Massive clusters of galaxies have been found as early as 3.9 Billion years
(z=1.62) after the Big Bang containing stars that formed at even earlier
epochs. Cosmological simulations using the current cold dark matter paradigm
predict these systems should descend from "proto-clusters" - early
over-densities of massive galaxies that merge hierarchically to form a cluster.
These proto-cluster regions themselves are built-up hierarchically and so are
expected to contain extremely massive galaxies which can be observed as
luminous quasars and starbursts. However, observational evidence for this
scenario is sparse due to the fact that high-redshift proto-clusters are rare
and difficult to observe. Here we report a proto-cluster region 1 billion years
(z=5.3) after the Big Bang. This cluster of massive galaxies extends over >13
Mega-parsecs, contains a luminous quasar as well as a system rich in molecular
gas. These massive galaxies place a lower limit of >4x10^11 solar masses of
dark and luminous matter in this region consistent with that expected from
cosmological simulations for the earliest galaxy clusters.Comment: Accepted to Nature, 16 Pages, 6 figure

Alexander Karim

B Robertson

Bahram Mobasher

Brant Robertson

C Maraston

C Papovich

Chris Carilli

D Calzetti

D Riechers

Dominik Riechers

DP Stark

E Schinnerer

Eva Schinnerer

F Walter

Francesca Civano

GK Miley

Grant W. Wilson

H Hildebrandt

J Kennicutt

JD Younger

Johannes G. Staguhn

KS Scott

L Tacconi

Lin Yan

LJ Tacconi

M Brusa

M Elvis

M Pettini

Mara Salvato

Martin Elvis

Min Yun

Nick Z. Scoville

NZ Scoville

P Capak

Peter L. Capak

Pierre Cox

R Overzier

R Wang

RJ Bouwens

Roberto Neri

S Mei

V Springel

Y Li

English

arXiv

Massive clusters of galaxies have been found that date from as early as 3.9 billion years (3.9Gyr z = 1.62) after the Big Bang, containing stars that formed at even earlier epochs. Cosmological simulations using the current cold dark matter model predict that these systems should descend from `protoclusters'-early overdensities of massive galaxies that merge hierarchically to form a cluster. These protocluster regions themselves are built up hierarchically and so are expected to contain extremely massive galaxies that can be observed as luminous quasars and starbursts. Observational evidence for this picture, however, is sparse because high-redshift protoclusters are rare and difficult to observe. Here we report a protocluster region that dates from 1Gyr (z = 5.3) after the Big Bang. This cluster of massive galaxies extends over more than 13 megaparsecs and contains a luminous quasar as well as a system rich in molecular gas. These massive galaxies place a lower limit of more than 4Ãâ1011 solar masses of dark and luminous matter in this region, consistent with that expected from cosmological simulations for the earliest galaxy clusters

Capak, Peter L.

Riechers, Dominik

Scoville, Nick Z.

Carilli, Chris

Cox, Pierre

Neri, Roberto

Robertson, Brant

Salvato, Mara

Schinnerer, Eva

Yan, Lin

Wilson, Grant W.

Yun, Min

Civano, Francesca

Elvis, Martin

Karim, Alexander

Mobasher, Bahram

Staguhn, Johannes G.

Max Planck Society eDoc Server

A massive protocluster of galaxies at a redshift of z~5.3

Massive clusters of galaxies have been found that date from as early as 3.9 billion years1 (3.9 Gyr; z = 1.62) after the Big Bang, containing stars that formed at even earlier epochs2, 3. Cosmological simulations using the current cold dark matter model predict that these systems should descend from ‘protoclusters’—early overdensities of massive galaxies that merge hierarchically to form a cluster4, 5. These protocluster regions themselves are built up hierarchically and so are expected to contain extremely massive galaxies that can be observed as luminous quasars and starbursts4, 5, 6. Observational evidence for this picture, however, is sparse because high-redshift protoclusters are rare and difficult to observe6, 7. Here we report a protocluster region that dates from 1 Gyr (z = 5.3) after the Big Bang. This cluster of massive galaxies extends over more than 13 megaparsecs and contains a luminous quasar as well as a system rich in molecular gas8. These massive galaxies place a lower limit of more than 4 × 1011 solar masses of dark and luminous matter in this region, consistent with that expected from cosmological simulations for the earliest galaxy clusters4, 5, 7

