1. Kinemetry of High-Redshift Galaxies
Distinguishing Rotating Disks from Major Mergers
Kristen Shapiro and the SINS team:
R. Genzel, N.M. Förster Schreiber, L.J. Tacconi, F. Eisenhauer, N. Bouché, D. Lutz,
R. Davies, G. Cresci, S. Genel, E. Hicks, R. Bender, S. Seitz, A. Verma,
M. Lehnert, N. Nesvadba, A. Sternberg, R. Ivison, F. Bertoldi, A. Blain, S. Chapman,
P. Cox, T. Greve, R. Neri, A. Omont, I. Smail, D. Erb, A. Shapley, C. Steidel, A. Cimatti, E. Daddi, A. Renzini, V. Mignoli, N. Arimoto, X. Kong

2. The SINS Survey rotation dispersion dominated merger 1 (8 kpc)70
-70
D3a 4751 (2.27)
SA (2.3)
-50 30 35
-20
BX 502 (2.16)
BX 405 (2.03)
-35 40
-30
BM 1163 (1.41)
BX 404 (2.03) -5
merger
-60
K20-6 (2.2)
-80
100
BX 599 (2.33)
GK 167 (2.58)
GK2252 (2.41)
-280
280
BX389 (2.2)
170
K20-5 (2.2)
-170
-120
120
D3a 7144 (1.7)
150
SA (1.51)
-100 80
K20-8 (2.2)
ZC (1.41)
-240
240
GK2471 (2.43)
+ 130
- 90
D3a 6004 (2.4)
-140
140
D3a 6397
(1.51)
200
BX 610 (2.2)
-160
K20-9 (2.0)
+160
BX663 (2.4)
110
BX528 (2.3)
160 50
GK 2113 (1.61)
+380
K20-7 (2.2)
-200
D3a (2.4)
ZC (2.2)
+200
BX482 (2.2)
SA (2.2)
-45
1 (8 kpc)
MD 41 (2.2)
Förster Schreiber et al. (2008)
The SINS Survey
Velocity of warm gas at every location. Red is redshifted, blue is blueshifted, green is zero. Some show something resembling ordered rotation (BX610) suggestive of a disk while others show a very odd velocity field (BX528) probably indicative of merger.

3. Qualitative Comparison to z~0 Spiral Galaxies
And their rotation curves look the same too.
Local rotation curves from
Sofue & Rubin 2001

4. Qualitative Comparison to z~0 Template Galaxies
Local Spiral Galaxy
Local ULIRG
Daigle et al. 2006
Colina et al. 2005
What are these things? What’s driving their rapid star formation (100 Msun/yr)? Compare to emission line observations of local systems, simulate at z=2.
Shapiro et al. 2008

5. Qualitative Comparison to z~0 Template Galaxies
Local Spiral Galaxy
Local ULIRG
Daigle et al. 2006
Colina et al. 2005
What are these things? What’s driving their rapid star formation (100 Msun/yr)? Compare to emission line observations of local systems, simulate at z=2.
Total: ~30 template galaxies, from local observations and simulations of high-z systems
(Simulations from Naab et al. 2007)
Shapiro et al. 2008

6. Quantifying Velocity Fields with Kinemetry
Kinemetry analysis of first and second velocity moment for highest quality SINS data …
Krajnović et al. 2006

7. Quantifying Velocity Fields with Kinemetry
Kinemetry analysis of first and second velocity moment for highest quality SINS data B1 … B3
Krajnović et al. 2006

8. Quantifying Velocity Fields with Kinemetry
Kinemetry analysis of first and second velocity moment for highest quality SINS data …
Krajnović et al. 2006

9. Classifying z~0 Template Galaxies
Shapiro et al. 2008

10. Classifying z~0 Template Galaxies
Kinemetry analysis of first and second velocity moment for highest quality SINS data
mergers
disk galaxies …
Krajnović et al. 2006
Shapiro et al. 2008

11. Classifying z~2 UV/optical-Bright Systems
Kinemetry analysis of first and second velocity moment for highest quality SINS data
mergers
disk galaxies
2 / 3 are disk-like
Shapiro et al. 2008

12. Classifying z~2 UV/optical-Bright Systems
Shapiro et al. 2008

13. Formation of Disks at z~2
BzK-15504
BzK-6004
BzK-ZC782941 Hα
Integrated
flux
FWHM 50 70 
(km/s)
Look at the formation of the system as a whole - star formation is a good probe of this. Halpha flux has large knots, regions of lots of star formation. Using the Halpha velocity dispersion at these points and assuming each knot is virialized, can estimate mass. Instability to condensations (and thus SF) depends on rotational speed, sound speed of the gas, and gas surface density. Is globally unstable to SF. Using Halpha intensity, can estimate SFR over the whole galaxy, is roughly 100 times that of the Milky Way and similar local galaxies.
500
160
170 60
MSF Region ~ 108 M
SFR ~ M/yr
Genzel et al. 2006

14. Formation of Disks at z~2
With SED modelling of broad band fluxes, find stellar mass and find SFR consistent with that measured from Halpha. Implies age of 500 Myrs is SFR roughly constant (not a very short burst). This matches stellar age.
M* ~ 8 x 1010 M
SFR ~ M/yr
Age ~ 500 Myr
Genzel et al. 2006

15. Formation of Disks at z~2
SED Modeling
tstars ~ 500 Myr
taccretion ~ tgas exhaustion ~ Myr
v / 2-4
(rapid) inflow scenario:
Dekel & Birnboim 2003,
Immeli et al. 2004,
D’Onghia et al. 2006
Stellar age = 500 Myr. V/sigma is ten times lower than in local disks - disks are dominated by large random motions. This may come either from gravitational infall potential energy or from feedback from star formation processes. In both cases, require rapid formation. Implies a rapid assembly where gas forms stars immediately when it reaches disk. Since no evidence of major merger, this inflow must be a more quiescent but still fast inflow from DM halo.
If age of stars was greater than gas exhaustion timescale, then star formation would have to happen in bursts.
Genzel et al. 2006

16. Future Evolution of z~2 Disks
Genzel et al. 2008
Immeli et al. 2004

17. The Evolution of z~2 UV/optical-bright Systems
Population consists mainly of large, rotating disks
Likely formed via smooth accretion, not major mergers
Evolve into z~0 bulge-dominated systems
Secular evolution may play an important role