1. The Formation and Evolution of SMGs: A (mostly) Panchromatic View
Desika Narayanan
Harvard-Smithsonian Center for Astrophysics
The Team:
Chris Hayward
T.J. Cox
Josh Younger
Patrik Jonsson
Lars Hernquist
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2. Desika Narayanan EVLA Conference
Discovery History
Barger et al., Hughes et al.
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3. The Incredible Fluxes of SMGs:
Median Redshift z~2.4 (Chapman et al 2004)
Selected at S850 > 5 mJy, seen up to S850 ~ 20 mJy
z~2.4
~mJy source
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(NED; Benford 1999)

4. Where We’re at with SMGs:
Median Redshift z~2.4 (peak of cosmic BH and SFR activity)
Chapman et al though see recent z>4 detections by J. Younger et al.
LIR > 1013 L
SFR ~ M/yr
Huge Masses:
DM: 5x1012 M (Blain et al. 2004)
H2: Gas rich ~1010 M(Greve et al., Tacconi et al.)
Stellar: ~1011 M (Swinbank et al., Lonsdale et al.)
Similar to z~2 QSOs
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5. Where We’re at with SMGs:
Median Redshift z~2.4 (Chapman et al 2004)
Selected at S850 > 5 mJy, seen up to S850 ~ 20 mJy
Huge Masses:
DM: 5x1012 M (Blain et al. 2004)
H2: Gas rich ~1010 M(Greve et al., Tacconi et al.)
Stellar: ~1011 M (Swinbank et al., Lonsdale et al.)
SFR~ 2000 M/yr
SMGs are the most luminous, heavily star forming galaxies at the epoch of peak galaxy formation
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6. The Theoretical Challenge (how do we catch up to the observers?):
What is a physical model for SMGs (how do we form them)?
How do they fit in an evolutionary scenario for hierarchical galaxy formation? (aka, how do we connect
them to quasars?)
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7. Clues for the Modelers: Physical Parameters
massive galaxies (~few x 1011 M in stars)
Merger? Disks? +
Tacconi et al. 2008
Lonsdale et al. 2008
= 5-20 mJy SMGs?
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8. Clues for the Modelers:
Huge CO Line Widths:
(800 km/s : (maybe) ~ twice z~2 QSOs)
Off MBH-M* Relation?
(Alexander et al. 2008)
(Greve et al. 2004, Carilli & Wang 2006)
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9. The Theoretical Challenge (how do we catch up to the observers?):
What is a physical model for SMGs (how do we form them)?
How do they fit in an evolutionary scenario for hierarchical galaxy formation?
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10. The Theoretical Challenge: Forming SMGs
What is a physical model for SMGs (how do we form them)?
Numerical Models:
Merger models, diffuse ISM
SAMs:
Flat IMF: dn/dln(m) ~ m 
S850--->
Time--->
S850--->
(Baugh et al. 2004, Swinbank et al. 2008)
(Chakrabarti et al. 2006)
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11. GADGET (SPH) + SUNRISE (IR)+ Turtlebeach (Molecular Line)
Physics Included in Hydrodynamics:
-Full numerics: DM, Gas, Stars and BHs
-Multi-phase McKee-Ostriker ISM
Star formation follows KS relations
BH growth and associated AGN feedback
Supernovae pressurization of ISM
-Virial Properties of Galaxy disks scaled to z~3
-Mergers and Isolated disks simulated
-Halo Masses: 1-5 x 1012 M
Springel et al. ( )
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12. Desika Narayanan EVLA Conference
Narayanan et al. 2008
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13. GADGET (SPH) + SUNRISE (IR) + Turtlebeach (Molecular Line)
Diffuse ISM
GMC
Physics Included in Monte Carlo IR RT:
-IR transfer of stellar and AGN spectrum
(starburst 99 for stars and Hopkins+ 07 for AGN)
-dust radiative equilibrium
-Kroupa IMF, MW Dust to Metals (0.4)
-Stellar Clusters surrounded by placental GMCs (covering fraction is free parameter;
fcover=0.3-1 measured in ULIRGs)
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14. GADGET (SPH) + SUNRISE (IR) + Turtlebeach (Molecular Line)co co co co co co co
Narayanan et al. (2008) co
Physics Included in Monte Carlo CO RT
-Mass spectrum of GMCs included as SISs
-Molecular statistical equilibrium
(collisions and radiation)
-Pressure-driven H2 formation/destruction
(Blitz & Rosolowsky 2006)
-Milky Way Abundances for CO
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15. SMGs are Major Mergers at z~2
Opacity dominated by
birth clouds during
starburst
Opacity dominated by
diffuse dust during inspiral
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Narayanan, Hayward, Cox et al. in prep.
Narayanan, Hayward, Cox, Younger et al. submitted