Capak, PL

Riechers, D

Scoville, NZ

Carilli, C

Cox, P

Neri, R

Robertson, B

Savato, M

Schinnerer, E

Yan, L

Wilson, GW

Civano, F

Elvis, M

Karim, A

Mobasher, B

Staguhn, JG

ScholarWorks@UMass Amherst

A massive protocluster of galaxies at a redshift of z ≈ 5.3

Massive clusters of galaxies have been found that date from as early as 3.9 billion years (3.9 Gyr; z = 1.62) after the Big Bang, containing stars that formed at even earlier epochs. Cosmological simulations using the current cold dark matter model predict that these systems should descend from ‘protoclusters’—early overdensities of massive galaxies that merge hierarchically to form a cluster. These protocluster regions themselves are built up hierarchically and so are expected to contain extremely massive galaxies that can be observed as luminous quasars and starbursts. Observational evidence for this picture, however, is sparse because high-redshift protoclusters are rare and difficult to observe. Here we report a protocluster region that dates from 1 Gyr (z = 5.3) after the Big Bang. This cluster of massive galaxies extends over more than 13 megaparsecs and contains a luminous quasar as well as a system rich in molecular gas. These massive galaxies place a lower limit of more than 4 × 10^(11) solar masses of dark and luminous matter in this region, consistent with that expected from cosmological simulations for the earliest galaxy clusters

Caltech Authors - Main

1. IRAC Photometry 
Spitzer IRAC fluxes were measured from a combination of programs 20070 
(COSMOS) , 40801, 50310 and 61043 (SEDS) in the COSMOS field.  The data for 
program 61043 were obtained during the Spitzer warm mission and only the data 
obtained in January 2010 were used for this paper.  The average exposure time at the 
position of the proto-cluster is 6.3 hours per pixel. 
The data reduction procedure closely follows that used for the COSMOS data 
(program 20070)29. We began our reduction using the corrected basic calibrated data 
(cBCD) provided by the Spitzer Science Center.  The cBCDs were background matched 
using the contributed afrl_bcd_overlap IDL procedure, and then combined into a mosaic 
using the MOPEX software package.  Cosmic rays, asteroids, and other transient 
artefacts were removed using the MOPEX temporal and box outlier modules.  The 
images were combined using a drizzle interpolation with a PIXFRAC of 0.65 and an 
exposure time weighted co-addition. The resulting image has a 1 sigma, background 
limited, point source sensitivity of 38 nJy and 44 nJy in 3.6μm and 4.5μm respectively 
for the region around the proto-cluster.  
Fluxes were measured by fitting an empirically measured point spread function 
(PSF) at the source position.  Compact sources within 5 arc-minutes of the proto-cluster 
were used to construct the PSF model.  For un-confused sources the PSF fit fluxes 
agreed well with 3.8” diameter aperture photometry measurements corrected to total 
flux via a statistical aperture correction.  The new IRAC fluxes for the sources are given 
in Supplementary Table 1. 
2. 2mm Observations of COSMOS AzTEC-3 
The Goddard-IRAM Superconducting 2-Millimeter Observer  (GISMO) is a 
bolometer camera optimized for 2-millimeter observations at the IRAM 30m telescope. 
GISMO uses a closed packed 128 element transition edge sensor (TES) detector array 
with an instantaneous field of view of 2’x4’.  The observations of AzTEC-3 were 
obtained on April 12, 2010 with 100 minutes of integration. Flux calibrations were 
obtained to 18% accuracy with observations of Mars and pointing was verified by 
frequent observations of the nearby quasar J0948+003.  The data were reduced and 
calibrated using the CRUSH-2 data reduction package. 
We detect a source with 3.1σ significance based on the 18” beam-smoothed flux 
maps and the noise maps within the expected positional error of AzTEC-3.  Including 
the statistical, calibration, and positional errors the detection of AzTEC-3 has a 99% 
statistical probability.   We estimate the 2mm flux to be 3.7±1.4 mJy including 
uncertainty from the flux calibration.  We note the 2mm flux is not corrected for 
possible flux boosting14 since this correction factor requires knowledge of the 2mm 
number counts and these are not well measured.  
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3. Selecting Cluster Members   
One of the great strengths of the COSMOS data are the extremely accurate 
(dz/(1+z)<0.01) photometric redshfits at z<1.530.  However, the techniques used to 
construct the photometric redshifts suffer from catastrophic failures when applied to 
high redshift and extreme sources such as those in our proto-cluster. Supplementary 
Figure 1 shows a comparison of the spectroscopic31,32 and photometric30 redshifts for 
objects brighter than i<26 including a sample of 168 spectroscopic redshifts at z>3 in 
the COSMOS field.   We found >40% of luminous z>4 objects are placed at z<2 by the 
photometric redshift method, including the extreme starburst presented here.  This is 
primarily due to photometric contamination from foreground sources.   When low-levels 
of flux are spuriously found in the photometry blue-ward of the 912Å break the 
photometric redshifts find a low-redshift solution.  However, we also found cases at 
fainter flux levels where a low redshift solution was preferred because the photometric 
limits could not rule it out.  
 
