Galaxy formation with thePFS Cosmology BAO Survey:
Potential for Hybrid Strategies(more than one way to the top of Mauna Kea)

Kevin Bundy(Hubble Fellow, UC Berkeley)
SuMIRe Workshop, December 2010
Friday, December 10, 2010

A PFS Cosmology Survey thought experiment:

Goals:
1. Enable breakthrough galaxy science.
2. Maximize unique potential for cosmology.

Friday, December 10, 2010

The galaxy formation fantasy is the SDSS at z~1
Spec-z survey Wish List
1. Mass complete to z~1.. > log M = 10.5
2. SDSS like volume. V > 0.2 Gpc3
3. High sampling/success rate.. > 70%
4. Strong S/N.. > 10
5. Wide wavelength range
6. Blue sensitivity

Be realistic... DEEP2 took over 100 nights on KeckFriday, December 10, 2010

Cosmologist’s desires are BAO at z~1

BAO requirements
1. Volume! V > 5 Gpc3 for 5% σw
2. Sampling 2e10-4 < n < 4e10-4
3. S/N ~ 1-3

Friday, December 10, 2010

A problem marriage for BAO and galaxy formation

BAO requirements... for galaxy formation

1. Volume! V > 5 Gpc3 for 5% σw

Way overkill (only want 0.2)

2. Sampling 2e10-4 < n < 4e10-4

Log M=11.3 (not 10.5), or not complete

3. S/N ~ 1-3

Too low for extracting spectral info
(need 10)

Let’s choose both!

Friday, December 10, 2010

z=1.6PFS BAO Survey
3000 deg2, 9 Gpc3
Fiber density: 1500 deg-2
Field of view: 1.8 deg2
R < 23 (OCDD)

z = 1.0

z = 0.6(little)BOSS
10,000 deg2, 1.5e6
LRGs,14 Gpc3

Friday, December 10, 2010

Sloan, 9830 deg2,1e6 galaxies
0.2 Gpc3

z = 0.1z=1.6PFS BAO Survey
3000 deg2, 9 Gpc3
Fiber density: 1500 deg-2
Field of view: 1.8 deg2
R < 23 (OCDD)
BigBOSS
14,000 deg2 30 Gpc3
Fiber density: 715 deg-2
Field of view: 7 deg2

z = 1.0

z = 0.6(little)BOSS
10,000 deg2, 1.5e6
LRGs,14 Gpc3

Friday, December 10, 2010

Sloan, 9830 deg2,1e6 galaxies
0.2 Gpc3

z = 0.1z=1.6PFS BAO Survey
3000 deg2, 9 Gpc3
Fiber density: 1500 deg-2
Field of view: 1.8 deg2
R < 23 (OCDD)
BigBOSS
14,000 deg2 30 Gpc3
Fiber density: 715 deg-2Field of view: 7 deg2

6.5 Gpc3

z = 1.0

2.3 Gpc3
300 deg-2
z = 0.6(little)BOSS
10,000 deg2, 1.5e6
LRGs,14 Gpc3

Friday, December 10, 2010

Sloan, 9830 deg2,1e6 galaxies
0.2 Gpc3

z = 0.1z=1.6PFS BAO Survey
3000 deg2, 9 Gpc3
Fiber density: 1500 deg-2
Field of view: 1.8 deg2
R < 23 (OCDD)
BigBOSS
14,000 deg2 30 Gpc3
Fiber density: 715 deg-2
Field of view: 7 deg2

Solution conceptz = 1.0z = 0.6(little)BOSS
10,000 deg2, 1.5e6LRGs,14 Gpc3

Friday, December 10, 2010

Sloan, 9830 deg2,1e6 galaxies
0.2 Gpc3

z = 0.1z=1.6PFS BAO Survey
3000 deg2, 9 Gpc3
Fiber density: 1500 deg-2
Field of view: 1.8 deg2
R < 23 (OCDD)
BigBOSS
14,000 deg2 30 Gpc3
Fiber density: 715 deg-2
Field of view: 7 deg2

Solution conceptz = 1.0z = 0.6(little)BOSS
10,000 deg2, 1.5e6
LRGs,14 Gpc3

Friday, December 10, 2010

Sloan, 9830 deg2,1e6 galaxies
0.2 Gpc3

z = 0.1z=1.6PFS BAO Survey3000 deg2, 9 Gpc3
Fiber density: 1500 deg-2
Field of view: 1.8 deg2
R < 23 (OCDD)
BigBOSS
14,000 deg2 30 Gpc3
Fiber density: 715 deg-2
Field of view: 7 deg2

