed in BLR winds (Elvis ) 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. z~6 quasar, GRBs Galactic SMC, z<4 quasars
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Dust heating? Radio to near-IR SED T D = 47 K FIR excess = 47K dust SED consistent with star forming galaxy: SFR ~ 400 to 2000 M o yr -1 Radio-FIR correlation low z SED T D ~ 1000K Star formation? AGN
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Fuel for star formation? Molecular gas: 8 CO detections at z ~ 6 with PdBI, VLA M(H 2 ) ~ 0.7 to 3 x10 10 (α/0.8) M o Δv = 200 to 800 km/s 1mJy
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CO excitation: Dense, warm gas, thermally excited to 6-5 LVG model => T k > 50K, n H2 = 2x10 4 cm -3 Galactic Molecular Clouds (50pc): n H2 ~ 10 2 to 10 3 cm -3 GMC star forming cores (≤1pc): n H2 ~ 10 4 cm -3 Milky Way starburst nucleus 230GHz691GHz
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L FIR vs L’(CO): ‘integrated Kennicutt-Schmidt star formation law’ Index=1.5 1e11 M o 1e3 M o /yr Further circumstantial evidence for star formation Gas consumption time (M gas /SFR) decreases with SFR FIR ~ 10 10 L o /yr => t c ~10 8 yr FIR ~ 10 13 L o /yr => t c ~10 7 yr => Need gas re-supply to build giant elliptical SFR M gas MW
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1148+52 z=6.42: VLA imaging at 0.15” resolution IRAM 1” ~ 6kpc CO3-2 VLA ‘molecular galaxy’ size ~ 6 kpc – only direct observations of host galaxy of z~6 quasar! Double peaked ~ 2kpc separation, each ~ 1kpc T B ~ 35 K ~ starburst nuclei + 0.3”
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CO only method for deriving dynamical masses at these distances Dynamical mass (r < 3kpc) ~ 6 x10 10 M o M(H 2 )/M dyn ~ 0.3 Gas dynamics => ‘weighing’ the first galaxies z=6.42 -150 km/s +150 km/s 7kpc
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Dynamical masses ~ 0.4 to 2 x10 11 M o M(H 2 )/M dyn ≥ 0.5 => gas/baryons dominate inner few kpc Gas dynamics: CO velocities z=4.19z=4.4 -150 km/s +150 km/s
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Break-down of M BH – M bulge relation at very high z z>4 QSO CO z<0.2 QSO CO Low z galaxies Riechers + ~ 15 higher at z>4 => Black holes form first?
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Wang z=6 sample: galaxy mass vs. inclination, assuming all have CO radii ~ J1148+5251 Departure from M BH – M bulge at highest z, or All face-on: i < 20 o Wang + Low z M BH /M bulge
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For z>6 => redshifts to 250GHz => Bure! 1” [CII] [NII] [CII] 158um search in z > 6.2 quasars L [CII] = 4x10 9 L o (L [NII] < 0.1L [CII] ) S 250GHz = 5.5mJy S [CII] = 12mJy S [CII] = 3mJy S 250GHz < 1mJy => don’t pre-select on dust
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1148+5251 z=6.42:‘Maximal star forming disk’ [CII] size ~ 1.5 kpc => SFR/area ~ 1000 M o 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 M o yr -1 kpc -2 eg. Arp 220 on 100pc scale, Orion SF cloud cores < 1pc PdBI 250GHz 0.25”res
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[CII] [CII]/FIR decreases with L FIR = lower gas heating efficiency due to charged dust grains in high radiation environments Opacity in FIR may also play role (Papadopoulos) Malhotra
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[CII] 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 z >4
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A starburst to quasar sequence at the highest z? Anticorrelation of EW(Lya) with submm detections 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 Submm dust No Dust
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11 in mm continuum => M dust ~ 10 8 M o : Dust formation in SNe? 10 at 1.4 GHz continuum: Radio to FIR SED => SFR ~ 1000 M o /yr 8 in CO => M gas ~ 10 10 M o = Fuel for star formation in galaxies High excitation ~ starburst nuclei, but on kpc-scales Follow star formation law (L FIR vs L’ CO ): t c ~ 10 7 yr 3 in [CII] => maximal star forming disk: 1000 M o yr -1 kpc -2 Departure from M BH – M bulge at z~6: BH form first? Anticorrel. EW(Lya) with submm detections => SB to Q sequence J1425+3254 CO at z = 5.9 Summary cm/mm observations of 33 quasars at z~6: only direct probe of the host galaxies EVLA 160uJy
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Extreme Downsizing: Building a giant elliptical galaxy + SMBH at t univ < 1Gyr Plausible? Multi-scale simulation isolating most massive halo in 3 Gpc 3 Stellar mass ~ 1e12 M o forms in series (7) of major, gas rich mergers from z~14, with SFR 1e3 M o /yr SMBH of ~ 2e9 M o forms via Eddington-limited accretion + mergers Evolves into giant elliptical galaxy in massive cluster (3e15 M o ) by z=0 6.5 10 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 Li, Hernquist et al. Li, Hernquist+
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ESO BREAK Discussion points: 1.Dust formation within 1Gyr of Big Bang? 2.Evolution of M BH – M bulge relation? 3.Starburst to quasar sequence: duty cycles and timescales? 4.Gas resupply (CMA, mergers)? 5.FIR – EW(Lya) anti-correlation?
