Will the Dark Energy Survey measure neutrino masses? http://www.darkenergysurvey.org

OutlineDES: what is it and

update + probes usedNeutrino masses from

DES

The Dark Energy Survey (DES)Proposal:

◦ Perform a 5000 sq. deg. survey of the southern galactic cap

◦ Measure dark energy with 4 complementary techniques

New Instrument:◦ Replace the PF cage

with a new 2.2 FOV, 520 Mega pixel optical CCD camera + corrector

Time scale:◦ Instrument Construction

2008-2011Survey:

◦ 525 nights during Oct.–Feb. 2011-2016

◦ Area overlap with SPT SZ survey and VISTA VHS

Use the Blanco4m Telescope at the Cerro TololoInter-American Observatory (CTIO)

The DES Collaborationan international collaboration of ~100 scientists from ~20 institutions

US: Fermilab, UIUC/NCSA, University of Chicago,LBNL, NOAO, University of Michigan, University of Pennsylvania, Argonne National Laboratory, Ohio State University, Santa-Cruz/SLAC Consortium

Observatorio Nacional, CBPF,Universidade Federal do Rio de Janeiro, Universidade Federal do Rio Grande do Sul

Brazil Consortium:

UK Consortium:UCL, Cambridge, Edinburgh, Portsmouth, Sussex, Nottingham

Spain Consortium:CIEMAT, IEEC, IFAE

CTIO

DES Organization

SupernovaeB. NicholJ. Marriner

ClustersJ. MohrT. McKay

Weak LensingB. JainS. Bridle

Galaxy ClusteringE. GaztanagaW. Percival

Photometric RedshiftsF. CastanderH. Lin

SimulationsA. KravtsovA. Evrard

TheoryW. HuJ. Weller

Strong LensingE. Buckley-GeerM. Makler

Galaxy EvolutionR. WechslerD. Thomas

QSOsR. McMahonP. Martini

Milky WayB. SantiagoB. Yanny

11 Science Working Groups

Over 100 scientistsfrom the US, UK, Spain and Brazil

The DES Instrument: DECam DECam Focal Plane

3 sq. deg. field of view (~ 0.5 meter diameter focal plane)62 2kx4k Image CCDs: 520 MPix8 2kx2k Alignment/focus CCDs4 2kx2k Guide CCDs

The 5 lenses are now being polished

C2

Polishing & coating coordinated by UCL (with 1.7M STFC funding)

C1

Design: 5 lensesLargest is~ 1m diameterSmallest is ~ 0.5m

Polishing started in May 2008 Est. Delivery May 2010

DES CCDs 62 2kx4k fully

depleted CCDs: 520

Megapixels Excellent red

sensitivity Developed by

LBNL

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Wavelength (nm)

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Thinned CCD Deep DepletedLBNL high resistivity

Full size prototype imager used for integration testing out at Sidet (Fermilab)

9

DECam parts in Fabrication: Shutter

Bonn University and Argelander Institute in Germany is making the DES Shutter

Opening is ~ 600mm diameter

The DECam Shutter is the largest ever (so far)

Earthquake!!!No damage to

telescopeGiven that and

timeline of CCD’s and corrector -> first light should be late next year

Dark Energy Science Program

Four Probes of Dark EnergyGalaxy Clusters

• clusters to z>1• SZ measurements from SPT• Sensitive to growth of structure and geometry

Weak Lensing• Shape measurements of 300 million galaxies • Sensitive to growth of structure and geometry

Large-scale Structure• 300 million galaxies to z = 1 and beyond• Sensitive to geometry

Supernovae• 15 sq deg time-domain survey• ~3000 well-sampled SNe Ia to z ~1• Sensitive to geometry

Plus QSOs, Strong Lensing, Milky Way, Galaxy Evolution

Synergy with VISTADES recovers V in VISTA!DES will provide the visible and Vista the IR counterpart

DES grizDES

10 Limiting Magnitudes g 24.6 r 24.1 i 24.0 z 23.9

+2% photometric calibrationerror added in quadrature

Galaxy Photo-z Simulations

+Developed improved Photo-z & Error Estimates and robust methods of outlier rejectionCunha, Lima, Frieman, Lin and Abdalla, Banerji. Lahav

Z 23.8Y 21.6

+VHS

DES griZY +VHS JHKs onESO VISTA 4-menhances science reach

*Vista Hemisphere Survey

J 20.3H 19.4Ks 18.3

ANNz; low depth survey: trainingsets in place

DES Forecasts: Power of Multiple Techniques

Assumptions:Clusters: 8=0.75, zmax=1.5,WL mass calibration

BAO: lmax=300WL: lmax=1000(no bispectrum)

Statistical+photo-z systematic errors only

Spatial curvature, galaxy biasmarginalized,Planck CMB prior

w(z) =w0+wa(1–a) 68% CL

geometric

geometric+growth

DETF Figure of Merit: inversearea of ellipse

Stage II notincluded here

DES will also constrain the neutrino mass

We have made simulations for this with Des photometric redshifts

We have also measured this from the current SDSS survey. (cosmological results presented by Thomas Tues.)

I will go through the assumptions and present the forecasts.

Neutrinos as Dark Matter

• Neutrinos are natural DM candidates

• They stream freely until non-relativistic (collisionless phase mixing) Neutrinos are HOT Dark Matter

• First structures to be formed when Universe became matter -dominated

• Ruled out by structure formation CDM

eV 46 m 1 Ω eV 93.2

mhΩ

iiν

ii

2ν

MpceV 30

m 41

-1

ν

Neutrino Free Streaming

F

b, cdm

n

Measuring the clustering with Photo-z

Photo-z distribution

Looking at techniques in real data:The 2SLAQ & MegazLRG. (Pathfinder with DES)

2SLAQ galaxies selected from the SDSS survey. Mainly red galaxies at redshift ranging from 0.4 to 0.7.

Even though photo-z are good for LRG given large 4000A break different techniques give different accuracies

13000 galaxies from 2SLAQ. ~8000 for training ~5000 to calibrate the histogram

Ab

dalla

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8

DES+VISTA would improve photo-z by a factor of 2 for z> 1What is the effect on WL, BAO, SNIa Science?

Banerji, Abdalla, OL & Lin 0711.1059

DES (5 filters) vs. DES+VISTA(8 filters)

Already seen earlier this weekThomas et al. 0911.5291

WMAP red: bound is ~1.3eV. (all 95%)+ BAO+SNe: blue 0.69eV + MegaZ : yellow 0.65eV + BAO+SNe+MegaZ+HST: green 0.28eV

Neutrino mass from DES+Planck

Lahav, Kiakotou, Abdalla and Blake(0910.4714)DES + Planck 5 times more constraining than WMAP + MegaZDES will have many galaxy types (~30 or so) to do this experiment -> important for galaxy bias

Two simulations used:Input: M =0.05 eV and 0.25eV

Error: 0.12 eV 95% (Only DES + Planck) on both simulations. Without any further data (BAO, SNe, clusters, etc…)

Total Neutrino Mass DES vs. KATRIN M< 0.1 eV M < 0.6 eV

t

Goal: 0.05 eVOther cosmological probes of the neutrino mass: weak lensing, CMB lensing, etc…

ConclusionsDES under construction:

◦ Lenses being polished◦ CCD’s being tested◦ Should have first light late next year

Science predicts a increase in our knowledge in w0-wa plane

Also increase in our knowledge in the neutrino mass:◦ Same experiment done on SDSS LRG’s

m_nu < 0.28eV◦ For DES m_nu < 0.12eV with Planck only.◦ All these have to be taken with a pinch of salt…

but…