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Radio observations of the formation of the first galaxies and supermassive Black Holes Chris Carilli (NRAO) Purple Mountain Observatory, May 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) Purple Mountain Observatory, May 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 • Bright (and near!) future: Atacama Large Millimeter Array and the Expanded Very Large Array • 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 and reemitted in the FIR Franceschini 2000

  4. Radio – FIR: obscuration-free estimate of massive star formation • Radio: SFR = 10-21 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

  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 [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. First galaxies and SMBH: z>6 => tuniv < 1 Gyr Gunn Peterson trough => pushing into cosmic reionization = first galaxies, black holes 1148+5251 z=6.42

  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) • Extinction toward z=6.2 QSO and z~6 GRBs => different mean grain properties (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 • 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) ~ 0.4 to 2 x1011 Mo • M(H2)/Mdyn ≥ 0.1 to 0.5 => gas/baryons dominate inner few kpc

  22. 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?

  23. [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

  24. 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 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

  25. [CII] • [CII]/FIR decreases with LFIR = lower gas heating efficiency due to charged dust grains => luminous starbursts are still hard to detect in [CII] • Opacity in FIR may also play role (Papadopoulos) Malhotra, Maiolino, Bertoldi, Knudsen, Iono, Wagg…

  26. [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 Malhotra, Maiolino, Bertoldi, Knudsen, Iono, Wagg…

  27. Summary cm/mm observations of 33 quasars at z~6: only direct probe of the host galaxies J1425+3254 CO at z = 5.9 J1048 z=6.23 CO w. PdBI, VLA • 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 • Follow star formation law (LFIR vs L’CO): tc ~ 107 yr • 3 in [CII] => maximal star forming disk: 1000 Mo yr-1 kpc-2 • Confirm decrease in RNZ with increasing z

  28. Building a giant elliptical galaxy + SMBH at tuniv< 1Gyr 10 • 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

  29. 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.

  30. 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

  31. 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) • 40mas resolution at 40GHz Overall: ALMA+EVLA provide > order magnitude improvement from 1GHz to 1 THz!

  32. 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

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

  34. 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 (1 beam = 104 cMpc3)

  35. EVLA Status • Antenna retrofits 70% complete (100% at ν ≥ 18GHz). • Early science in March 2010 using new correlator (2GHz) • Full receiver complement completed 2012 with 8GHz bandwidth

  36. EVLA Early Science Results: GN20 molecule-rich proto-cluster at z=4 z=4.055 4.051 4.052 0.4mJy 0.7mJy CO2-1 46GHz 1000 km/s

  37. GN20 z=4.0 +250 km/s -250 km/s

  38. ALMA Status • Antennas, receivers, correlator in production: best submm receivers and antennas ever! • Site construction well under way: Observation Support Facility, Array Operations Site, 3 Antenna interferometry at high site! • Early science call Q1 2011 embargoed first light image

  39. END

  40. 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

  41. Comparison to low z quasar hosts z=6 quasars IRAS selected Stacked mm non-detections PG quasars Hao et al. 2005

  42. 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

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