Solution concept
Higher-z unique BAO
1200 fibers, n=4e-4z = 1.0

z = 0.6(little)BOSS
10,000 deg2, 1.5e6
LRGs,14 Gpc3

Friday, December 10, 2010

Sloan, 9830 deg2,
1e6 galaxies
0.2 Gpc3

z = 0.1z=1.6PFS BAO Survey
3000 deg2, 9 Gpc3
Fiber density: 1500 deg-2
Field of view: 1.8 deg2
R < 23 (OCDD)
BigBOSS
14,000 deg2 30 Gpc3
Fiber density: 715 deg-2
Field of view: 7 deg2

Solution concept
Higher-z unique BAO
1200 fibers, n=4e-4z = 1.0Lower sampling BAO,
150 fibers, n=1.5e-4z = 0.6(little)BOSS
10,000 deg2, 1.5e6
LRGs,14 Gpc3

Friday, December 10, 2010

Sloan, 9830 deg2,
1e6 galaxies
0.2 Gpc3z = 0.1

z=1.6PFS BAO Survey
3000 deg2, 9 Gpc3
Fiber density: 1500 deg-2
Field of view: 1.8 deg2
R < 23 (OCDD)
BigBOSS
14,000 deg2 30 Gpc3
Fiber density: 715 deg-2
Field of view: 7 deg2(little)BOSS
10,000 deg2, 1.5e6
LRGs,14 Gpc3

Friday, December 10, 2010

Sloan, 9830 deg2,1e6 galaxies
0.2 Gpc3

Solution concept
Higher-z unique BAO
1200 fibers, n=4e-4z = 1.0Lower sampling BAO,
150 fibers, n=1.5e-4
z = 0.6

Embedded “shell” galaxy survey
700 fibers
z = 0.1z=0.65z=0.55300 Mpc

A mass-complete galaxy shell survey• Log M > 10.5, 0.2 Gpc3
• 90% sampling rates (DEEP2 was 30%)
• 1% clustering at 100 kpc → unique territory and science• Bright galaxies (i<22) S/N ~ 8-10 → velocity dispersions, chemistry• Covers all key lines: Ha, NII, OIII, Hb, OII, etc. → AGN, SFH, balmer decrement• 0.2 Gpc3 → Vanishing cosmic variance, statistics on rare samples

This is the galaxy survey Wish List!

Friday, December 10, 2010

z=0.65z=0.55

How to do it? Survey Strategy...

!
$%-/#'%$!-%.01#./'!$%2#31!

300 Mpc"#$%!&#%'$!&#(%)*&%$!+,45'-#*+(6%.-!2,%.-)+4%-%)!7"&4• Aggressive fiber re-deployment, 1minutebright targets: i<21, 5 min, S/N 10
fainter targets: 21< i < 22, 30 min, S/N 10• 2500 shell galaxies per PFS pointing• 4.5e6 shell galaxies over 3200 deg2
• Robust photo-z selection from HSC
Synergy with HSC medium-band surveys!

!"#$%&'()*+(,!"#$%&!'#()*)#+,%!(*&-,!-,#.,*%/0!%,(12*)+-!3)$,%!4&*%#2!&%,&0!&+5!+,)-6$#%)+4#()*)#+,%(!)+!72#(,!4&78,5!6,9!4&**,%+:!
!

Friday, December 10, 2010

z=0.65z=0.55

Unique science from high samplingin the shell
1. Identification of group/cluster satellites & filaments
Half of low-mass SDSS satellites fiber collided
Detailed environmental studies
Cluster (ACT) masses, velocity dispersion masses
compared to lensing, confirmed richness
Dark matter profiles
2. Gas and galaxy formation: Cross correlation withabsorbers (background QSO/galaxies)
3. Spec-z mergers, dV distributions
4. New cosmology probes