Supplementary Figure 1: A comparison of the photometric30 and spectroscopic31,32 
redshifts for faint objects in the COSMOS field is shown on the left. In addition to the 
previously published results, this plot includes 167 objects at z>3 and >2200 objects 
fainter than I>22.5.  In the right panel the photometric redshift distribution for 148 
objects with spectroscopic redshifts at z>4 is shown.  Note that 39.2% of objects are 
placed at z<3.  
Rather than suffer the limitations of the photometric redshifts we chose to use a 
colour selection to identify potential proto-cluster members.  The colour selection 
focuses on the region of the spectral energy distribution with maximum information.  
Furthermore, by limiting the number of filters used we avoid smoothing the images to 
the resolution of the worst seeing images and thereby maximizing the signal-to-noise of 
the photometry while minimizing contaminating light from foreground sources. 
  Photometry was measured using a procedure similar to that of the general 
COSMOS catalog21.  However, rather than matching the point spread function (PSF) to 
3” diameter apertures, the PSF homogenized images and a 1” and 2” diameter aperture 
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was used. A statistical aperture correction was then applied to each band to bring the 
aperture magnitudes into average agreement with the 3” PSF matched aperture 
photometry from the COSMOS catalogue21.   
A simulated photometric catalogue was used to define a z~5.3 selection criteria.  
The simulation assumed the measured evolution of the UV luminosity function between 
0<z<3 and no evolution at z>3.  The distribution of galaxy types and obscuration was 
matched to the comprehensive spectroscopic sample in GOODS-N.  However, the 
selection function is broadly insensitive to the exact assumptions made in the model, 
with decreased ages, decreased dust obscuration, and evolution at z>3 all narrowing the 
redshift distribution.   
Using this simulation, we defined our colour criteria as no detection in a 1” 
diameter aperture at >3σ significance in the u, B, g, and V bands along with colours of 
r-i>1 and IA738-i > 0.3.  This selects a combination of z=5.36±0.2 galaxies, galactic M, 
L, T stars and faint (low mass) z~0.85 galaxies with old stellar populations and/or large 
obscuration.   
Stars are easily removed because of their very red z-J colours but blue J-H 
colours.  Low mass galaxies are removed using the spectral bump at 1.6μm if they are 
sufficiently bright in the J,H,K and IRAC bands.  However, for objects fainter than 
H>23.5 ( i~25.5) (40% of our sample) we relied on the IRAC colours alone.   
The uncertainty in the selection method has little impact on the conclusions.  
The objects with confirmed redshifts contain 65% of the proto-cluster mass, still within 
the range expected for a proto-cluster.  Furthermore, the density of spectroscopically 
confirmed sources is significantly higher than that expected.  Excluding objects without 
firm J,H,K detections only reduces the mass by 21% since these fainter objects tend to 
be the least massive. 
4. Estimating the Magnitude and Significance of the Cluster 
 The significance of this cluster can be estimated from observational data33,34 and 
from cosmological simulations7.  Using our intermediate band colour selection to find 
galaxies at z=5.36±0.2 we find 8 objects in 1 square arc minute and 11 objects within a 
2 Mpc (0.93 arc minute) radius of COSMOS AzTEC-3 brighter than I<26 (L* at 
z=5.3)19.  These objects also meet the V and r dropout Lyman-Break criteria, but fall on 
the high-redshift end of these selections, so we consider V, r, and I band dropouts as 
comparison samples.      
A conservative estimate of the expected surface density can be derived using the 
Great Observatories Origins Deep Survey (GOODS) data19.  In these data a surface 
density of 0.75+/-0.04 galaxies per square arc minute brighter than z850<26.0 is found in 
