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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

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  1. 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 ESO

  2. Millimeter through centimeter astronomy: unveiling the cold, obscured universe Submm = dust optical mid-IR CO 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

  3. 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

  4. Radio – FIR: obscuration-free estimate of massive star formation • Radio: SFR = 1x10-21 L1.4 W/Hz • FIR: SFR = 3x10-10 LFIR (Lo)

  5. 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

  6. Spectral lines submm cm z=0.2 Atomic fine structure lines z=4 Molecular rotational lines

  7. 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

  8. 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 • 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 Fixsen et al. [CII] CO [OI] 63um [CII] [OIII]/[CII] [OIII] 88um [CII] Cormier et al.

  9. 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 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” Plateau de Bure Interferometer High res imaging at 90 to 230 GHz rms < 0.1mJy, res < 0.5”

  10. SDSS Apache Point NM 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 MB < -26 => Lbol> 1014 Lo MBH > 109 Mo (Eddington / MgII) 1148+5251 z=6.42

  11. Gunn-Peterson Effect 6.4 SDSS z~6 quasars => tail-end of reionization and first (new) light? z=6.4 5.7 Fan et al 2006

  12. 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)

  13. 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

  14. 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 x108Mo

  15. 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) • 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 SMC, z<4 quasars Galactic z~6 quasar, GRBs Stratta et al.

  16. Dust heating? Radio to near-IR SED low z SED TD ~ 1000K TD = 47 K • FIR excess = 47K dust • SED consistent with star forming galaxy: • SFR ~ 400 to 2000 Mo yr-1 Star formation? AGN Radio-FIR correlation

  17. Fuel for star formation? Molecular gas: 8 CO detections at z ~ 6 with PdBI, VLA • M(H2)~ 0.7 to 3 x1010 (α/0.8) Mo • Δv = 200 to 800 km/s 1mJy

  18. 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

  19. LFIR vs L’(CO): ‘integrated Kennicutt-Schmidt star formation law’ • Further circumstantial evidence for star formation • Gas consumption time (Mgas/SFR) decreases with SFR FIR ~ 1010 Lo/yr => tc~108yr FIR ~ 1013 Lo/yr => tc~107yr • => Need gas re-supply to build giant elliptical SFR 1e3 Mo/yr Index=1.5 MW 1e11 Mo Mgas

  20. 1148+52 z=6.42: VLA imaging at 0.15” resolution CO3-2 VLA IRAM 0.3” 1” ~ 6kpc + • ‘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

  21. 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

  22. Gas dynamics: CO velocities z=4.4 z=4.19 -150 km/s +150 km/s • Dynamical masses ~ 0.4 to 2 x1011 Mo • M(H2)/Mdyn ≥ 0.5 => gas/baryons dominate inner few kpc

  23. 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?

  24. 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

  25. [CII] 158um search in z > 6.2 quasars [CII] 1” [NII] For z>6 => redshifts to 250GHz => Bure! • S[CII] = 3mJy • S250GHz < 1mJy • => don’t pre-select on dust • L[CII] = 4x109 Lo (L[NII] < 0.1L[CII] ) • S250GHz = 5.5mJy • S[CII] = 12mJy

  26. 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

  27. [CII] Malhotra • [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)

  28. [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

  29. 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

  30. Summary cm/mm observations of 33 quasars at z~6: only direct probe of the host galaxies EVLA 160uJy 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

  31. Extreme Downsizing: Building a giant elliptical galaxy + SMBH at tuniv< 1Gyr 10 • Plausible? Multi-scale simulation isolating most massive halo in 3Gpc3 • Stellar mass ~ 1e12 Mo forms in series (7) of major, gas rich mergers from z~14, with SFR 1e3 Mo/yr • SMBH of ~ 2e9 Mo forms via Eddington-limited accretion + mergers • Evolves into giant elliptical galaxy in massive cluster (3e15 Mo) by z=0 6.5 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

  32. BREAK Discussion points: Dust formation within 1Gyr of Big Bang? Evolution of MBH – Mbulge relation? Starburst to quasar sequence: duty cycles and timescales? Gas resupply (CMA, mergers)? FIR – EW(Lya) anti-correlation? ESO

  33. 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

  34. HI HII Loeb & Barkana

  35. Quasar Near-Zones: sample of 25 quasars at z=5.7 to 6.5 • (Carilli et al. 2010) • Host galaxy redshifts: CO (6), MgII (11), UV (8) • 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

  36. Quasar Near-Zones: Correlation of RNZ with UV luminosity Nγ1/3 LUV

  37. 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?

  38. 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

  39. 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.

  40. 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

  41. 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!

  42. 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

  43. ALMA and first galaxies: [CII] and Dust 100Mo/yr 10Mo/yr

  44. 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

  45. 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

  46. 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!

  47. 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 0.4mJy 0.7mJy CO2-1 46GHz • SFR ~ 103 Mo/year • Mgas > 1010 Mo • Early, clustered massive galaxy formation 1000 km/s

  48. GN20 z=4.0 EVLA: well sampled velocity field VLA: ‘pseudo-continuum’ 2x50MHz channels

  49. 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

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