Friday, December 10, 2010

300 Mpc

z=0.65

300 Mpc

z=0.55Unique science from high samplingin the shell

1. Identification of group/cluster satellites & filaments
Half of low-mass SDSS satellites fiber collided
Detailed environmental studies
Cluster (ACT) masses, velocity dispersion masses
compared to lensing, confirmed richness
Dark matter profiles
Figure 2: A demonstration of theM/N technique using the HOD. Panel (a): The filled circles represent
Figure2: A demonstration of the M/N technique using the HOD. Panel (ameasurements of w (r ) for galaxies with M < −20.5 in SDSS DR7 (Zehavi et al. 2010). The solid curves
measurementsof w (r ) for galaxies with M < −20.5 in SDSS DR7 (Zehavi
2. Gas and galaxy formation: Cross
correlation
are different
fits to thesewith
data using the HOD formalism but assuming different values of σ when calculating
are different fits to these data using the HOD formalism but assuming differen
halo statistics. Panel (b): The mean occupation numbers, "N # , that produced the best-fit w (r ) curves inabsorbers (background QSO/galaxies)
halo statistics. Panel (b): The mean occupation numbers, "N # , that produce(a). Dashed curves show the occupation of satellite galaxies. Panel (c): The prediction each model makes for(a). Dashed curves show the occupation of satellite galaxies. Panel (c): The pr
3. Spec-z mergers, dV distributions
M/N (here N is the number of satellite galaxies). The filled circles show M/N measured from the maxBCG
M/N (here N is the number of satellite galaxies). The filled circles show M/Ncluster catalog of Koester et al. (2007), with weak-lensing mass estimates of Sheldon et al. (2009b). Thecluster
catalog of Koester et al. (2007), with weak-lensing mass estimates o4. New cosmology probes
curves in this panel are only examples; in the analysis of T10, Ω is also a free parameter and we marginalize
pp

r

p

p

r

8

M

pp
M

m
curves in this panel are only examples;in the analysis of T10, Ωm is also a freeover a number of theoretical and observational uncertainties.
over a number of theoretical and observational uncertainties.

J. Tinker

Friday, December 10, 2010tion. Thus, to match the same observed level of clustering, the HOD must also change. Figures 2ation. Thus, to match the same observed level of clustering, the HOD m
and 2b show four
HOD models
oftheclusteringof M−20.5 galaxies
in SDSS. All fourr < using
Figuredifferent
3: Left: Constraints
in theΩm -σfrom cluster
countsmaxBCG
catalog
8 planeand 2bshow
fourdifferent
HODmodels theof theclusteringof Mr < −20.
(from Rozoet al. σ2010)
and fromthe 0.6
M/Ntotechniquein thisdemonstrates
proposal (from T10).
constraints axis between
are good fits, eventhoughfrom1.0. This
the Bothdegeneracy8 varies
aregoodfits,eventhoughσvaries
from0.6
to1.0.
This
demonstratest
WMAP7 priors and use the same cluster sample. 8In T10, the median cluster redshift iscosmology andassume
bias—real-spaceclusteringcannotdifferentiate
betweenthese models.
However, asz = 0.25, while the redshiftforthew(r)measurements
is
∼
0.1;
thus,
we
marginalize
overany
cosmology andp p bias—real-space clustering cannot differentiate between
σ8 decreases, possible
the bias
requiredmatch
clustering
increases.
To theincrease
evolutionin thetoHOD.
The thegreenobserved
contours are
the constraints
derived from
M/N the bias ofσ
decreases,
thebiasrequired
to matchthe observed
clustering increa
8the cluster sample
technique assuming
andinthehighly-biased
wp (rp ) measurementsare (a.k.a.
at the same
redshift. A statistic
the galaxy population,
more thatgalaxies
are placed
halos
clusters).
galaxymoreof galaxies
are constraints
placed inexpected
highly-biased halos(This will be discussed thein §4.)
Right: population,
Preliminary estimate
the dark energythat is sensitive
theusingoverallmass
scaleof dark
matterconstraints
halos cantherefore
break (withthis degeneracy.
fromtoDES
the M/Nmethodcompared
to expected
fromcluster
thatis sensitivetothe overall massscale
of abundance
dark matter
halos can ther
Our second method
determineHOD
observationallyis to directly
the tomean number
a Plancktoprior).
We have theassumed
a simplified
model extrapolated
from localmeasure
measurements
Oursecondmethodtodetermine
theHODobservationallyis to directly
theof
M/N
estimates,
which weUnlike
expect tothe
be clustering,a conservative noestimate.
This preliminaryof galaxies in acalculate
samplemassiveclusters.
cosmology
is assumed in orderof galaxies
in a sampleof massive
clusters.
Unliketheclustering, no cos
calculation yields a factorof 2.3 improvementin the figureof merit overcluster counts
alone.
Notez=0.65
z=0.55Unique science from high samplingin the shell
1. Identification of group/cluster satellites & filaments
Half of low-mass SDSS satellites fiber collided
Detailed environmental studies
Cluster (ACT) masses, velocity dispersion masses
compared to lensing, confirmed richness
Dark matter profiles
2. Gas and galaxy formation: Cross correlation withabsorbers (background QSO/galaxies)
3. Spec-z mergers, dV distributions
4. New cosmology probes

