The evolution of galaxy sizes since z=3 Ignacio Trujillo (MPIA) & the FIRES team (Trujillo et al. 2004, ApJ, 604, 521) (Trujillo et al. 2005, ApJ, submitted, astro-ph/ ) Luminosity-size relation Stellar Mass-size relation

People Involved P.I.: M. Franx (Leiden Observatory) 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) I. Labbé (Carnegie Observatories), H. Röttgering, A. van der Wel, P. van der Werf, L. van Starkenburg (Leiden Observatory) H.W. Rix (MPIA) H.W. Rix (MPIA) N.M. Förster Schreiber (MPE), G. Rudnick(NOAO) N.M. Förster Schreiber (MPE), G. Rudnick(NOAO) A. Moorwood (ESO), E. Daddi (NOAO) A. Moorwood (ESO), E. Daddi (NOAO) P. G. van Dokkum (Yale University) P. G. van Dokkum (Yale University) M. Barden, D. H. McIntosh, … (GEMS team) M. Barden, D. H. McIntosh, … (GEMS team)

Size evolution: Theoretical Expectations 1.Semianalytic, Hierarchical models (e.g. Mo et al. 1998): - Scaling relationships: M disk and R disk reflect M halo and l halo - Halos formed at high-z were much denser - Halos formed at high-z were much denser - Expected size scale evolution: R H -2/3 (z) at a fixed halo mass R H -2/3 (z) at a fixed halo mass R H -1 (z) at a fixed circular halo velocity 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(L B ) z

FIRES Sample Ultra-deep J, H & K images with the VLT of: Ultra-deep J, H & K images with the VLT of: Hubble Deep Field South IJK

FIRES Sample Ultradeep J, H & K images with the VLT of: Ultradeep J, H & K images with the VLT of: Hubble Deep Field South Cluster MS at z=0.83 (4xHDFs area) To avoid cluster contamination we only analyze z>1 galaxies… MS IJK

Luminosity-Size and Mass-Size Relations: The Sample K-band selected and z>1 objects down to: K-band selected and z>1 objects down to: K s,AB <23.5 (HDF-S) : 87 galaxies K s,AB <23.5 (HDF-S) : 87 galaxies K s,AB <23 (MS ): 175 galaxies K s,AB <23 (MS ): 175 galaxies Structural properties are obtained in its optical rest-frame band according to its redshift: Structural properties are obtained in its optical rest-frame band according to its redshift: 1<z<1.5 (J s band) 1.5<z<2.6 (H band) z>2.6 (K s 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 Sizes and concentrations are estimated fitting the galaxies with a Sérsic Model I(r)=I(0)e -b(r/re)^(1/n) 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 MS

Selection effects

Observed Luminosity-Size Relation disk-like spheroids-like SDSS relations: Shen et al. 2003

Observed Luminosity-Size Relation disk-like spheroids- like

Observed Mass-Size Relation disk-like spheroids-like SDSS relations: Shen et al. 2003

Observed Mass-Size Relation disk-likespheroids-like

GEMS (Barden et al. 2005;McIntosh et al. 2005) & FIRES disk-likespheroids-like

Size evolution: Conclusions z=2.5 galaxies with L V >3.4x10 10 L sun (V) were: at a given luminosity, 2.3 times smaller than local counterparts. z=2.5 galaxies with M * >3x10 10 M sun were: at a given stellar mass, 1.5 smaller. 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 Data Set Integration Time FWHM 1 s SB (AB mag/arcsec 2 ) Data Set Integration Time FWHM 1 s SB (AB mag/arcsec 2 ) WFPC2 U h 0.16” 29.5 WFPC2 U h 0.16” 29.5 WFPC2 B h 0.14” 30.3 WFPC2 B h 0.14” 30.3 WFPC2 V h 0.13” 30.6 WFPC2 V h 0.13” 30.6 WFPC2 I h 0.14” 30.0 WFPC2 I h 0.14” 30.0 ISAAC J s 33.6 h 0.45” 28.6 ISAAC J s 33.6 h 0.45” 28.6 ISAAC H 32.3 h 0.48” 28.1 ISAAC H 32.3 h 0.48” 28.1 ISAAC K s 35.6 h 0.46” 28.1 ISAAC K s 35.6 h 0.46” 28.1

FIRES MS Field Data Set Integration Time FWHM 1 s SB (AB mag/arcsec 2 ) Data Set Integration Time FWHM 1 s SB (AB mag/arcsec 2 ) FORS1 U 4.6 h 0.69” 29.0 FORS1 U 4.6 h 0.69” 29.0 FORS1 B 2.0 h 0.57” 29.6 FORS1 B 2.0 h 0.57” 29.6 FORS1 V 0.5 h 0.65” 28.8 FORS1 V 0.5 h 0.65” 28.8 WFPC2 V h 0.21” 30.0 WFPC2 V h 0.21” 30.0 WFPC2 I h 0.21” 29.2 WFPC2 I h 0.21” 29.2 ISAAC J s =26 h 0.48” ISAAC J s =26 h 0.48” ISAAC H =24.5h 0.46” ISAAC H =24.5h 0.46” ISAAC K s =26.6 h 0.52” ISAAC K s =26.6 h 0.52”

Galaxies with z<1: GEMS survey - P.I.: H.-W. Rix - GEMS area: 800 arcmin 2 - Two-color: F606W & F850LP - m AB (F606W)=28.3(5  ) - m AB (F850LP)=27.1(5  ) galaxies with photometric z from COMBO-17