the combined V-band and I-band dropout samples.  These samples cover a redshift 
range of 4.5<z<6.5, a factor of five more volume than our selection.  Furthermore, 
objects are brighter in the z850 filter than the I band, so the surface density is an over-
estimate for an I band selected sample.  However, even with this conservative estimate 
the region around COSMOS AzTEC-3 is over-dense by a factor of 11 in the 1 square 
arc minute region, and a factor of 5 within the 2 Mpc radius.   
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A better estimate of the significance can be obtained from the 4 square degree 
Canada-France-Hawaii Legacy Deep Survey (CFHT-LS Deep) data20.  These data find a 
surface density of 0.352+/-0.006 r-dropout (4.5<z<5.2) galaxies per square arc minute 
brighter than z’<26 and a 2-point correlation function described by a clustering length 
(ro) of 5.53 h-1 Mpc and a power-law index of γ=2.13. Using the correlation function we 
estimate a variance of 1.06 galaxies in a 2 Mpc radius circle over the redshift interval 
probed by the r-band dropouts20.  Using the mean density and variance, the cluster is 
11.5 times over-dense and has a significance of 9.5σ.  
The significance was also estimated using a simulated 2 square degree galaxy 
catalogue based on the Millennium simulation35.  From the possible semi-analytics in 
this simulation we chose the WMAP 3yr cosmology, Galaxy formation Model C, and 
Dust Model 2 which most closely match the observed properties of z>3 galaxies.  
Galaxies were selected form the simulated catalogue to match the redshift distribution 
of the observed samples20, and a magnitude limit of I<26.1 was adopted to match the 
observed object surface densities20.  For the r-dropout selection function and a 2 Mpc 
radius cell we find a mean galaxy density of 0.94 and a variance of 1.14 galaxies per 
cell, meaning the observed cluster is an 11.7 times over-density with a significance of 
8.8σ.   
Alternatively, using the intermediate band selection function of z=5.36±0.2 we 
find a mean galaxy density of 0.14 and a variance of 0.39 galaxies per cell, a factor of 
78.6 over-density, formally significant at 27.8σ.  However, if we scale the r-band 
dropout surface density to the volume of the intermediate band selection and assume the 
same clustering properties, we find the significance is only 14.4σ.   
Finally, if we consider only the three spectroscopically confirmed galaxies, a 
redshift interval of 5.3±0.005, and the measured r-band dropout clustering and space 
density we expect 0.024 galaxies in the 2Mpc cell with a variance of 0.19, implying a 
factor of 125 over-density significant at 16.7σ. 
In summary, we find this region is over-dense by a factor of >11 at the >9σ 
level, with the spectroscopic sub-sample suggesting an even higher significance.  
5. Estimating Stellar Masses  
To determine stellar masses models24 were fit to the data red-ward of the Lyman-
alpha forest break at rest frame 1216Å.  These data included the IA827, NB816, z+, J, 
H, and Ks band photometry from the COSMOS catalog21, and the IRAC 3.6μm and 
IRAC 4.5μm band photometry presented here.  In the case of the extreme starburst the 
IRAC 5.8μm and 8.0μm detections29 were also used.  The properties of the proto-cluster 
members within 2 Mpc of the starburst are given in Supplementary Table 1.  The optical 
ID numbers and positions are those from the COSMOS catalog21, while the 3.6μm and 
4.5μm fluxes are derived from the new Spitzer data described in supplementary section 
1.  The ages, dust obscuration (Av), and Masses are determined from our model fitting 
and are accurate to 3 Myr, 0.2 magnitudes and 0.3 dex respectively, however these 
errors are highly correlated and subject to systematic uncertainties in the underlying 
stellar population models.   
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Supplementary Table 1: Model fitting results 
Optical 
ID 
RA 
J2000 
DEC 
J2000 
Age 
(Myr) 
Av 
(Mag) 
Stellar Mass  
(log10[M

