1. Radio observations of dust and cool gas in the first galaxies
Chris Carilli (NRAO)
RAS March 2012
Current State-of-Art: host galaxies of z ~ 6 quasars and the early formation of massive galaxies and SMBH
The Future is now! The Atacama Large Millimeter Array and Jansky Very Large Array
Thanks: Wang, Riechers, Walter, Fan, Bertoldi, Menten, Cox
ESO

2. cm to submm diagnostics of galaxy formation
100 Mo yr-1 at z=5
Low J CO emission: total gas mass, dynamics
High density gas tracers (HCN, HCO+)
Synch. + Free-Free = star formation
EVLA and GBT Line
High J molecular lines: gas excitation, physical conditions
Dust continuum = star formation
Atomic fine structure lines: ISM gas coolant

3. SDSS
Apache Point NM
Massive galaxy and SMBH formation at z~6: Quasar host galaxies 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
z=6.42

4. Gunn-Peterson effect toward z~6 SDSS QSOs
0.9um
Gunn-Peterson effect toward z~6 SDSS QSOs
Pushing into the tail-end of cosmic reionization => sets benchmark for first luminous structure formation
GP effect => study of ‘first light’ is restricted to obs > 1um
Fan 05

5. 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
Mdust ~ 1.5 to 5.5 x108 Mo (κ125um = 19 cm2 g-1)

6. Dust formation at tuniv<1Gyr?
AGB Winds > 109yr
High mass star formation? (Anderson, Dwek, Cherchneff, Shull, Nozawa)
‘Smoking quasars’: dust formed in BLR winds/shocks (Elvis, Ilitzur)
ISM dust formation (Draine)
Extinction toward z=6.2 QSO + z~6 GRBs => different mean grain properties at z>4 (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.

7. Under standard model assumptions (Michalowski ea 2011):
AGB stars: insufficient in most instances
SN: sufficient only if no dust destruction

8. Dust heating? Radio to near-IR SED
Star formation
low z QSO SED
TD ~ 1000K
Radio-FIR correlation
FIR excess = 47K dust
SED = star forming galaxy with SFR ~ 400 to 2000 Mo yr-1

9. 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
Accurate host galaxy redshifts
1mJy

10. CO excitation: Dense, warm gas, thermally excited to 6-5
230GHz
691GHz
starburst nucleus
Milky Way
Radiative transfer 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
=> Entire ISM (kpc-scales) ~ GMC SF cloud core! 10

11. LFIR vs L’(CO): ‘integrated K-S Star Formation relation’
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

12. Imaging => dynamics => weighing the first galaxies
z=6.42
0.15” TB ~ 25K
PdBI CO7-6
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

13. Break-down of MBH – Mbulge relation at high z
<MBH/Mbulge> ~ 15 higher at z>4 => Black holes form first?
Caveats:
Better CO imaging (size, i)
Bias for optically selected quasars?
At high z, CO only method to derive Mbulge

14. [CII] 158um search in z > 6.2 quasars
Dominant ISM gas cooling line, tracing CNM and PDRs
[CII] strongest cm to FIR line in SF galaxies ~ 0.1% to 1% LGal
z>4 => FS lines observed in (sub)mm bands; z>6 => Bure! 1”
[CII]
[NII]
S[CII] = 3mJy
S250GHz < 1mJy
L[CII] = 4x109 Lo
S250GHz = 5.5mJy
S[CII] = 12mJy

15. 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

16. [CII] CII/FIR: Large scatter, with possible cut-off at FIR ~ 1012 Lo
SMC
CII/FIR: Large scatter, with possible cut-off at FIR ~ 1012 Lo
lower gas heating efficiency due to charged dust grains in high radiation environments (Malhotra)
Opacity in FIR may also play role (Papadopoulos)
Low metalicity => high CII/FIR: increased UVMFP (Israel ea 2011)

17. [CII] SF gal AGN Stacey ea 2011 High z sources: even larger scatter
SF galaxies: CII/FIR ~ 0.1% to 1%
AGN: CII/FIR < 0.1%

