MUSYC E-HDFS UBR composite

Formation and Clustering of High-redshift Galaxies

3. Galaxy Clustering

Eric GawiserRutgers University

Protogalaxies at z=3: TLAs

• LBG=Lyman Break Galaxy selected via Lyman break, blue continuum (starburst)

• LAE=Lyman Alpha Emitter selected via strong emission line (early stage of star formation)

• DRG=Distant Red Galaxy selected via Balmer break in observed NIR

• SMG=Sub-Millimeter Galaxy selected in sub-mm, use radio to get position

• DLA=Damped Lyman Absorption system selected in absorption, N(HI)>1020 cm-2

Images from HST-ACS: irregular morphology at z=3

AGN z=3.60 R=22.4

LBG z=3.37 R=24.3

LBG z=3.24 R=23.8

LAE z=3.10 R=26.1

ECDFS RJK

NIR selects rest-frame Balmer/4000Å break at 2<z<4

Reddy et al 2005Reddy et al 2005

Distant Red Galaxies (DRG)

van Dokkum et al 2005, in prep. MUSYCMUSYCvan Dokkum et al 2006van Dokkum et al 2006

Sub-Millimeter Galaxy contribution to

Star Formation Rate Density

Chapman et al 2005Chapman et al 2005

LBGs and LAEs in MUSYC-ECDFSLBGs and LAEs in MUSYC-ECDFS

1240 LBGs 162 LAEs

Projection of 12(r )=(r/r0)- into

w12() = dz1 dz2 p1(z1)p2(z2) 12(r(z1,z2, )) Need redshifts to determine selection functions pi(z) for inversion of w12() to determine 12(r)

Spatial and angular cross-correlation functions:Spatial and angular cross-correlation functions:

dP(r) = dP(r) = 1122[1 + [1 + 12(r)] (r)] dV1 dV dV22

dP(dP() = ) = 1122[1 + w[1 + w1212(()] )] d1 d2

For autocorrelation and acceptable geometry, Limber approximation

w() = 1- r0 (1/2, (-1)/2) p2(z) (1+z)1- DA(z)1-

H(z)/c dz

LBG and LAE redshift distributions

2.8<z<3.7 expected for UVR Dark curve shows selection function: narrow-band filter response convolved with EW distribution

LAELBG

Measuring angular auto-Measuring angular auto-correlationcorrelation

((): Excess probability of ): Excess probability of finding pairs separated by finding pairs separated by angular distance angular distance over uniform over uniform distributiondistribution

Landy-Szalay estimator uses Landy-Szalay estimator uses counts of pairs separated by counts of pairs separated by – DD: between data pairsDD: between data pairs– DR: data-random pairsDR: data-random pairs– RR: random-random pairsRR: random-random pairs

The random pairs “subtract” the excess probability that is The random pairs “subtract” the excess probability that is due to the geometry of the surveydue to the geometry of the survey Usually assumed that Usually assumed that (() = A) = A--

LBGs and LAEs in MUSYC-ECDFSLBGs and LAEs in MUSYC-ECDFS

1240 LBGs 162 LAEs

LBGs in MUSYC-ECDFSLBGs in MUSYC-ECDFS

1240 LBGs Clustering analysis byHarold Francke

LAEs in MUSYC-ECDFSLAEs in MUSYC-ECDFS

162 LAEs Clustering analysis by H. Francke

Clustering Determination

• LBG, LAE, and DRG samples are large enough to use r0 to determine bias

LBG-LBG( r ) = (r/r0)- =b2LBG DM( r )

• SMG, DLA samples are small, so study cross-correlation with numerous LBGs to determine bias

DLA-LBG( r ) =(r/r0)- = bDLAbLBG DM( r )

• bLBG etc. determine typical dark matter halo masses of each family of protogalaxies

Method for auto-correlation from Mo & White 1996, MNRAS 282, 347 First applied to cross-correlation by Gawiser et al 2001, ApJ 562, 628

Bias minimum DM halo mass

number abundance of host halos

MUSYCMUSYCQuadri et al 2007Quadri et al 2007

Clustering vs. halo abundance

What are the low-redshift descendants of z=3 galaxies?

Gawiser et al 2007, in prep

LAE

5 Unsolved Problems in Galaxy Formation

1. What does a protogalaxy look like?

Did galaxy, stars, supermassive black holes all form simultaneously?

5 Unsolved Problems in Galaxy Formation

1. What does a protogalaxy look like?

2. When/how did each component form?

Thin disk: 10 Gyr - formed at z~2 but simulations have trouble making. Angular momentum coupling between DM & baryons affects bar/disk formation and bulge cuspiness.

Globular clusters: formed by Pop III stars in 106 M halos?

5 Unsolved Problems in Galaxy Formation

1. What does a protogalaxy look like?

2. When/how did each component form?

3. When/how did galaxy sequences evolve? Hubble sequence not yet present at z>2

Red/blue sequences (bimodality of properties)

require “gastrophysics”

5 Unsolved Problems in Galaxy Formation

1. What does a protogalaxy look like?2. When/how did each component form?3. When/how did galaxy sequences evolve?4. What role did feedback play? Feedback from AGN & supernovae regulates

BH/bulge formation, cuspiness of DM halo, baryonic mass loss, IGM enrichment, minimum galaxy mass

5 Unsolved Problems in Galaxy Formation

1. What does a protogalaxy look like?2. When/how did each component form?3. When/how did galaxy sequences evolve?4. What role did feedback play?5. When/how was the universe reionized? Top-heavy IMF predicted at high-z due to low

metallicity but exact mass range/epoch unknown and nature of “surviving” galaxies is sensitive

Coming Attractions

• Unification of galaxy formation and evolution Needle-in-haystack techniques evolved gals at z>2 Multiwavelength high-z analogs at low-z Evolutionary sequence (e.g. DLALAELBGSMGDRG) as part of “grand unified” model of galaxies & AGN Spitzer is key

Coming Attractions

• Unification of galaxy formation and evolution

• ISM in emission at high-redshift CO, [CII] 158 micron with ALMA Compare gas mass with stellar mass Compare tips of high-redshift gas and stellar

luminosity functions

Coming Attractions

• Unification of galaxy formation and evolution

• ISM in emission at high-redshift

• High-redshift galaxies constrain dark energy? Baryon oscillations as standard rod - need z>1 point to

constrain equation-of-state (w) of dark energy A million redshifts needed? WFMOS! Blake & Glazebrook 2003, Linder 2003, Seo & Eisenstein 2003

Coming Attractions

• Unification of galaxy formation and evolution

• ISM in emission at high-redshift

• High-redshift galaxies constrain dark energy?

• More jargon Sub-classes (sub-DLAs, bDLAs) may force FLAs! N2 cross-correlation functions

MUSYC Public Data Release

June 1, 2007 at http://www.astro.yale.edu/MUSYC

UBVRIzK imaging of 1.2 square degrees to U,B,V,R = 26, K=22 (AB)

JHK imaging of 0.1 square degrees to K=23 (AB)

Deep Spitzer+IRAC imaging (all 4 bands) of ECDF-S