Transcript Diapositiva 1 - University of Groningen

The evolution of galaxy sizes
since z=3
Luminosity-size relation
Stellar Mass-size relation
Ignacio Trujillo (MPIA) & the FIRES team
(Trujillo et al. 2004, ApJ, 604, 521)
(Trujillo et al. 2005, ApJ, submitted, astro-ph/0504225)
People Involved
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P.I.: M. Franx (Leiden Observatory)
I. Labbé (Carnegie Observatories), H. Röttgering,
A. van der Wel, P. van der Werf, L. van Starkenburg
(Leiden Observatory)
H.W. Rix (MPIA)
N.M. Förster Schreiber (MPE), G. Rudnick(NOAO)
A. Moorwood (ESO), E. Daddi (NOAO)
P. G. van Dokkum (Yale University)
M. Barden, D. H. McIntosh, … (GEMS team)
Size evolution: Theoretical
Expectations
1. Semianalytic, Hierarchical models (e.g. Mo et al.
1998):
- Scaling relationships: Mdisk and Rdisk reflect
Mhalo and lhalo
- Halos formed at high-z were much denser
- Expected size scale evolution:
R  H-2/3(z) at a fixed halo mass
R H-1 (z) at a fixed circular halo velocity
Size evolution: Theoretical
Expectations
2. Infall models (e.g. Cayón et al. 1996):
- Use the observed local disk properties (gas and
stellar profiles, metallicity, etc…) as a reference
- Star Formation Rate depends on radius and time
following a Schmidt-type law
- Metal-free gas falls in
Bouwens & Silk (2002) propose: R(LB) 1-0.27z
FIRES Sample
Ultra-deep J, H & K images with the VLT of:
Hubble Deep Field South
IJK
MS1054-03
FIRES Sample
Ultradeep J, H & K images with the VLT of:
Hubble Deep Field South
Cluster MS1054-03 at z=0.83 (4xHDFs area)
To avoid cluster contamination we only analyze z>1
galaxies…
IJK
Luminosity-Size and Mass-Size
Relations: The Sample
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K-band selected and z>1 objects down to:
Ks,AB<23.5 (HDF-S) : 87 galaxies
Ks,AB<23 (MS1054-03): 175 galaxies
Structural properties are obtained in its optical
rest-frame band according to its redshift:
1<z<1.5 (Js band)
1.5<z<2.6 (H band)
z>2.6 (Ks band)
zphot and rest-frame Lum. Estimations
Rudnick et al. (2003;2005)
Luminosity-Size and Mass-Size
Relations: The Masses
Stellar masses are determined from the relation between
rest-frame (B-V) color and M/L (Bell & de Jong 2001)
Size estimations at high-z:
Technique
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Sizes and concentrations are estimated fitting
the galaxies with a Sérsic Model
I(r)=I(0)e-b(r/re)^(1/n)
 disk-like
 spheroid-like
Selection effects
MS1054-03
Selection effects
Observed Luminosity-Size Relation
SDSS relations: Shen et al. 2003
disk-like
spheroids-like
Observed Luminosity-Size Relation
disk-like
spheroidslike
Observed Mass-Size Relation
SDSS relations: Shen et al. 2003
disk-like
spheroids-like
Observed Mass-Size Relation
disk-like
spheroids-like
GEMS(Barden et al. 2005;McIntosh et al. 2005)& FIRES
disk-like
spheroids-like
Size evolution: Conclusions
z=2.5 galaxies with LV>3.4x1010 Lsun(V) were:
at a given luminosity, 2.3 times smaller than local
counterparts.
z=2.5 galaxies with M*>3x1010 Msun were:
at a given stellar mass, 1.5 smaller.
We can reconcile these two results because high-z
galaxies have young stellar populations.
Inside-Out Galaxy Formation
FIRES HDFS
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Data Set
Integration Time
FWHM
1s SB (AB mag/arcsec2)
WFPC2
WFPC2
WFPC2
WFPC2
U300
B450
V606
I814
36.8 h
28.3 h
27.0 h
31.2 h
0.16”
0.14”
0.13”
0.14”
29.5
30.3
30.6
30.0
ISAAC
ISAAC
ISAAC
Js
H
Ks
33.6 h
32.3 h
35.6 h
0.45”
0.48”
0.46”
28.6
28.1
28.1
FIRES MS1054-03 Field
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Data Set
Integration Time
FWHM
1s SB (AB mag/arcsec2)
FORS1 U
FORS1 B
FORS1 V
4.6 h
2.0 h
0.5 h
0.69”
0.57”
0.65”
29.0
29.6
28.8
WFPC2 V606
WFPC2 I814
1.8 h
1.8 h
0.21”
0.21”
30.0
29.2
ISAAC
ISAAC
ISAAC
Js 7+7+6+6=26 h
0.48”
H 6.5+6+6+6=24.5h 0.46”
Ks 8+6.5+6+6=26.6 h 0.52”
27.8-28.0
27.3-27.6
27.2-27.6
Galaxies with z<1: GEMS survey
- P.I.: H.-W. Rix
- GEMS area: 800 arcmin2
- Two-color: F606W &
F850LP
- mAB(F606W)=28.3(5s)
- mAB(F850LP)=27.1(5s)
- 10000 galaxies with
photometric z from
COMBO-17