Download GOODS: Great Observatories Origins Deep Survey

High Redshift Starbursts
Mauro Giavalisco
Space Telescope Science Institute
and the GOODS team
STScI/ESO/ST-ECF/JPL/SSC/Gemini/Boston U./U. Ariz./U. Fla./U. Hawai/UCLA/UCSC/IAP/Saclay/Yale/AUI
The Quest for the Early Galaxies
GOODS: Great Observatories
Origins Deep Survey
Giavalisco 2002 ARA&A
Ellis 1997 ARA&A
During the mid-90’s, with improved instrumentation, the
commissioning of the 8-m class telescopes, and the
repair of HST, a number of influential deep galaxy
surveys (CFRS, LBGS, HDF) uncovered two important
pieces of evidence:
1.
Normal, luminous galaxies (the bright end of the Hubble sequence) were
essentially in place by z~1

2.
Massive (M*) galaxies formed prior to z~1
The universe was well populated with star-forming galaxies at z~3

At z~1 these must be old and/or massive or both. Are these the progenitors of the
bright galaxies?
Earlier suggestions that the bulk of galaxies formation
occurred at z<1 and that “essentially no galaxies are to be
expected at redshifts z>1” (1993, actual quote) were
dismissed.
GOODS: Great Observatories
Origins Deep Survey
Lilly et al. 1995
Abraham et al. 1996
GOODS: Great Observatories
Origins Deep Survey
Star-forming galaxies at z~3
(Lyman Break Galaxiess)
Steidel, Giavalisco, Dickinson, Pettini & Adelberger 1996
Efficient star formation at z>2.5
GOODS: Great Observatories
Origins Deep Survey
Steidel, Adelberger, Giavalisco, Dickinson & Pettini 1999
GOODS: Great Observatories
Origins Deep Survey
Galaxy morphology at z~3
•Smaller
•Regulars,
•Irregulars,
•Merging,
•Spheroids?
•Disks?
•No Hubble Seq.
•No l-dependence
Giavalisco et al. 1994; Giavalisco et al. 1996;
Steidel, Giavalisco, Dickinson & Adelberger 1996;
Lowenthal et al. 1997; Dickinson 1998; Giavalisco 1998;
Papovich, Giavalisco, Dickinson, Conselice & Ferguson 2003
Papovich, Dickinson, Giavalisco, Conselice & Ferguson 2004
GOODS: Great Observatories
Origins Deep Survey
Some rates are relatively
low, ~ today’s spirals;
others are prodigiously
high
Metallicity ~1/10 to ~ solar
Still an open issue
UV-star formation rates
GOODS: Great Observatories
Origins Deep Survey
The birth of the GOODS
• No Hubble Sequence apparently observed at z>2.
When and how did it form?
• What kind of galaxies are LBGs
– Bursting dwarfs? Massive?
– What did they evolve into? How much stellar mass did
they contribute?
– Up to which redshift are there LBGs? When did SF on
galactic scale start?
• Are there other (non LBG selectable, I.e. non starforming or very obscured) galaxies at z>2?
• How does star formation occur and evolve?
GOODS: Great Observatories
Origins Deep Survey
The GOODS
Treasury/Legacy Mission
Aim:
to establish deep reference fields with public data sets from X-ray
through radio wavelengths for the study of galaxy and AGN evolution of the
broadest accessible range of redshift and cosmic time.
GOODS unites the deepest survey data from NASA’s Great Observatories (HST,
Chandra, SIRTF), ESA’s XMM-Newton, and the great ground-based
observatories.
