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Clustering and dusty high-z galaxies

Clustering and dusty high-z galaxies. Emanuele Daddi ESO-Garching (  NOAO-Tucson). Properties of K-selected z=2 galaxies (K20/GOODS/other surveys)  dusty SF galaxies Efficient selection technique Clustering.

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Clustering and dusty high-z galaxies

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  1. Clustering and dusty high-z galaxies Emanuele Daddi ESO-Garching (NOAO-Tucson) • Properties of K-selected z=2 galaxies • (K20/GOODS/other surveys) •  dusty SF galaxies • Efficient selection technique • Clustering How, when did massive galaxies form ? Studying clustered high-z populations

  2. Near-IR bright z~2 galaxies K<20 at z~2  10^11 Msun stellar masses Too many massive galaxies at z>1.4 as compared to what LCDM models had predicted Cimatti et al. 2002, K20 survey

  3. SFR~50—500 Msun/yr, Lya emission often absent, red UV continua, strong absorption lines, Irregular/merging morphologies Daddi et al. 2004 ApJ 600 L127 Passive 1—2 Gyr galaxies, early-type morphologies Cimatti et al. 2004, Nature, 430, 184

  4. BzK selection technique BzK=(z-K)-(B-z) (AB mags) BzK>-0.2  SF at z>1.4 BzK<-0.2 & z-K>2.5  Old Daddi et al. 2004 ApJ in press astro-ph/0409041 94% of spec redshifts; K20 survey Technique calibrated with ~50 z>1.4 redshifts

  5. Reddening independent selection of SF galaxies Also because of K-selection Calzetti et al. 2000 extinction law Would miss <10Myr bursts Median E(B-V)~0.4 (from CSF models)

  6. UnGRs colors of K<20 z>1.4 sample BM/BX samples include K<20 sources (Shapley et al. 2004) but miss most reddened SF (~20--30% of total SFRD) and passive galaxies For K<20 sources Density is ~ 10^-3 h^3 Mpc^-3 comparable to local L>L* gals much smaller than LBGs

  7. X-ray stacking (Szokoly et al 2004; Gilli et al 2004) • Lx~ 8x10^41 cgs • HR < -0.54 (2-sigma) • star-forming galaxies • <SFR> ~ 200 Msun/yr Average 20cm radio emission also give 2-300 Msun/yr (Courtesy of K.Kellermann, J.Kelly; VLA data)

  8. SCUBA galaxies, or their remnants 6 objects: Photometric follow-up with SCUBA (with Rottgering, Cimatti, Kurk) One detection 4.5mJy (850mu) Positive flux from the others (about 1mJy, 2.5 sigma) (preliminary numbers)  Bridge to submm/mm populations ? More time allocated SCUBA/IRAM (but slow going…) Need Spitzer and/or future facilities to detect dust emission, even more for dusty K>20 sources

  9. BzK colors to identify counterparts ? See POSTER by Dannerbauer et al., this conference • But week correlation between • K and submm flux, why ? • week SFR/Mass correlation ? • redshift effects ? • Large/variable obscuration even • at K ?

  10. Forming progenitors of massiveearly-type galaxies detected ? • Large masses, near-IR bright (K<20@z~2) • Large SFRs (SFR>100 Msun/yr) • Metal enriched (Solar or more) • Density comparable to z=0 L>L* galaxies • Assembling by merging, perhaps some Are these strongly clustered ?

  11. Evidence for clustering Enhanced clustering of z~2—3 K-sel galaxies from FIRES, Daddi et al. 2003 Redshift pairings in the (SMALL) spectroscopic samples: e.g. Daddi et al. 2004; van Dokkum et al 2003 Monte Carlo simulations of clustered samples: r_o > 7 h^-1 Mpc (95% c.l.) Needs much larger sample to measure clustering

  12. ESO—Japan collaboration: ESO: Renzini, Cimatti, Mignoli, Pozzetti, Zamorani, Brusa, ED Subaru: Arimoto, Ikuta, Kong, Onodera, Ohta, etc 450 z>1.4 candidates BzK-sel 350 arcmin^2 field to K=20 (Kong et al. in preparation) ~ 300 spectra taken with VIMOS

  13. GMASS: ESO LP on UDF/K20/GOODS region PI: A. Cimatti 145 hours FORS2 ongoing Collaboration with GOODS Selection: IRAC 4.5mu<23.5 AB zphot>1.4, BzK 50 arcmin^2 region raw+reduced data will be publicly released

  14. GOODS/CDFS BzK selection to K=22 Vega (incomlete for reddest objs) VIMOS public observations: ~1000 BzKs (plus ~1000 UV-sel objects) PI: C. Cesarsky Catalogue by L.Moustakas, B.Mobasher, M.Dickinson, et al.

  15. COSMOS BzKs: 2 square degree, ~20000 BzKs Submitted ESO LP (>500n) PI: S.Lilly 10000 BzKs to be observed + 20000 UV-sel objects Catalogue Subaru+KPNO B.Mobasher, Y.Taniguchi, N.Scoville(PI) H.Aussel, P.Capak

  16. Angular clustering About 450 K<20 z>1.4 candidates; ESO/Japan obs of EIS Deep3a field

  17. N(z) K20 survey r_o ~ 8+-2 h^-1 Mpc (fixed delta=0.8) from Limber equation (main uncertainty N(z)) for BzK-SF BzK-Old seem to have higher angular clustering

  18. Preliminary COSMOS results A(1deg) ~0.008; S/N ~ 10 (fixed delta=0.8)  r_0 ~ 10+-2 h^-1 Mpc (main uncertainty N(z))

  19. Evolution: M>10^11 Msun (L>~L*) galaxies Tracks: evolution of DM halos from Mo & White 2002 • dusty z~2 K-bright galaxies consistent to evolve into EROs and local gEs clustering comparable to SCUBA objs (Blain et al. 2004), higher density LBGs have r_o~4 h^-1 Mpc (Adelberger et al 2005)

  20. GIF Models (Jenkins et al 1998; Kauffmann et al. 1999) • Correctly predict that at z>1.4 • objects with 10^11 Msun • stellar mass are either old/dead • or very active starbursts • AND classify the active starbursts • as early-type galaxies (bulge • dominated, red) • Agree with our conclusion that near-IR bright z>1.4 objects evolve into massive E/S0s • (but predict x10 too few objects)

  21. Conclusions • Population of massive dusty SF galaxies at z~2: bridge between submm/mm and LBGs, forming L>~L* early-type galaxies • BzK selection is very efficient for 1.4<z<2.5  reddening independent selection of SF galaxies • Clustering is an important measure for dusty high-z galaxies (link to evolution, DM halos properties, etc). Requires statistics (N_objs), wide/many fields, redshifts for high significance measurements

  22. Passive BzKs in UDF Daddi et al 2005 (in preparation) ACS+HST spectra from GRAPES project (PI Malhotra) ACSNICMOS imaging

  23. Average UV spectra: de Mello et al. 2004 ApJ 608 L29 NGC 6090: Merger, dusty, LIRG, metal rich

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