18. Summary: cm/mm observations of 33 quasars at z~6
Only direct probe of the host galaxies
JVLA
160uJy
J CO at z = 5.9
11 in mm continuum => Mdust ~ 108 Mo: Dust formation?
10 at 1.4 GHz continuum: Radio to FIR SED => SFR ~ 1000 Mo/yr
8 in CO => Mgas ~ 1010 (α/0.8) Mo = Fuel for star formation
High excitation ~ starburst nuclei, but on kpc-scales
Follow star formation law: 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

19. Building a giant elliptical galaxy + SMBH at tuniv< 1Gyr
‘Massive-Black’ hydro-simulation ~ 1 cGpc3 (di Matteo ea. 2012)
Stellar mass > 1011 Mo forms via efficient cold mode accretion: SFR ~ gas accretion rate > 100 Mo yr-1
SMBH of ~ 109 Mo forms (first) via steady, Eddington-limited accretion
Evolves into giant elliptical galaxy in massive cluster (1015 Mo) by z=0

20. Building a giant elliptical galaxy + SMBH at tuniv< 1Gyr
Good news: Rapid enrichment of metals, dust in early, massive galaxies
Bad news: Rare, extreme mass objects: ~ 100 SDSS z~6 QSOs on entire sky!
Goal: push to first ‘normal’ galaxies

21. Karl G. Jansky Very Large Array
80x Bandwidth (8 GHz, full stokes), with 4000 channels
5x frequency coverage (continuous 1 to 50 GHz)
10x continuum sensitivity (<1uJy)
Spatial resolution ~ 40mas at 43 GHz

22. Atacama Large Milllimeter Array
High sensitivity array = 54x12m
Wide field imaging array = 12x7m
Frequencies = 80 GHz to 900 GHz
Resolution = 20mas at 800 GHz
Sensitivity = 13uJy in 1hr at 230GHz
ALMA+EVLA represent an order of magnitude, or more, improvement in observational capabilities from 1 GHz to 1 THz!

23. ALMA and first galaxies
100Mo/yr
10Mo/yr
ALMA small FoV (1’ at 90GHz) => still need wide field cameras on large single dishes

24. 8GHz spectroscopy SMG at z~6 in 24hrs
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 = real spectroscopy/astrochemistry
EVLA: 30% FBW, ie.19 to 27 GHz (CO1-0 at z=3.2 to 5.0) => large cosmic volume searches for molecular gas w/o need for optical redshifts

25. First JVLA results: 46GHz, BW=256MHz, FoV = 1’
CO1-0
sBzK z=1.5
CO 2-1 from 3 SMGs z~4.0
CO 1-0 from normal SF galaxy z ~ 1.5
=> Every few hour observation with JVLA at > 20 GHz will discover new galaxies in CO!
z=4.055
4.056
4.051
HST/SUBMM
CO2-1

26. On time and on budget
Early science ApJ special issue: September 2011

27. ALMA status (Jan 2012)
27 Antennas on high-site
54 antennas in Chile
38 front-ends delivered
Early science has begun (8/1 over subscription!)
Full operation by end 2013

28. The VLA Strikes Back!

30. Y J H
≤ z
Bouwens ea 2012
z > 7 Ly-break galaxies
SFR ~ 1 to 10 Mo yr-1
> 1 arcmin-2
Decreasing dust content w. z
X1600A

31. Comparison to low z quasar hosts
z=6 FIR lum quasars
IRAS selected
z=6 stacked mm non-detections
PG quasars

32. EVLA/ALMA Deep fields: 1000hrs, 50 arcmin2, 8GHz BW
Volume (EVLA, z=2 to 2.8) = 1.4e5 cMpc3
1000 galaxies z=0.2 to 6.7 in CO with M(H2) > 1010 (α/3.8) Mo
100 in [CII] z ~ 6.5
5000 in dust continuum
New horizon for deep fields!
Millennium Simulations Obreschkow & Rawlings