ESO Radio observations of the formation of the first galaxies and supermassive Black Holes Chris Carilli (NRAO) Notre Dame Astrophysics March 30, 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
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 formation HST/CO/SUBMM
Radio – FIR: obscuration-free estimate of massive star formation Radio: SFR = L 1.4 W/Hz FIR: SFR = 3x L FIR (L o )
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
Spectral lines: centimeter through submm Molecular rotational lines Atomic fine structure lines z=0.2 z=4
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
Fine Structure lines [CII] 158um ( 2 P 3/2 - 2 P 1/2 ) Principal ISM gas coolant Traces star formation and the CNM COBE: [CII] 10x more luminous than any other cm to FIR line in the Galaxy ~ 1% L gal
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
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 > L o M BH > 10 9 M o (Eddington / MgII) z=6.42 SDSS Apache Point NM
Gunn Peterson trough => pushing into cosmic reionization = first galaxies, black holes First galaxies and SMBH: z>6 => t univ < 1 Gyr z=6.42
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
Cosmic Downsizing Massive galaxies form most of their stars rapidly, and at high redshift t H -1 Currently active star formation Red and dead => Require active star formation at early times Zheng+
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
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 ) 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 Stratta et al. z~6 quasar, GRBs Galactic SMC, z<4 quasars
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
Fuel for star formation? Molecular gas: 8 CO detections at z ~ 6 with PdBI, VLA M(H 2 ) ~ 0.7 to 3 x10 10 M o Δv = 200 to 800 km/s 1mJy
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
L FIR vs L’(CO): ‘integrated Kennicutt-Schmidt star formation law’ Index=1.5 1e11 M o 1e3 M o /yr Further evidence for star formation Gas consumption time (M gas /SFR) decreases with SFR FIR ~ L o /yr => t c ~10 8 yr FIR ~ L o /yr => t c ~10 7 yr => Need gas re-supply to build giant elliptical SFR M gas MW
z=6.42: VLA imaging at 0.15” resolution IRAM 1” ~ 5.5kpc CO3-2 VLA ‘molecular galaxy’ size ~ 6 kpc Double peaked ~ 2kpc separation, each ~ 1kpc T B ~ 35 K ~ starburst nuclei + 0.3”
CO only method for deriving dynamical masses at these distances Dynamical mass (r < 3kpc) ~ 0.4 to 2 x10 11 M o M(H 2 )/M dyn ≥ 0.1 to 0.5 Gas dynamics => ‘weighing’ the first galaxies z=4.19z= km/s +150 km/s
Break-down of M BH -- M bulge relation at very high z High z QSO CO Low z QSO CO Low z galaxies Riechers + = 15 higher at z>4 => Black holes form first?
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
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 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
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 ~ M o : Fuel for star formation in galaxies High excitation ~ starburst nuclei 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 Confirm decrease in R NZ with increasing z J CO at z = 5.9 Summary cm/mm observations of 33 quasars at z~6: only direct probe of the host galaxies J1048 z=6.23 CO w. PdBI, VLA
Building a giant elliptical galaxy + SMBH at t univ < 1Gyr 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= 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+
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) 40mas resolution at 40GHz Overall: ALMA+EVLA provide > order magnitude improvement from 1GHz to 1 THz!
(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
ALMA and first galaxies 100M o /yr 10M o /yr ALMA small FoV (1’ at 90GHz) => still need wide field cameras on large single dishes
Wide bandwidth spectroscopy ALMA: Detect multiple lines, molecules per 8GHz band EVLA 28 to 36 GHz = CO2-1 at z=5.3 to 7.2=> large cosmic volume searches (1 beam = 5000 Mpc 3 ) J at z=6.4 in 24hrs with ALMA
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 CH stimulated emission at z=0.9 by GMC in lensing galaxy toward %
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 Q embargoed first light image
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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
Cosmic ‘Background’Radiation Franceschini 2000
Comparison to low z quasar hosts IRAS selected PG quasars z=6 quasars Stacked mm non-detections Hao et al. 2005
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
[CII] [CII]/FIR decreases with L FIR = lower gas heating efficiency due to charged dust grains => luminous starbursts are still hard to detect in C+ Normal star forming galaxies are not much harder to detect HyLIRG at z> 4: no worse than low z ULIRG Don’t pre-select on dust Malhotra, Maiolino, Bertoldi, Knudsen, Iono, Wagg… z >4