16. SMGs are Major Mergers at z~2
Low luminosity (~5 mJy)
SMGs are smaller scale (~ M/yr)
starbursts.
The most luminous (~20 mJy) SMGs
are “maximal” high mass starbursts during
final coalesence.
Individual Spirals will have trouble
reproducing anything except very low
luminosity SMGs.
Opacity dominated by
birth clouds during
starburst
Opacity dominated by
diffuse dust during inspiral
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Narayanan, Hayward, Cox et al. in prep.
Narayanan, Hayward, Cox, Younger et al. submitted.

17. Model SED at z=2: Matching Observations
Pope et al. (2006)
Kovacs et al. (2006)
Narayanan, Hayward, Cox, Younger et al. submitted
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18. The Theoretical Challenge:
What is a physical model for SMGs (how do we form them)?
How do they fit in an evolutionary scenario for hierarchical galaxy formation? Are SMGs and quasars related?
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19. The life of an SMG: Sub-mm, CO and B-band evolution√2
Narayanan, Cox, Hayward, Younger et al. in prep.
Sub-mm Flux
B-band Flux
Coppin et al. 2008
virial = 225 km/s * =
530 km/s FWHM
escape ~ 225 km/s * * √2 =
750 km/s FWHM
Narayanan, Hayward, Cox et al. in prep.
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20. The Connection between SMGs and QSOs
Sub-mm Flux
B-band Flux
Time Scale between
peak SMG phase and
peak QSO phase: ~50 Myr -
though note tons of overlap
Narayanan, Hayward, Cox et al. in prep.
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21. The MBH-M* Relation in SMGs and Quasars: Observed
Alexander et al.
Quasars
Shileds et al.
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22. The MBH-M* Relation in SMGs and Quasars: Modeled
Time
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23. The Trip Toward the Magorrian Relation: SMGs
Models
(DN, Hayward, Cox, Younger et al.)
Observations (Alexander et al.)
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24. Are High-z QSOs on the MBH-M* relation ?
Quasars at z~6
Walter, Carilli et al.
~120 km/s 
Quasars at z~2
Shields et al. 2006
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25. CO FWHM-QSO Luminosity Relation
Optically Luminous LOSs have small CO FWHMs because of molecular disk formation
Narayanan, Li et al. (2008)
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Line widths of lower
luminosity z~6 quasars
Are observed to be broader
(~600 km/s), consistent with
large halo mases
Carilli et al. (2007)
Maiolino et al. (2007)
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27. Desika Narayanan EVLA Conference
Potential Contribution from the eVLA: Morphologies of SMGs (does our merger-driven scenario work in real life?)
Sub-mm flux
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28. Contribution from the EVLA: True Line Width Distribution of QSOs
Sub-mm flux
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Conclusions
Merger-driven model can reproduce S mJy using only observationally motivated physical parameters
Sub-mm duty cycles, SEDs, CO fluxes and line widths naturally reproduced in a merger-driven model
SMGs evolve naturally into QSOs and then onto Magorrian Relation
Quasars may be selected to have face-on molecular disks
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30. QSOs may have preferentially face-on disks
Coppin et al. 2008
QSOs
Sub-mm Flux
SMGs
Narayanan, Hayward, Cox et al. in prep.
Narayanan et al. 2008
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31. GADGET (SPH) + SUNRISE (IR) + Turtlebeach (Molecular Line)
Physics Included in Monte Carlo IR RT:
-IR transfer of stellar and AGN spectrum
(starburst 99 for stars and Hopkins+ 07 for AGN)
-dust radiative equilibrium
-Kroupa iMF, MW Dust to Gas
-Stellar Clusters surrounded by placental GMCs (covering fraction is free parameter)
Diffuse ISM
GMC
z = 2.5 SED input
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