Friday, December 10, 2010

300 Mpc

z=0.65

300 Mpc

z=0.55
12

A. Leauthaud
10.00010.000

0.100

10100

0.010

10100
smallscale clusteringd)e) 1! [arcsec]
1000

0.001
10.001

10100

1000

10.000w bin4w bin5

1.000

1000

1080.1000.100

z = [0.22,0.48]

60.0100.010

40.001

20.001110100! [arcsec]

1000 110100

1.00.8g)

2100.6

g-g bin1

0.2

10.00.0

1000

000.1

10-4

1010.20.4

SDSS, Li et al. 2009
SDSS, Baldry et al. 2008
SDSS, Panter et al. 2004.

-6

100.6

0.8

91011Log M*h702/MO•

1.01

galaxy-galaxylensingk)l)
1g-g bin5

1010-2102

1010.1
10-20.1j)g-g bin4

102

1010.112i)
g-g bin3

102

0.1

10-2

10COSMOS, this work

10-5

100.1

81g-g bin2

102

610-3h)1024f)

0.110-2210-2

mass function

0.410[ h72 MO• pc -2 ]

w(!)

1c)
w bin3

1.000

0.100

0.010

1.000

"#

1. Identification of group/cluster satellites & filaments
Half of low-mass SDSS satellites fiber collided
Detailed environmental studies
Cluster (ACT) masses, velocity dispersion masses
compared to lensing, confirmed richness
Dark matter profiles
2. Gas and galaxy formation: Cross correlation withabsorbers (background QSO/galaxies)
3. Spec-z mergers, dV distributions
4. New cosmology probesb)
w bin21.000

0.1000.010
0.00110.00010.000a)w bin11.000

Log dN/dlogM* [h723 Mpc-3 dex-1]

Unique science from high samplingin the shell

0.1

0.1

1g-g bin610-20.11m)
g-g bin7

102

101

1

0.1

0.1

1 10-20.1
1 10-2
Physical transverse distance R [ Mpc h72-1 ]0.1

1A. Leauthaud
Fig. 6.— Best fit model for the z redshift bin (blue solid line). Panels a) to e): amplitude of the angular correlation function
1a function of angular separation θ (in arcseconds) in stellar mass thresholds. Note that in this redshift bin, the amplitude of w atseperations is artificially deflated by integral constrainte (this is included in the fitted model however). Panel f): COSMOS stellar
function for log10 (M∗ ) > 8.7 (completeness limit for this redshift bin). For reference, in panel f), we also show the SDSS mass func
from Li & White (2009) (triple schecter fit, black dash-dash line), Baldry et al. (2008) (magenta dash-dot line) and from Panter e(2004) (firebrick, dash-dot-dot line). Panels g) to m): galaxy-galaxy lensing signal in stellar mass bins. Note that in panel l), there
negative data point represented by a grey square. The lensing signal is decomposed into four compoants: the baryonic term (red dotthe central one halo term (green dash-dash), the satellite one halo term (orange dash-dot), and the two halo term (grey dash-dot-dot-

Friday, December 10, 2010

due to the treatment of satellites. Note that ourSHMR only concerns centrals whereas PB is foreverything (including satellites). Assumes thatthe stellar mass only depends on the mass at infall, Minf all . Assumptions that we make that are
the same as Peter: Tinker et al mass function functional form for SHMR - we both include scatter. (cosmology?). Things that are different: - halo
mass def - IMF. More details on the assumptions

ForRedshift
evolution:comparew
Behroozi/Moster and Heymans.
Note that the scatter that is constrained includes m
surement error which can vary depending on the dset.

8.2. Influance of the various parameters• In Figure 13 and 14 we show how each of theSummary: Hybrid strategies to marry
galaxy and BAO science.
• Exploit unique power of Subaru for BAO byconcentrating on z > 1.0• An embedded shell at z=0.6 enables breakthrough,highly sampled galaxy science. Area, depth, and fiber
density well suited to BAO component.

Friday, December 10, 2010

SuMIReSummary: Hybrid strategies to marry
galaxy and BAO science.
• Exploit unique power of Subaru for BAO byconcentrating on z > 1.0• An embedded shell at z=0.6 enables breakthrough,highly sampled galaxy science. Area, depth, and fiber
density well suited to BAO component.

Friday, December 10, 2010

SuMIReFriday, December 10, 2010