ESO

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

Millimeter through centimeter astronomy: unveiling the cold, obscured universe

GN20 SMG z=4.0

Galactic

Submm = dustoptical 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

Cosmic ‘Background’ Radiation

Franceschini 2000

Over half the light in the Universe is absorbed and reemitted in the FIR

30 nW m-2 sr-1

17 nW m-2 sr-1

Radio – FIR: obscuration-free estimate of massive star formation

Radio: SFR = 10-21 L1.4 W/Hz

FIR: SFR = 3x10-10 LFIR (Lo)

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

obs = 250 GHz

1000 Mo/yr

Spectral lines

Molecular rotational lines

Atomic fine structure lines

z=0.2

z=4

cm submm

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

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] 88um [CII][OIII]/[CII]

Cormier et al.

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

MB < -26 =>

Lbol > 1014 Lo

MBH > 109 Mo (Eddington / MgII)

1148+5251 z=6.42

SDSSApache Point NM

Gunn Peterson trough => pushing into cosmic reionization = first galaxies, black holes

First galaxies and SMBH: z>6 => tuniv < 1 Gyr

1148+5251 z=6.42

QSO host galaxies – MBH -- Mbulge relation

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)

Haaring & Rix

Nearby galaxies

Cosmic Downsizing

Massive galaxies form most of their stars rapidly at high z

tH-1tH-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

• 30% of z>2 quasars have S250 > 2mJy

• LFIR ~ 0.3 to 1.3 x1013 Lo (~ 1000xMilky Way)

• Mdust ~ 1.5 to 5.5 x108 Mo

HyLIRG

Dust in high z quasar host galaxies: 250 GHz surveys

Wang sample 33 z>5.7 quasars

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

Stratta et al.

z~6 quasar, GRBs

Galactic

SMC, z<4 quasars

Dust heating? Radio to near-IR SED

TD = 47 K FIR excess = 47K dust

SED consistent with star forming galaxy:

SFR ~ 400 to 2000 Mo yr-1 Radio-FIR correlation

low z SED

TD ~ 1000K

Star formation?

AGN

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/s1mJy

CO excitation: Dense, warm gas, thermally excited to 6-5

• 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

Milky Way

starburst nucleus

230GHz 691GHz

LFIR vs L’(CO): ‘integrated Kennicutt-Schmidt star formation law’

Index=1.5

1e11 Mo

1e3 Mo/yr

• Further circumstantial evidence for star formation

• Gas consumption time (Mgas/SFR) decreases with SFRFIR ~ 1010 Lo/yr => tc~108yrFIR ~ 1013 Lo/yr => tc~107yr

=> Need gas re-supply to build giant elliptical

SFR

Mgas

MW

1148+52 z=6.42: VLA imaging at 0.15” resolution

IRAM

1” ~ 6kpc

CO3-2 VLA

‘molecular galaxy’ size ~ 6 kpc

Double peaked ~ 2kpc separation, each ~ 1kpc

TB ~ 35 K ~ starburst nuclei

+0.3”

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

Gas dynamics => ‘weighing’ the first galaxies

z=6.42

-150 km/s

+150 km/s

7kpc

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?

For z>6 => redshifts to 250GHz => Bure!

1”

[CII]

[NII]

[CII] 158um search in z > 6.2 quasars

•L[CII] = 4x109 Lo (L[NII] < 0.1L[CII] )

•S250GHz = 5.5mJy

•S[CII] = 12mJy

• S[CII] = 3mJy

• S250GHz < 1mJy=> don’t pre-select on dust

1148+5251 z=6.42:‘Maximal star forming disk’

• [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

PdBI 250GHz 0.25”res

[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…

[CII]

• 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…

z >4

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

J1425+3254 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 tuniv< 1Gyr

Multi-scale simulation isolating

most massive halo in 3 Gpc3

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

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+

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 Mo yr-1 at z=5

ALMA and first galaxies: [CII] and Dust

100Mo/yr

10Mo/yr

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 (1 beam = 104 cMpc3)

J1148+52 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

EVLA Early Science Results: GN20 molecule-rich proto-

cluster at z=4

4.051

z=4.055

4.052

0.7mJyCO2-1 46GHz

0.4mJy

1000 km/s

GN20z=4.0

+250 km/s

-250 km/s

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

END

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 1st galaxy formation

100 Mo yr-1 at z=5

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(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