]) 
3.6μm flux 
(nJy) 
4.5μm flux 
(nJy) 
 
1445777 150.09148 2.602377 3 1.4 9.1 336±46 256±64 
1445840 150.0937 2.600853 3 0.25 7.8 <38 <44 
1446425 150.0839 2.598316 2.5 0.25 7.9 <38 <44 
1446767 150.08328 2.595851 4.5 1.5 9.3 344±46 431±64 
1447523 150.08573 2.589246 3 0.85 8.8 348±52 145±66 
1447524* 150.08958 2.575765 8 0.5 9.5 1372±48 2039±66 
1447526 150.08654 2.586426 10 0.4 9.4 563±46 717±46 
1447531*+ 150.08625 2.58933 10 0.8 10.0 1419±48 2159±68 
1448834 150.08309 2.588966 9 1.0 9.2 169±46 407±64 
1449472 150.07305 2.582372 9 0.6 9.3 372±46 708±64 
*Spectroscopically confirmed   
+Starburst 
 
6. Estimating The Infrared Luminosity of COSMOS AzTEC-3 
The infrared luminosity was estimated empirically from the mm, radio limits, 
and CO line fluxes.  The 1.1mm continuum measurement yields Far Infrared (60-
120μm) luminosities (LFIR) between 0.9-2 x1013 L assuming sub-mm slopes of 3.5 and 3 respectively. The actual spectral slope is constrained to be >3 at long wavelengths by 
the 870μm, 1.1mm and 2mm measurements14,15 along with the 2.7, 3.2, and 8.2mm 
continuum limits obtained with the CO measurements8, suggesting the source is cold 
and of lower intrinsic luminosity. 
Evidence for cold dust is also supported by the flux ratios of the 870μm to 
3.3mm data.  The 870μm fluxes yield LFIR values that are 30% lower than those 
obtained with the 1.1mm flux alone and the 1.1mm flux yields a LFIR 80% lower than 
the 2mm flux alone.  The 870μm data are near the dust emission peak at this redshift, 
and hence are likely to under-estimate LFIR if the dust temperature is low.  Furthermore, 
the 1.1-3.3mm LFIR estimates are only consistent if the sub-mm spectral slope is >3.5.  
Using the LFIR to radio correlation16,36 with q=2.35 and a spectral slope of -0.8, 
we estimate LFIR <1.5 x1013 L.  Instead, using the L’CO- LFIR relation37 we find LFIR=1.3 x1013 L.  
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Fitting models to the 24μm through radio photometry yields similar results given 
in Supplementary Table 2 and shown in Supplementary Figure 2.  We note that the 
scatter in model estimates of LIR is much greater than the estimates of LFIR.  This reflects 
differing assumptions in the models since the data does not constrain rest frame 
wavelengths shorter than 140μm.  
Combing these estimates we find LFIR=1.7±0.8x1013 L.  
Supplementary Table 2: Infrared model fitting results 
Template Model Name χ2 LFIR (60-120µm) (L) LIR(8-1000µm) (L) 
Chary & Elbaz38 LIR=1012.15 2.4 2.3x1013 6.8x1013 
Dale & Helou39 1.1875 2.2 3.2 x1013 1.1x1014 
Lagache Hot40 LIR=109 11.5 1.6 x1013 3.4x1013 
Lagache Cold40 LIR=109.2 6.9 6.9 x1012 2.2x1013 
 
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Supplementary Figure 2: The spectral energy distribution of COSMOS AzTEC-3 is 
shown along with model fits24,38,39,40.  Error bars are 1σ including standard measurement 
error and systematic flux calibration error.  The optical, near and mid-infrared, and radio 
data are taken from the COSMOS survey16,21,29, with newly acquired warm IRAC data 
used at 3.6 and 4.5μm.  The 0.87 and 1.1mm fluxes are taken from the sub-mm imaging 
survey14,15, wile the 2mm data point presented here was acquired with the GISMO 
camera on the IRAM 30m telescope.  The 2.7, 3.3, and 8.2mm flux limits are from the 
CO 6-5, 5-4, and 2-1 measurements8.  The best-fit stellar mass is 1.0±0.3 x1010 solar 
masses with Av=0.8 and an age of 10Myr.  The best fit Far-Infrared (60-120μm) 
luminosity ranges from  0.9-3.2 x1013 solar luminosities depending on the model 
assumptions.  However, the 3mm upper limits, the radio flux limit, and the CO 
luminosity favor lower luminosities.  
Supplementary References 
29. Sanders, D.B et al. S-COSMOS: The Spitzer Legacy Survey of the Hubble 
5Space Telescope ACS 2 deg2 COSMOS Field I: Survey Strategy and First 
Analysis. Astrophys. J. Supp., 172, 86-98 (2007).  
30. Ilbert, O. et al. COSMOS Photometric Redshifts with 30-bands for 2-deg2. 
Astrophys. J., 690, 1236-1249 (2009). 
31. Lilly, S.J. et al. The zCOSMOS 10k-Bright Spectroscopic Sample. Astrophys. J. 
Supp., 184, 218-229 (2009) 
32. Trump, J. R. et al. Magellan Spectroscopy of AGN Candidates in the COSMOS 
Field. Astrophys. J. Supp., 172, 383-394 (2007) 
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33. Somerville, R.S. et al. Cosmic Variance in the Great Observatories Origins Deep 
Survey. Astrophys. J. Lett., 600, 171-174 (2004). 
34. Robertson, B.E. Estimating Luminosity Function Constraints from High-
Redshift Galaxy Surveys. Astrophys. J., 713, 1266-1281 (2010). 
35. Wang J., et al. The dependence of galaxy formation on cosmological 
parameters: can we distinguish between the WMAP1 and WMAP3 parameter 
sets? Mon. Not. R. astro. Soc., 384, 1301-1315 (2008). 
36. Carilli, C. & Yun, M. The Scatter in the Relationship between Redshift and the 
Radio-to-Submillimeter Spectral Index. Astrophys. J., 530, 618-624 (2000) 
37. Riechers, D. et al. CO(1-0) in z >~ 4 Quasar Host Galaxies: No Evidence for 
Extended Molecular Gas Reservoirs. Astrophys. J., 650, 604-613 (2006) 
38. Chary, R. & Elbaz, D. Interpreting the Cosmic Infrared Background: Constraints 
on the Evolution of the Dust-enshrouded Star Formation Rate. Astrophys. J., 
556, 562-581 (2001) 
39. Dale, D. & Helou, G. The Infrared Spectral Energy Distribution of Normal Star-
forming Galaxies: Calibration at Far-Infrared and Submillimeter Wavelengths. 
Astrophys. J., 576, 159-168 (2002) 
40. Lagache, G., Dole, H., & Puget, J.-L. Modelling infrared galaxy evolution using 
a phenomenological approach. Mon. Not. R. astro. Soc., 338, 555-571 (2003). 
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Crossref

