1. Observing Molecules in the EoR
Pierre Cox
IRAM
Grenoble, France
October 27, 2006
SKA Workshop, Paris

2. The spectrum of a ULIRG: a `field guide’
Non-thermal radio
Thermal dust
- Dominated luminosity
- Hotter in AGN
- Mid-IR spectral features
(missing in AGN)
Molecular and atomic lines
- mm CO/HCN
- far-IR: C/N/O
- mid-IR: C-C/C=C/H2
Luminosities involved:
3x1011 <L/Lsun< 1014
From Blain (2003)
October 27, 2006
SKA Workshop, Paris

3. October 27, 2006
SKA Workshop, Paris

4. LVG solution Cloverleaf
CO LVG solution:
Disk radius: 1 kpc
excellent agreement with lens models !
log(n(H2)) = 4.2 cm-3
Tkin = 30 K
M(H2) = M
L’CO(1-0) = K km/s pc2
Xco = 1.8 M/ K km/s pc2
Weiss et al. (2005)

5. Subarcsecond Imaging Results
< 0.5” (4 kpc)
 Compact sources
Scaled-up versions and
more gas-rich of the local
ULIRG population
Central densities and
potential well depths
comparable to those of
elliptical galaxies or
massive bulges
Fulfill the criteria of maximal starbursts: initial
gas reservoir Msun is converted to stars on a timescale ~3-10 tdyn or a few 108 yr
Tacconi, Neri, Chapmanm Genzel et al. (2006)
October 27, 2006
SKA Workshop, Paris

6. J1148+5251 - The Most Distant QSO at z=6.42
Observing First Light at Radio Wavelengths
Gunn Peterson trough
Fan et al. 2003; White et al. 2003
z-band (Keck – Djorgovski et al.)
z=6.42; age~870 Myr
one of the first luminous sources
MBH ~ 1-5 x 109 Msun (Willot et al. 2003)
Mdust ~ 108 Msun (Bertoldi et al. 2003)
October 27, 2006
SKA Workshop, Paris
Dust continuum at 1.2 mm

7. CO(3-2) 46.6149 GHz PdBI continuum VLA Walter et al. 2003
Bertoldi et al. 2003
October 27, 2006
SKA Workshop, Paris

8. Mass: MH2 = 2 x 1010 Msun Mdyn = 3 x 109 sin-2(i) Msun
Mass in C and O: ~3x107 Msun
CO excitation in J (filled circles), compared to NGC 253 (dashed)
LVG Model:
Tkin= 100K, nH2=7x104 cm-3
Bertoldi et al. (2003)
October 27, 2006
SKA Workshop, Paris

9. Resolving the CO emission in J1148+5251
VLA A+B + C array; res.: 0.15” (~1 kpc)
Two sources separated by 0.3”
(1.7 kpc at z=6.4) containing each
5 x 109 Msun
Not likely to be amplified
If gravitationally bound,
MDyn=4.5x1010 Msun
CO 3-2 at 45GHz 1”
Early enrichment of heavy elements (z_sf > 8)
Integration times: hours to days on HLIRGs
Walter et al. 2004
October 27, 2006
SKA Workshop, Paris

10. [[CII] 158 microns and [CI] emission lines in J1148+5251 at z=6
[[CII] 158 microns and [CI] emission lines in J at z=6.42 Probing the physics of a PDR at the end of the re-ionisation epoch
CO(7-6)
CII
CI(1-0)
October 27, 2006
SKA Workshop, Paris

11. Other High Density Tracer: HCN, HNC and HCO+
APM (z=3.91)
HCO+(5-4)
HNC(5-4)
HNC(5-4) & CN(5-4)
L’(HCO+) = 4 x 1010 K/(km/s pc2)
HCO+(5-4)/HCN(5-4) ~ 1
HNC(5-4)/HCN(5-4) ~ 0.9
Wagg et al. 2005; Burillo et al. 2006; Guelin, Salome et al. 2006
October 27, 2006
SKA Workshop, Paris

12. ALMA/EVLA/GBT Redshift coverage for CO
Epoch of Reionization
VLA CO(3-2), PdBI
CO 6-5, 7-6 in
z=6.42
Other lines: HCN, HCO+, CI, CII, H2O
October 27, 2006
SKA Workshop, Paris

13. SKA and CO
M 82
October 27, 2006
SKA Workshop, Paris

14. SKA and ALMA: Optimal CO searches
SKA/ALMA – comparable speed at 22 GHz, SKA clearly faster at 43 GHz (FoV, fractional bandwidth, sensitivity)
SKA/ALMA – complementary: high vs. low order transitions
October 27, 2006
SKA Workshop, Paris

15. Complementarity: Line sensitivity
z=5
SFR=10M_sun/yr
High order, C+…
Low order transitions
October 27, 2006
SKA Workshop, Paris

16. Radio studies of the first luminous objects
Radio Continuum studies of star forming galaxies
1e13 L_sun
1e12 L_sun
1e11 L_sun
CO (+other molecules) at z>4
VLA: 3s in 3 hrs for L_FIR = 1e13 M_sun (‘HLIRG’)
SKA (20 – 40 GHz): 3s in 3hrs for L_FIR =1e11 M_sun (‘LIRG’)
October 27, 2006
SKA Workshop, Paris

17. Complementarity: continuum sensitivity
AGN, star formation
dust
Stars, ionized gas
October 27, 2006
SKA Workshop, Paris

18. SKA into the EoR: Low Order Molecular Lines, Star Formation
: Hyperluminous IR galaxies
Detect low order CO emission in seconds, including imaging on subkpc scales.
Detect high dipole moment molecules (HCO+, HCN…) in minutes (critical densities > 1e5 cm^-3).
Image non-thermal emission associated with star formation and/or AGN at mas resolution.
Studying 1st galaxies
Detect ‘normal’ (eg. Ly a), star forming galaxies, like M51, at z>6, in few hours
Determine redshifts directly from molecular lines
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.
z=6.55
SFR>10 M_sun/yr
October 27, 2006
SKA Workshop, Paris

19. The Future (is now): Probing the EoR!
Study physics of the first luminous sources
This can only be done at near-IR to radio wavelengths
Currently limited to ‘pathological’ systems (HLIRGs)
SKA and ALMA more sensitive which is critical for the study of ‘normal’ galaxies
z=6.4
October 27, 2006
SKA Workshop, Paris