Primary science goals:
•
•
•
•
•
The star formation and mass assembly history of galaxies
The growth distribution of dark matter structures
Supernovae at high redshifts and the cosmic expansion
Census of energetic output from star formation and supermassive black holes
Measurements or limits on the discrete source component of the EBL
Raw data public upon acquisition; reduced data released as soon
as possible
A Synopsis of GOODS
GOODS: Great Observatories
Origins Deep Survey
GOODS Space
GOODS Ground
•
• HST Treasury (PI: M. Giavalisco)
– B, V, i, z
(3, 2.5, 2.5, 5 orbits)
– 400 orbits
– Δθ = 0.05 arcsec, or ~0.3 kpc at 0.5<z<5
– 0.1 sq.degree
– 45 days cadence for Type Ie Sne at z~1
• SIRTF Legacy (PI: M. Dickinson)
– 3.6, 4.5, 5.8, 8, 24 μm
– 576 hr
– 0.1 sq.degree
•
•
Chandra (archival):
– 0.5 to 8 KeV
– Δθ < 1 arcsec on axis
XMM-Newton (archival)
ESO, institutional partner (PI C. Cesarsky),
CDF-S
–
–
•
Keck, access through GOODS’ CoIs
–
•
•
•
Very deep U-band imaging
Gemini
–
–
•
Large-area BVRI imaging
NOAO support to Legacy & Treasury
–
•
Deep spectroscopic coverage
Subaru, access through GOODS’ CoI
–
•
Full spectroscopic coverage in CDF-S
Ancillary optical and near-IR imaging
Optical spectroscopy, HDF-N
Near-IR spectroscopy, HDF-S
ATCA, ultra deep (5-10 mJy) 3-20 cm
imaging, of CDF-S
VLA, ultra deep HDF-N (+Merlin, WSRT)
JCMT + SCUBA sub-mm maps of HDF-N
GOODS: Great Observatories
Origins Deep Survey
GOODS/ACS
B = 27.5
GOODS: Great Observatories
Origins Deep Survey
V = 27.9
i = 27.0
∆m ~ 0.3-0.6
AB mag; S/N=10
Diffuse source, 0.5” diameter
Add ~ 0.9 mag for stellar sources
HDF/WFPC2
B = 27.9
V = 28.2
I = 27.6
z = 26.7
In ~2-3 months we will release a new stack
of ~15 orbits in the z band, as well as ~50%
and ~30% more exp. time in the i and V bands,
in both fields, plus source catalogs (GOODS++)
GOODS: Great Observatories
Origins Deep Survey
•Theory predicts that dark
matter structures form at
z~20-30
•It does not clearly predict
galaxies, because we do not
fully understand star
formation
GOODS galaxies at High
Redshift
B435
V606
i775
z850
Unattenuated Spectrum
Spectrum Attenuated
by IGM
z~4
•Empirical information on
galaxy evolution needed to
the highest redshifts
•GOODS yielded the deepest
and largest quality samples
of LBGs at z~4 to ~6
B435 V606
z850
GOODS: Great Observatories
Origins Deep Survey
B-dropouts, z~4
LBG color selection
V-dropouts, z~5
Galaxies at z~6
GOODS: Great Observatories
Origins Deep Survey
Dickinson et al. 2003
(~6.8% of the cosmic age)
ACS/grism, Keck/LRIS & VLT/FORS2
observations confirm z=5.83
S123 #5144: m(z) = 25.3
Observed redshift distribution
GOODS: Great Observatories
Origins Deep Survey
#24
Z=5.78
Z=6.24?
Curves from full
numerical simulations
Giavalisco et al. 2004, 2005
V
Z=5.83
Spectra from
Bunker et al. 2003;
Stanway et al. 2003;
Vanzella et al. 2004
and the GOODS Team
GOODS: Great Observatories
Origins Deep Survey
LBG luminosity function
Apparently, very little evolution in the UV luminosity function
GOODS: Great Observatories
Origins Deep Survey
The history of the cosmic
star formation activity:
We find that at z~6 the cosmic
star formation activity was
nearly as vigorous as it was at
its peak, between z~2 and z~3.
NOTE: soon, nearly all GOODS will
have three times the original
exposure time in z band, and ~50%
more in i band (thanks to the Sne
program). Measure at z~6 will
significantly improve.
a=-1.6 assumed
Giavalisco et al. 2004
Giavalisco et al. 2005, in prep.
GOODS: Great Observatories
Origins Deep Survey
Still uncertainty on
measures
•LF still not well
constrained
•Clean z~6 color
selection still missing
•Cosmic variance still
not understood
•Will use SST data to
refine z~6 sample
•Will triple exp time
in GOODS
See also Bunker et al. 2004
Bouwens et al. 2004
GOODS: Great Observatories
Origins Deep Survey
SFR from X-ray emission
Lehmert et al 2005
See also Giavalisco 2002, ARA&A
GOODS: Great Observatories
Origins Deep Survey
Dust obscuration correction:
Calzetti starburst obscuration
law
B&C synthetic SED
Similar to what observed at
z~3
Star formation rates
z~4 B-band dropouts
SIRTF Imaging
GOODS: Great Observatories
Origins Deep Survey
GOODS
sensitivity
5-σ limiting flux μJy
5-σ limiting AB mag
0.11
26.3
0.21
25.6
1.35
23.6
1.66
23.4
20.0
20.7
Stellar mass & star formation
GOODS: Great Observatories
Origins Deep Survey
Mass: Rest-frame near-IR (e.g., rest-frame K-band at z~3), provides best
photometric measure of total stellar content
 Reduces range of M/L(l) for different stellar populations
 Minimizes effects of dust obscuration
Star formation: Use many independent indicators for to calibrate star formation
(obscured & open) in “ordinary” starbursts (e.g. LBGs) at z > 2.
