1. Purple Mountain Observatory, May 2010
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 = 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 cm submm z=0.2 z=4 Atomic fine structure lines
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. Powerful suite of existing cm/mm facilites
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. Massive galaxy and SMBH formation at z~6: gas, dust, star formation in quasar hosts
SDSS
Apache Point NM
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)
z=6.42

11. First galaxies and SMBH: z>6 => tuniv < 1 Gyr
Gunn Peterson trough => pushing into cosmic reionization = first galaxies, black holes
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 x108 Mo

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
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 18

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
For z>6 => redshifts to 250GHz => Bure! 1”
[CII]
[NII]
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

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. Malhotra, Maiolino, Bertoldi, Knudsen, Iono, Wagg…
[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. Malhotra, Maiolino, Bertoldi, Knudsen, Iono, Wagg…
[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
J 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< 1Gyr10
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
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
J at z=6.4 in 24hrs with ALMA
If one placed CO 6-5 in the LSB, one would get the line of H2O and the 7-6 line of 13CO, in addition to several H2CO lines, in the USB.
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
4.051
4.052
0.7mJy
CO2-1 46GHz
0.4mJy
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. (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
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

43. 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