1. Large-Scale Structure at z=1: Results from the DEEP2 Survey Alison Coil Steward Observatory University of Arizona March 2006

2. Talk Overview DEEP2 Redshift Survey overview Luminosity-dependence of Clustering at z=1 Galaxy Properties vs. Environment Evolution of Blue Fraction in Groups QSO-galaxy clustering

3. The DEEP2 Collaboration U.C. Berkeley M. Davis (PI) M. Cooper B. Gerke R. Yan C. Conroy Steward Obs. A. Coil U.C. Santa Cruz S. Faber (Co-PI) D. Koo P. Guhathakurta D. Phillips K. Noeske A. Metevier L. Lin N. Konidaris G. Graves LBNL J. Newman Maryland B. Weiner Virginia R. Schiavon NOAO J. Lotz The DEEP2 Galaxy Redshift Survey, which uses the DEIMOS spectrograph on the Keck II telescope, is studying both galaxy properties and large-scale structure at z=1. C. Willmer

4. Comparison with Other Surveys z~0 z~1 DEEP2 SDSS 2dF CFA+ SSRS LCRS PSCZ DEEP2 was designed to have comparable size and density to previous generation local redshift surveys and is >50 times larger than previous intermediate surveys at z~0.3-1. DEEP2 has a different geometry than local surveys: 20x~80x1000 h -3 Mpc 3 per field few x smaller than 2dF >4x larger than VVDS ~2.5x COMBO-17

5. Vital Statistics of DEEP2 3 sq. degrees of sky 4 fields (0.5 o x <2 o ) - lower cosmic variance errors primary z~0.7-1.4 (pre-selected using BRI photometry) >40,000 redshifts comoving volume: ~5·10 6 h -3 Mpc 3 400 slitmasks over 80 Keck nights One-hour exposures R AB =24.1 limiting magnitude 1200 l/mm: ~6500-9200 Å 1.0” slit: FWHM  68 km/s - high-resolution

6. AEGIS: the All-wavelength Extended Groth Strip International Survey Spitzer MIPS, IRAC DEEP2 spectra and K s imaging HST/ACS V,I (Cycle 13) Background: 2 x 2 deg from POSS DEEP2/CFHT B,R,I GALEX NUV+FUV Chandra & XMM: Past coverage Awarded (1.4Ms) VLA - 6cm (0.5 mJy) + 21cm (0.1 mJy) SCUBA

7. AEGIS ApJ Letters in prep: Conselice: Properties of Massive and Red Galaxies Fang: Chandra observations of DEEP2 groups Georgakakis: Environments of Chandra sources Gerke: A binary AGN at z=0.71 Huang: Mid-Infrared Spectroscopy of a very massive LBG at z=2.98 Ivison: Deep radio imaging of EGS Kirby: SEDs of faint galaxies Le Floc'h: Hidden star formation associated with a bright X-ray source Lin: SFR in close pairs Metevier: Tully-Fisher relation for z>=0.9 galaxies in EGS Moustakas: Strong gravitational lensing in the EGS Nandra: Host galaxy colors and masses of X-ray selected AGN Pierce: AGN host morphologies Weiner: Extinction and Star Formation Rate Calibrations from Optical Emission Lines

8. Evolution of Galaxy Morphology in EGS Poster by J. Lotz on changes in morphological distribution of galaxies from z=1.2 to z=0.3 using ~2000 DEEP2 galaxies: 1.buildup of E/S0/Sa since z~1 2.red sequence is mostly disk galaxies at z~1 and E/S0/Sa by z~0.3 3.merger fraction is less than 10% and constant with z 4.fraction of irregular galaxies decreases toward low z 5.most 24  m sources are Sc/d/Irr

9. Redshift Distribution of Data: z~0.7-1.4 Status: -three-year survey -currently ~90% complete -finishing EGS this spring Target galaxies to be at z>0.7 with B-R, R-I colors. The cuts are very successful! Only miss 3% of high-z objects (blue). Don’t apply color cut in the EGS. Redshifts are precise (30 km/s) and have high confidence: OII doublet and Ca H+K abs. features

10. DEEP2 sees the same color bi-modality as SDSS, COMBO-17, etc. to z>1 red blue brightfaint two distinct spectral types as well

11. Evolution of the Luminosity Function Willmer et al, 2005 + Faber et al. 2005, ApJ M* evolves by ~1.3 mags/z - brighter in past for both red and blue galaxies! Number density is ~constant for blue and lower at z=1 for red galaxies. Build-up of galaxies on the red sequence. The red population is not just evolving passively!

12. Redshift Maps in 4 Fields: z=0.7-1.3 Cone diagram of 1/12 of the full DEEP2 sample

13. Luminosity-dependence of clustering at z=1 in DEEP2 data From a sample of 25,000 redshifts over 3 deg 2 in 4 fields - create volume-limited subsamples as a function of luminosity. Brighter samples are more clustered and have steeper slopes on small scales -- preferentially found in groups at z=1 -- sub-structure. Coil et al. 2006, ApJ 100 kpc/h20 Mpc/h Galaxy separation (Mpc/h) w p (r p ) - clustering amplitude

14. Deviations from a power-law at z=1 Similar deviations from a power-law that are seen at z=0.1. Generally interpreted as one-halo and two-halo terms. Coil et al. 2006, ApJ SDSS z=0.1DEEP2 z=1