Nature

Capak, P.

Riechers, D.

Scoville, N.

Carilli, C.

Cox, P.

Neri, R.

Robertson, B.

Salvato, M.

Schinnerer, E.

Yan, L.

Wilson, G.

Yun, M.

Civano, F.

Elvis, M.

Karim, A.

Mobasher, B.

Staguhn, J.

MPG.PuRe

This is the pre-published version harvested from ArXiv. The published version is located at http://www.nature.com/nature/journal/v470/n7333/full/nature09681.htmlMassive clusters of galaxies have been found that date from as early as 3.9 billion years1 (3.9 Gyr; z = 1.62) after the Big Bang, containing stars that formed at even earlier epochs2, 3. Cosmological simulations using the current cold dark matter model predict that these systems should descend from ‘protoclusters’—early overdensities of massive galaxies that merge hierarchically to form a cluster4, 5. These protocluster regions themselves are built up hierarchically and so are expected to contain extremely massive galaxies that can be observed as luminous quasars and starbursts4, 5, 6. Observational evidence for this picture, however, is sparse because high-redshift protoclusters are rare and difficult to observe6, 7. Here we report a protocluster region that dates from 1 Gyr (z = 5.3) after the Big Bang. This cluster of massive galaxies extends over more than 13 megaparsecs and contains a luminous quasar as well as a system rich in molecular gas8. These massive galaxies place a lower limit of more than 4 × 1011 solar masses of dark and luminous matter in this region, consistent with that expected from cosmological simulations for the earliest galaxy clusters4, 5, 7.233-23

A Massive Protocluster Of Galaxies At A Redshift Of Z ≈ 5.3

CO(1-0) in z >~ 4 Quasar Host Galaxies: No Evidence for Extended Molecular Gas Reservoirs.

Cosmic Variance in the Great Observatories Origins Deep Survey.

COSMOS Photometric Redshifts with 30-bands for 2-deg

COSMOS Photometric Redshifts with 30-bands for 2-deg2.

Estimating Luminosity Function Constraints from HighRedshift Galaxy Surveys.

Interpreting the Cosmic Infrared Background: Constraints on the Evolution of the Dust-enshrouded Star Formation Rate.

Magellan Spectroscopy of AGN Candidates in the COSMOS Field.

Modelling infrared galaxy evolution using a phenomenological approach.

S-COSMOS: The Spitzer Legacy Survey of the Hubble

The dependence of galaxy formation on cosmological parameters: can we distinguish between the WMAP1 and WMAP3 parameter sets?

The Infrared Spectral Energy Distribution of Normal Starforming Galaxies: Calibration at Far-Infrared and Submillimeter Wavelengths.

The Scatter in the Relationship between Redshift and the Radio-to-Submillimeter Spectral Index.

The zCOSMOS 10k-Bright Spectroscopic Sample.

http://authors.library.caltech.edu/22548/2/nature09681-s1.pdf