• mid- to far-IR (SIRTF/MIPS); rest-frame UV (e.g, U-band); radio (VLA, ATCA); sub-mm
(SCUBA, SEST); nebular lines (spectroscopy)
PAH + continuum (24 mm)
Optical
+ near-IR
+ nebular lines
Stellar mass fitting
UV
Far IR
(GTO)
Measuring star formation
GOODS: Great Observatories
Origins Deep Survey
Rest-optical & -IR at z~6
• SST IRAC detections of z~6 galaxies
=> stellar population & dust fitting possible
ch1, 3.6mm
lrest=5300A
ch2, 4.5mm
lrest=6600A
Dickinson et al in prep
GOODS: Great Observatories
Origins Deep Survey
U- and B- dropouts have similar
UV-Optical color-magnitude
"trends”.
Rest-frame UV luminosity
density roughly comparable at z
~ 3 and 4.
Increase of ~33% in the restframe B-band luminosity density
from z ~ 4 to 3.
UV-Optical color reddens from z
~ 4 to 3, which implies an
increase in the stellar-mass/light
ratio.
Suggests that the stellar mass is
increasing by > 33% growth in B-
Luminosity Density versus
Color and Redshift
Papovich et al. 2003
increase of ~33%
Implications for Galaxy Evolution
GOODS: Great Observatories
Origins Deep Survey
Dickinson, Papovich, Ferguson, & Budavari 2003
Implications for Galaxy Evolution
GOODS: Great Observatories
Origins Deep Survey
Dickinson, Papovich, Ferguson, & Budavari 2003
Stellar mass is
building up
We still need to
know how this
growth depends
on the total mass
Total mass of individual
galaxies seems to evolve
less rapidly:
bottles form first, wine
is added later
GOODS; Papovich et al. 2004
Morphology of Lyman Break Galaxies at z~4
GOODS: Great Observatories
Origins Deep Survey
Sersic profile fits and Sersic indices:
[Ravindranath et al. 2005]
Irregulars: (n < 0.5)
Disks: (0.5 > n > 1.0)
Morphology of Lyman Break Galaxies at z~4
GOODS: Great Observatories
Origins Deep Survey
Bulges (n > 3.0)
Central compact component / point sources? (n = 5.0)
LBG morphology: light profiles
GOODS: Great Observatories
Origins Deep Survey
We measured the light
profiles and parametrized
them with the Sersic index
Ravindranath et al. 2005
GOODS: Great Observatories
Origins Deep Survey
Morphology of LBG
Theory predicts that when they form
undisturbed, galaxies are disks.
Images show a distribution of
morphology. Both spheroid-like
and disk-like morphology are
observed.
z=0 disks
z=0 spheroids
Ravindranath et al. 2005
GOODS: Great Observatories
Origins Deep Survey
Morphology of LBG:
the GINI and M20 coefficients
mergers
spheroids
Both spheroids and disk, as well as “transitional morphologies, observed.
Major mergers estimated at 15-25%, both at z~4 and z~1.4 (in agreement
with kinematics of close pairs with DEIMOS-DEEP –Lin et al. 2005)
Lotz, Madau, Giavalisco, Conselice & Ferguson 2005
Local galaxies at high redshift
GOODS: Great Observatories
Origins Deep Survey
Statistics calibrated using
local galaxies
Lotz et al. 2005
GOODS: Great Observatories
Origins Deep Survey
Lotz et al. 2005
LBG morphology
GOODS: Great Observatories
Origins Deep Survey
Lotz et al. 2005
LBG morphology
GOODS: Great Observatories
Origins Deep Survey
Lotz et al. 2005
LBG morphology
GOODS: Great Observatories
Origins Deep Survey
WFPC2 (HDF) and
NIC3 J and H images
Internal color dispersion
consistent with relatively
young and homogeneous
stellar population
Dickinson 1998
Papovich, Giavalisco, Dickinson,
Conselice & Ferguson 2004
Papovich, Dickinson, Giavalisco
Conselice & Ferguson 2004
Infrequent “morphological
k-correction”
GOODS: Great Observatories
Origins Deep Survey
The Evolution of galaxy
size
First measures at these redshifts
Testing key tenets of the theory
Galaxies appear to grow hierarchically
R~H(z)-2/3
Standard ruler
Ferguson et al. 2003
R~H(z)-1
GOODS: Great Observatories
Origins Deep Survey
Galaxy Clustering at High
Redshift
• Galaxies at high redshifts have “strong” spatial clustering,
I.e. they are more clustered than the z~0 halos “de-evolved
back” at their redshift.