15. Measure one-halo and two-halo terms Coil et al., ApJ 2005 Can measure the one-halo and two-halo terms directly with a group catalog! Compare with mock catalogs that use an HOD model + DM NFW profile and find a discrepancy on small scales - ? DataMock

16. Luminosity/scale-dependence of bias From the observed bias can infer the dark matter halo masses that host these galaxies: M > 9 10 11 -3 10 12 M  /h Have now measured the scale-dependence and luminosity-dependence of galaxy bias at z=1! Rise in bias on small scales reflects physics of galaxy formation and radial profile of galaxies in halos. DEEP2 sample - large-scales: b =1.26 (0.04) - 1.54 (0.05)

17. Theoretical Modelling of  (r) Diamonds - DEEP2 results Solid line - theoretical model Dotted line - dark matter Conroy, Wechsler and Kravtsov 2006, ApJ predict the luminosity- dependent  (r) using dark matter simulations - identify halos and subhalos, assign L using the observed LF and the dist. of (sub)halo masses by matching number densities: get a simple relation b/w L-V max of halo -reproduce DEEP2 results quite well! (incl. rise on small scales) Implies that luminosity- dependence of clustering is driven by mass of (sub)halos

18. Galaxy Properties and Environment We can measure the local density - i.e., the “environment” of any given object - using the distance to the 3rd nearest neighbor DEEP2 galaxy. Cooper et al. 2006, ApJ: astro-ph/0603177 blue color red linear overdensity blue color red log overdensity DEEP2 SDSS (Blanton et al. 2004)

19. Environment over the CMD Basic trends from z~0 studies persist at z~1: e.g., the reddest and brightest galaxies are preferentially found in dense environments. brighter redder SDSS, z~0.1DEEP2, 0.75<z<1.05 Cooper et al. 2006, ApJ: astro-ph/0603177

20. Environment vs. Luminosity However, unlike locally, red and blue galaxies have very similar trends of environment vs. luminosity at z~1. Blue galaxiesRed galaxies brighter denser brighter Cooper et al. 2006, ApJ: astro-ph/0603177

21. In other words… There exists a population of bright, blue galaxies in dense regions that is present at z~1 but not today. Presumably, their star-formation has quenched and are now on the red sequence. denserbrighter

22. Baby pictures of today’s RS galaxies? ACS data in the EGS - bright blue galaxies at z~1

23. Finding groups in DEEP2 We find groups using the locations of galaxies in redshift space - no selection based on color, magnitude, etc. - just overdensity in the galaxy distribution. position Uses of groups include: 1.LSS/cosmology: N( ,z) constrains w 2.Galaxy formation and evolution: e.g., the Butcher-Oemler effect

24. First DEEP2 Group Catalog Gerke et al. 2005, ApJ We currently have group catalogs for all 4 fields

25. Color/environment trend is driven by group (not massive cluster) galaxies log overdensity blue red After group and cluster galaxies are removed Mean & median trends Cooper et al. 2006, ApJ: astro-ph/0603177

26. Do these trends evolve over time? Sample definition is critical for a clean test of the Butcher-Oemler effect. Volume-limited samples, to diff. limiting mag, w/ and w/o passive evolution. Tested extensively in mock catalogs w/ and w/o evolution in them. brighter Gerke et al. 2006, in prep

27. Evolution of blue fraction in groups The blue fraction is lower in groups than the field, but evolves more quickly, and appears to be converging w/ field at z~1.2. Suggests that galaxies in groups start quenching at z~1.5 or so. increasing z Gerke et al. 2006, in prep

28. SDSS QSOs in DEEP2 fields Coil et al., ApJ submitted 36 SDSS + 16 DEEP2 spectroscopic QSOs in the DEEP2 fields between z=0.7-1.4:

29. Clustering of Galaxies around QSOs Clustering of DEEP2 galaxies around SDSS QSOs at z=0.7-1.4. Errors include Poisson errors + cosmic variance. Why measure the cross- correlation? Divide by the clustering of DEEP2 galaxies around DEEP2 galaxies to get the bias of QSO hosts… Coil et al., ApJ submitted

30. Relative bias of QSOs to DEEP2 galaxies The relative bias is ~1 +/-0.2 Galaxies that host QSOs at z=1 have the same clustering properties (same halo mass) as typical DEEP2 galaxies. Don’t have same clustering as red/early-type galaxies (2  result) - -- see the same result using local environment/overdensity Places constraints on theoretical and semi-analytic models of quasars (Hopkins, Croton, etc.) Coil et al., ApJ submitted

31. Other DEEP2 Papers Clustering of Groups and Group Galaxies (Coil et al., ApJ) Void Probability Function (Conroy et al., ApJ) Merger rate (Lin et al., ApJ) Satellite Galaxy Kinematics (Conroy et al., ApJ) Environments in Deep Redshift Surveys (Cooper et al., ApJ) Metallicities of DEEP2 Galaxies (Shapley et al., ApJ) Evolution of Galaxy Morphologies (Lotz et al., submitted ApJ) Ages/Zs of early-type galaxies (Schiavon et al., submitted ApJ) K+A/post-starburst galaxies (Yan et al., in prep) Evolution of fine structure constant (Newman et al., in prep) Data Release 1 (DR1): http://deep.berkeley.edu/DR1 - 1st season’s data - 7,500 redshifts + spectra - ~20% of full dataset