Clustering and dusty highz galaxies

1
Clustering and dusty high-z galaxies

• Emanuele Daddi
• ESO-Garching
• (?NOAO-Tucson)

• Properties of K-selected z2 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 z2 galaxies
Klt20 at z2 ? 1011 Msun stellar masses
Too many massive galaxies at zgt1.4 as compared
to what LCDM models had predicted
Cimatti et al. 2002, K20 survey
3
SFR50500 Msun/yr, Lya emission often
absent, red UV continua, strong absorption lines,
Irregular/merging morphologies Daddi et al. 2004
ApJ 600 L127

Passive 12 Gyr galaxies, early-type
morphologies Cimatti et al. 2004, Nature, 430,
184
4
BzK selection technique
BzK(z-K)-(B-z) (AB mags) BzKgt-0.2 ? SF at
zgt1.4 BzKlt-0.2 z-Kgt2.5 ? Old
Daddi et al. 2004 ApJ in press astro-ph/0409041
94 of spec redshifts K20 survey Technique
calibrated with 50 zgt1.4 redshifts
5
Reddening independent selection of SF galaxies
Also because of K-selection Calzetti et al. 2000
extinction law Would miss lt10Myr bursts
Median E(B-V)0.4 (from CSF models)
6
UnGRs colors of Klt20 zgt1.4 sample
BM/BX samples include Klt20 sources (Shapley et
al. 2004) but miss most reddened SF (20--30 of
total SFRD) and passive galaxies
For Klt20 sources Density is 10-3 h3
Mpc-3 comparable to local LgtL gals much smaller
than LBGs
7
X-ray stacking
(Szokoly et al 2004 Gilli et al 2004)

• Lx 8x1041 cgs
• HR lt -0.54 (2-sigma)
• star-forming galaxies
• ltSFRgt 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 Kgt20 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 (Klt20_at_z2)
• Large SFRs (SFRgt100 Msun/yr)
• Metal enriched (Solar or more)
• Density comparable to z0 LgtL galaxies
• Assembling by merging, perhaps some
• Are these strongly clustered ?

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Evidence for clustering
Enhanced clustering of z23 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 gt 7 h-1
Mpc (95 c.l.) Needs much larger sample to
measure clustering
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ESOJapan collaboration
ESO Renzini, Cimatti, Mignoli, Pozzetti,
Zamorani, Brusa, ED
Subaru Arimoto, Ikuta, Kong, Onodera, Ohta, etc
450 zgt1.4 candidates BzK-sel 350 arcmin2
field to K20 (Kong et al. in preparation)
300 spectra taken with VIMOS
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GMASS ESO LP on UDF/K20/GOODS region
PI A. Cimatti 145 hours FORS2 ongoing Collaborat
ion with GOODS Selection IRAC 4.5mult23.5
AB zphotgt1.4, BzK 50 arcmin2 region
rawreduced data will be publicly released
14
GOODS/CDFS
BzK selection to K22 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 (gt500n) PI S.Lilly 10000 BzKs
to be observed 20000 UV-sel objects Catalogue
SubaruKPNO B.Mobasher, Y.Taniguchi, N.Scoville(PI
) H.Aussel, P.Capak
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Angular clustering
About 450 Klt20 zgt1.4 candidates ESO/Japan obs
of EIS Deep3a field
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N(z) K20 survey
r_o 8-2 h-1 Mpc (fixed delta0.8) from
Limber equation (main uncertainty N(z)) for
BzK-SF BzK-Old seem to have higher angular
clustering
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Preliminary COSMOS results
A(1deg) 0.008 S/N 10 (fixed delta0.8) ?
r_0 10-2 h-1 Mpc (main uncertainty N(z))
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Evolution Mgt1011 Msun (LgtL) galaxies
Tracks evolution of DM halos from Mo White 2002

• dusty z2 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_o4 h-1 Mpc (Adelberger et al
  2005)

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GIF Models (Jenkins et al 1998 Kauffmann et al.
1999)

• Correctly predict that at zgt1.4
• objects with 1011 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 zgt1.4 objects
• evolve into massive E/S0s
• (but predict x10 too few objects)

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Conclusions

• Population of massive dusty SF galaxies at z2
  bridge between
• submm/mm and LBGs, forming LgtL early-type
  galaxies
• BzK selection is very efficient for 1.4ltzlt2.5 ?
  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)
ACSHST 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