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ALMA, EVLA, and the Origin of Galaxies (Dense Gas History of the Universe) Chris Carilli (NRAO) Bonn, Germany, September 2010. The power of radio astronomy: dust, cool gas, and star formation Current State-of-Art z ~ 6: Quasar host galaxies = early formation of massive galaxies and SMBH

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  1. ALMA, EVLA, and the Origin of Galaxies (Dense Gas History of the Universe) Chris Carilli (NRAO) Bonn, Germany, September 2010 • The power of radio astronomy: dust, cool gas, and star formation • Current State-of-Art • z ~ 6: Quasar host galaxies = early formation of massive galaxies and SMBH • z ~ 1 to 3: Normal galaxy formation during the epoch of galaxy assembly = probing the ‘Gas Rich Universe’ • Bright (near!) future: The Atacama Large Millimeter Array (and CCAT!) and Expanded Very Large Array – recent example! • Thanks: Wang, Riechers, Walter, Fan, Bertoldi, Menten, Cox, Daddi, Schinnerer, Pannella, Aravena, Smolcic, Neri, Dannerbauer… ESO

  2. Star formation history of the Universe (mostly optical view) First light + cosmic reionization ‘epoch of galaxy assembly’ ~50% of present day stellar mass produced between z~1 to 3 Bouwens +

  3. Star formation as function of stellar mass ‘active star formation’ specific SFR = SFR/M*~ e-folding time-1 tH-1 ‘red and dead’ Zheng ea ‘Downsizing’: Massive galaxies form most of stars quickly, at high z (see also: stellar pop. synthesis at low z; evolved galaxies at z ~1 to 2)

  4. Optical Limitation 1: Dust • Dust correction in UV • Factor 5 at z < 4 • No correction at z > 6 ? Bouwens +

  5. Optical Limitation 2: Cold gas = fuel for star formation (‘The missing half of galaxy formation’) Integrated Kennicutt-Schmidt star formation law: relate SFR and gas content of galaxies Low and high z starbursts Power-law index = 1.5 Low z spirals ‘SFR’ ‘Mgas’

  6. Millimeter through centimeter astronomy: unveiling the cold, obscured universe GN20 z=4 submm galaxy Wilson et al. CO image of ‘Antennae’ merging galaxies CO HST/CO/SUBMM • cm/mm reveal the dust-obscured, earliest, most active phases of star formation in galaxies • cm/mm reveal the cool gas that fuels star formation

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

  8. Spectral lines • Molecular gas • CO = total gas mass tracer • M(H2) = α L’(CO(1-0)) • Velocities => dyn. mass • Gas excitation => ISM physics (densities,temperatures) • Astrochemistry/biology, eg. dense gas tracers (HCN) directly associated with star formation (Smail, van Dishoeck) • Gas supply: smooth accretion or major gas rich mergers? submm cm z=0.2 Atomic fine structure lines Molecular rotational lines z=4

  9. Fine Structure lines [CII] 158um (2P3/2 - 2P1/2) • Principal ISM gas coolant: photo-electric heating by dust • Traces star forming regions and the CNM • [CII] most luminous line from meter to FIR, up to 1% Lgal • Herschel: revolutionary look at FSL in nearby Universe – AGN/star formation diagnostics (Hailey-Dunsheath) Fixsen et al. [CII] CO [OI] 63um [CII] [OIII]/[CII] [OIII] 88um [CII] Cormier et al.

  10. MAMBO at 30m (Cox) 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”

  11. SDSS Apache Point NM Theme I: Massive galaxy and SMBH formation at z~6 – Quasar hosts at tuniv<1Gyr • Why quasars? • Rapidly increasing samples: z>4: > 1000 known z>5: > 100 z>6: 20 • Spectroscopic redshifts • Extreme (massive) systems: Lbol ~1014 Lo=> MBH~ 109 Mo => Mbulge~ 1012 Mo • Downsizing: study of very early massive galaxy formation intrinsically interesting 1148+5251 z=6.42

  12. Dust in high z quasar host galaxies 30% of z>2 quasars have S250 > 2mJy MAMBO 30m 250GHz surveys HyLIRG Wang sample 33 z>5.7 quasars • LFIR ~ 0.3 to 1.3 x1013 Lo (~ 1000xMilky Way) • Mdust ~ 1.5 to 5.5 x108Mo • Dust formation at tuniv<1Gyr? AGB Winds ≥ 1.4e9yr • High mass star formation? (Dwek, Anderson, Cherchneff, Shull, Nozawa, Valiante)

  13. 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

  14. 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 • Accurate host galaxy redshifts 1mJy

  15. CO excitation: Dense, warm gas, thermally excited to 6-5 230GHz 691GHz (Papadopoulos, Smail) 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

  16. LFIR vs L’(CO): 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 SFR 1e3 Mo/yr Index=1.5 MW 1e11 Mo Mgas

  17. Imaging => dynamics => weighing the first galaxies z=6.42 0.15” TB ~ 25K PdBI CO3-2 VLA -150 km/s 7kpc 1” ~ 5.5kpc + +150 km/s • Size ~ 6 kpc, with two peaks ~ 2kpc separation • Dynamical mass (r < 3kpc) ~ 6 x1010 Mo • M(H2)/Mdyn ~ 0.3

  18. Break-down of MBH – Mbulge relation at very high z (Maiolino) z>4 QSO CO z<0.2 QSO CO Low z galaxies • ‘Causal connection between galaxy and SMBH formation’ • At high z, CO only method to derive Mbulge MBH ~ 0.002Mbulge <MBH/Mbulge> ~ 15 higher at z>4 => Black holes form first?