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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 z host and z GP => R NZ = 4.7Mpc [f HI N γ t Q ] 1/3 (1+z) -1
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HI Loeb & Barkana HII
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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 1 st point when transmission drops below 10% (of extrapolated) = well above typical GP level. Wyithe et al. 2010 z = 6.1
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Quasar Near-Zones: Correlation of R NZ with UV luminosity N γ 1/3 L UV
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decreases by factor 2.3 from z=5.7 to 6.5 => f HI increases by factor 9 Pushing into tail-end of reionization? R NZ = 7.3 – 6.5(z-6) Quasar Near-Zones: R NZ vs redshift z>6.15
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Alternative hypothesis to Stromgren sphere: Quasar Proximity Zones (Bolton & Wyithe) R NZ measures where density of ionizing photon from quasar > background photons (IGRF) => R NZ [N γ ] 1/2 (1+z) -9/4 Increase in R NZ 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
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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.
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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
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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) + 10 4 channels 40mas resolution at 40GHz Overall: ALMA+EVLA provide > order magnitude improvement from 1GHz to 1 THz!
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(sub)mm: dust, high order molecular lines, fine structure lines -- ISM physics, dynamics cm telescopes: star formation, low order molecular transitions -- total gas mass, dense gas tracers Pushing to normal galaxies: spectral lines 100 M o yr -1 at z=5
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ALMA and first galaxies: [CII] and Dust 100M o /yr 10M o /yr
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Wide bandwidth spectroscopy 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 = 10 4 cMpc 3 ) w/o need for optical redshifts J1148+52 at z=6.4 in 24hrs with ALMA
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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
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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!
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GN20 molecule-rich proto-cluster at z=4 CO 2-1 in 3 submm galaxies, all in 256 MHz band 4.051 z=4.055 4.056 0.7mJy CO2-1 46GHz 0.4mJy 1000 km/s 0.3mJy SFR ~ 10 3 M o /year M gas > 10 10 M o Early, clustered massive galaxy formation
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GN20 z=4.0 VLA: ‘pseudo-continuum’ 2x50MHz channels EVLA: well sampled velocity field
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GN20 moment images +250 km/s -250 km/s Low order CO emitting regions are large (10 to 20 kpc) Gas mass = 1.3e11 M o Stellar mass = 2.3e11 M o Dynamical mass (R < 4kpc) = 3e11 M o => Baryon dominated within 4kpc
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CO excitation => ISM conditions n H2 ~ 10 4.3 cm -3 T K ~ 45 K Most distant SMG: z=5.3 (Riechers et al) EVLA Bure
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CO 1-0 in normal galaxies at z=1.5 (‘sBzK’ galaxies) 4” SFR ~ 10 to 100 M o /year Find: M H2 > 10 10 M o > M stars => early stage of MW- type galaxy formation? Again: low order CO is big (28kpc) Milky Way-like CO excitation (low order key!) 10x more numerous than SMGs 500 km/s Bure 2-1 HST EVLA 1-0 0.3mJy
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Dense gas history of the Universe: the ‘other half’ of galaxy formation Tracing the fuel for galaxy formation over cosmic time SF law Millennium Simulations Obreschkow & Rawlingn Major observational goal for next decade
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EVLA/ALMA Deep fields: 1000hr, 50 arcmin 2 Volume (EVLA, z=2 to 2.8) = 1.4e5 cMpc 3 1000 galaxies z=0.2 to 6.7 in CO with M(H 2 ) > 10 10 M o 100 in [CII] z ~ 6.5 5000 in dust continuum
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END Discussion points 1.Stromgren spheres vs. Proximity zones? 2.DGHU, star formation laws, and CO to H 2 conversion factors? 3.Role of EVLA/ALMA in first galaxy studies?
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cm: Star formation, AGN (sub)mm Dust, FSL, mol. gas Near-IR: Stars, ionized gas, AGN Pushing to normal galaxies: continuum A Panchromatic view of 1 st galaxy formation 100 M o yr -1 at z=5
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Comparison to low z quasar hosts IRAS selected PG quasars z=6 quasars Stacked mm non-detections Hao et al. 2005
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Molecular gas mass: X factor M(H 2 ) = X L’(CO(1-0)) Milky way: X = 4.6 M O /(K km/s pc^2) (virialized GMCs) ULIRGs: X = 0.8 M O /(K km/s pc^2) (CO rotation curves) Optically thin limit: X ~ 0.2 Downes + Solomon
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CO excitation = Milky Way (but mass > 10xMW) FIR/L’CO Milky Way Gas depletion timescales > few x10 8 yrs HyLIRG Dannerbauer + Daddi + Milky Way-type gas conditions 1 1.5 M gas SFR
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Building a giant elliptical galaxy + SMBH at t univ < 1Gyr 6.5 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 high? Gas resupply: not enough to build GE Goal: push to normal galaxies at z > 6 Issues Li, Hernquist et al.
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Quasar Near-Zones N γ 1/3 Correlation of R NZ with UV luminosity No correlation of UV luminosity with redshift L UV
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