– High-redshift galaxies are biased, I.e. they occupy only the most
massive portion of the mass spectrum (today, the bias of the mix is
b~1).
• Important:
– evolution of clustering with redshift contains information on how
the mass spectrum gets populated with galaxies as the cosmic time
goes on.
– Clustering of star-forming galaxies contains information on
relationship between mass and star formation activity
GOODS: Great Observatories
Origins Deep Survey
Giavalisco et al. 1998
Clustering of starforming galaxies at z~3
r0=3.3+/- 0.3 Mpc h-1
g = -1.8 +/- 0.15
Steidel et al. 2003
Adelberger et al. 1998
Strong clustering, massive halos
GOODS: Great Observatories
Origins Deep Survey
g=1.55
r0 =3.6 Mpc h-1
Porciani & Giavalisco 2002
Adelberger et al. 2004
GOODS: Great Observatories
Origins Deep Survey
local galaxies
m*>2.5E10 MO
m*>1.0E11 MO
LBGs
K20
EROs
sub-mm
SDSS
QSOs
Somerville 2004
GOODS: Great Observatories
Origins Deep Survey
Clustering segregation
mass drives LUV (SFR)
GOODS Ground
Lee et al. 2005
Adelberger et al. (1998, 2004)
Giavalisco et al. (1998)
Giavalisco & Dickinson (2001)
GOODS: Great Observatories
Origins Deep Survey
Clustering segregation at z~4
and 5
Clustering segregation is detected
In the GOODS ACS sample at z~4
Consistent with other measures, e.g.
Ouchi et al. 2004
Lee et al. 2005
GOODS: Great Observatories
Origins Deep Survey
We are observing
the structure within
the halo.
Break observed at
~10 arcsec
Note: 10 arcsec
at z~4 is about
~350 kpc.
See also Hamana
et al. 2004
Lee et al. 2005
Halo sub-structure at z~4
GOODS: Great Observatories
Origins Deep Survey
The Halo Occupation
Distribution at z~4
Consistent with Hamana et al. 2004
and Bullock et al. 2001
<Ng>=(M/M1)a
M>Mmin
Lee et al. 2005
1-s
2-s
GOODS: Great Observatories
Origins Deep Survey
a = 0.89 +/- 0.05
M1 = (4.74 +/- 0.50) x 1013 MO
Mmin = 6.10 x 1012 MO
From SDSS data
Zehavi et al. 2004
The Halo Occupation
Distribution at z~0
GOODS: Great Observatories
Origins Deep Survey
Halo substructure:
we observe an excess of faint
galaxies around bright ones.
massive halos contain more
than one LBG
“Bright Centers”:
z_850<24.0
“Faint centers”: 24.0< z_850 <24.7
“Satellites”:
z_850 >25.0
Lee et al. 2005
Halos and Galaxies at
z~3-5
GOODS: Great Observatories
Origins Deep Survey
Halos and Galaxies at
z~3-5
Clustering scaling in good agreement
with hierarchical theory
Implied halo mass in the range
5x1010 – 1012 MO
1-σ scatter between mass and SFR
smaller that 100%
Giavalisco & Dickinson 2001
Porciani & Giavalisco 2002
Lee et al. 2004, in prep.
GOODS: Great Observatories
Origins Deep Survey
EROs, or
UV-faint galaxies at z~2-3
Galaxies selected from near-IR
photometry [(J-K)>2.3]
A fraction would NOT be selected
by LBG criteria (UV selection)
However, overlap with LBG not quantified
and likely significant (see Adelberger
et al. 2004).
They appear in general more evolved, I.e.
more massive (larger clustering), with larger
stellar mass, more metal rich, and more dust
obscured) than LBGs. Occurrence of AGN
also seems higher.