  19. Fine Structure Lines: [CII]158um search in z > 6.2 quasars [CII] 1” [NII] For z>6 => redshifts to 250GHz => Bure! (Knudsen) • 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

  20. 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

  21. Theme I 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 • Departure from MBH – Mbulge at z~6: BH form first? • 3 in [CII] => maximal star forming disk: 1000 Mo yr-1 kpc-2

  22. Building a giant elliptical galaxy + SMBH at tuniv< 1Gyr (‘extreme downsizing’) 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 high redshift

  23. Theme II: ‘Normal’ star forming galaxies during epoch of galaxy assembly (‘sBzK’ at z ~ 2) HST • HST imaging => disk sizes ~ 1” ~ 8kpc, punctuated by massive star forming regions • color-color diagrams identify thousands of z~ 2 star forming galaxies • near-IR selected => ‘stellar mass limited sample’: M* ~ 1010 to 1011Mo • Common ~ few x10-4 Mpc-3 (5 arcmin-2)

  24. Unbiased star formation rates in z~2 sBzK VLA 1.4GHz stacking: 30,000 in COSMOS (Decarli) • COSMOS 2 deg2 Deep Field (Scoville ea) • Approaching SDSS volume at z > 1 • 2e6 galaxies from z~ 0 to 7 <S1.4> = 8.8 +/- 0.1 uJy • <SFR> = 96 Mo yr-1 [FIR ~ 3e11 Lo] • VLA size ~ 1” ~ HST Pannella +

  25. Stacking in bins of 3000 1010 Mo 3x1011 Mo • SFR ~ independent of blue magnitude • SFR increases with B-z => dust extinction increases with SFR (or M*) • SFR increases with stellar mass

  26. Dawn of Downsizing: SFR/M* vs. M* (Karim) 1.4GHz SSFR • SSFR constant with M*, unlike z<1=> ‘pre-downsizing’ ~ constant efolding time • z>1.5 sBzK well above the ‘red and dead’ galaxy line => even large growing exponentially • UV dust correction = f(SFR, M*) [factor 5 at 2e10 Mo ~ LBG (Shapely+ 01)] z=2.1 z=1.5 5x tH-1 (z=1.8) z=0.3 UV SSFR

  27. CO observations with Bure: Massive gas reservoirs without extreme starbursts (Daddi ea 2009) • 6 of 6 sBzK detected in CO • Gas mass ~ 1011 Mo ~ gas masses in high z HyLIRG • but • SFR < 10% HyLIRG • Gas masses ≥ stellar masses => pushed back to epoch when galaxies are gas dominated!

  28. Closer to Milky Way-type gas conditions (Dannerbauer) HyLIRG 1.5 1 • Lower CO excitation: low J observations are key! • FIR/L’CO: Gas consumption timescales >= few x108 yrs

  29. Summary Theme II: Probing the Gas Rich Universe = Gas dominated, normal galaxy formation at z ~2 Genzel + 08 • SSFR constant with M*: ‘pre-downsizing’ • Well above ‘red + dead’ curve up to 1011 M* • Gas masses ~ 1011 Mo ≥ stellar masses • Gas consumption time > few x108 yrs • ‘Secular (spiral) galaxy formation during epoch of galaxy assembly’ • Great promise for ALMA + EVLA!

  30. (Testi) What is ALMA? Tenfold improvement (or more), in all areas of (sub)mm astronomy, including resolution, sensitivity, and frequency coverage. • antennas: 54x12m, 12x7m antennas • frequencies: 80 GHz to 720 GHz • res = 20mas res at 700 GHz • rms = 13uJy in 1hr at 230GHz • What is the EVLA? similar ten-fold improvement in most areas of cm astronomy • frequencies = 1 to 50 GHz • 8 GHz BW => 80x old • res = 40mas res at 43GHz • rms = 6uJy in 1hr at 30GHz ALMA+EVLA ~ Order magnitude improvement from 1GHz to 1 THz!

  31. Pushing to normal galaxies 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 EVLA 1.4 GHz continuum: thousands of sBzK galaxies

  32. ALMA and first galaxies: [CII] 100Mo/yr 10Mo/yr ALMA ‘redshift machine’: [CII] in z>7 dropouts

  33. Wide bandwidth spectroscopy J1148+52 at z=6.4 in 24hrs with ALMA • ALMA: Detect multiple lines, molecules per 8GHz band = real astrochemistry • 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

  34. 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 5 antennas on high site EVLA Status • Antenna retrofits 70% complete (100% at ν ≥ 18GHz). • Early science in March 2010 using new correlator (2GHz) • Full receiver complement completed 2012 + 8GHz

  35. 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 +250 km/s 0.4mJy • SFR ~ 103 Mo/year • Mgas ~ 1011 Mo • Early, clustered massive galaxy formation 1000 km/s -250 km/s

  36. Dense gas history of the Universe  Tracing the fuel for galaxy formation over cosmic time SF Law SFR Millennium Simulations Obreschkow & Rawlings Mgas Primary goal for studies of galaxy formation in next decade!

  37. EVLA/ALMA Deep fields: the‘missing half’ of galaxy formation • 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 Millennium Simulations Obreschkow & Rawlings

  38. END ESO

  39. CCAT: wide field ‘finder’ surveys

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