At z~3 these galaxies have about
50% of the volume density of LBGs
(highly uncertaint). However; they
possibly contribute about up to 100%
of the LBG stellar mass density, because
they have higher M/L ratios
Van Dokkum et al. 2004
GOODS: Great Observatories
Origins Deep Survey
Ks< 22, R-Ks>3.35
Moustakas et al. 2004
EROs
EROs
GOODS: Great Observatories
Origins Deep Survey
•ACS resolution is crucial to
understand the nature of EROs
•Broad-band SED or statistical
morphology cannot discriminate
•Evidence of massive galaxies at z~1.2-1.5
Moustakas et al. 2004
GOODS: Great Observatories
Origins Deep Survey
Yan et al. 2004
HUDF/GOODS EROs
GOODS: Great Observatories
Origins Deep Survey
HUDF/GOODS EROs
Uses HUDF plus GOODS-SST data
SED fitting disfavour very dust
obscured, star-forming galaxies
SED better reproduced by a
two-component composite
populations:
an old, evolved one, plus
a low-intensity star-forming one.
Stellar mass relatively large:
1010 – 1011 MO
Evidence that similar objects
exist at z~7
(Mobasher et al. 2005)
Yan et al. 2004
GOODS: Great Observatories
Origins Deep Survey
Evidence of large stellar mass
at z~5, 6
Yan et al. 2005
LBGs at z~5 and 6
GOODS: Great Observatories
Origins Deep Survey
Evidence of large stellar mass
at z~5, 6
Yan et al. 2005
LBGs at z~5 and 6
GOODS: Great Observatories
Origins Deep Survey
An evolved, massive galaxy
at z~7?
HUDF + GOODS-SST
Mobasher et al. 2005, submitted to Nature
GOODS: Great Observatories
Origins Deep Survey
NIR-selected galaxies
NIR selected galaxies with K<20
VLT FORS spectra
SED fits show Mstar >1011 MO
Claims that NIR selection yields
more massive galaxies than UV
selection
Daddi et al. 2004
GOODS: Great Observatories
Origins Deep Survey
Near-IR selection
picks up the high-end
of the distribution of
masses (total and stellar)
Adelberger et al. 2004
Different populations?
Galaxies at z~1-0
GOODS: Great Observatories
Origins Deep Survey
Cosmic variance
Evolution of the integrated
mass density, M>1011 MO
GOODS data
Little evolution in the
stellar mass density
from z~1 to today
Note that at z~1 spirals dominated
stellar mass density; the opposite
at z~0: morphology transformation
Bundy, Ellis & Conselice 2005
Today’s stellar mass density
Ravindranath et al. 2003
–Sersic indices n<2
–Rest-frame MB <-19.5
–Photometric redshifts
GOODS: Great Observatories
Origins Deep Survey
Disk galaxy evolution from GOODS
Ravindranath et al. 2003
Number-densities are
relatively constant to z~1
Tendency for smaller
sizes at z~1 (30%
smaller)
The evolutionary link?
GOODS: Great Observatories
Origins Deep Survey
The expected evolution of clustering
(correlation length) suggests what the
high redshift galaxies might evolve into
at later epochs.
Giavalisco, 2002 ARA&A
Adelberger et al. 2004
GOODS: Great Observatories
Origins Deep Survey
Summary
• GOODS exploring fundamental issues of cosmic origins
• Large-scale star formation in place at less than ~7% of the cosmic time:
– SF galaxies observed to at least up z~7
– Massive galaxy started very early in the cosmic evolution
• Cosmic star formation (as traced by UV light) varies mildly at 3<z<6
– Universe is ~ as prolific a star former at z~6 as it is at z~3, after triplicating age
– Unclear proportion of obscured and evolved galaxies
– Obscured SF might contribute up to 100% of stellar mass density and star formation (2x)
• SF galaxies seem already diversified at z~4. “Evolved” galaxies up to z~7?
– Morphology mix includes spheroids, disks; 14-25% mergers at z~1.4-5
•
•
•
•
Direct evidence of growth of stellar mass from z~4 to z~1.
Galaxies get smaller at z>1; size evolution consistent with hierarchical growth
Massive galaxies in place at z~1; some galaxies are massive at z~2-3
Spatial clustering key to study relationship of star formation and dark matter:
–
–
–
–
Evidence of halo sub-structure at z~4. Transition at r~1 Mpc; Mmin~109 MO
Spatial clustering depends on UV luminosity, decreases for fainter galaxies
More massive halos host more star formation; scaling consistent with CDM spectrum
Implies relatively large total masses: 5x1010 – 1012 MO