The Survey and Synergies with CLASH

Ofer Lahav (University College London)

1 Outline

• Cosmology @ 2013 • Dark Energy on Mpc scales • The Dark Energy Survey (DES) • The Dark Energy Spectroscopic Instrument (DESI) • Combined Probes • DES-CLASH Synergies

2 The (known) unknown 95% of the universe Observational data: • Gravitational Lensing • Peculiar Velocities • Galaxy Clusters • CMB • Large Scale Structure • Type Ia Supernovae • Integrated Sachs-Wolfe

Physical effects: • Geometry • Growth of Structure 3 So what is Dark Energy?

• Systematics mimic DE? • Just Lambda-CDM? • Dynamical scalar field? • Signatures of modified gravity? • Inhomogeneous Universe? • Anthropic Principle? Multi-verse? • Something else unpredictable??

Planck CMB results support LCDM: “an almost perfect universe” or “a simple but strange universe”? 4

Redshift Distortion as a test of Dark Energy vs. Modified Gravity 2 ±g (k) = (b + f µ ) ±m(k) f = Ω°

5 Guzzo et al. 2008 Blake et al. 2011 Bound Systems (L-T-B)

Given observed r, v, t &Λ Can solve for M

Cf. spherical collapse: Lahav et al. (1991); Wang & Steinhardt (1998); Nandra, Lasenby & Hobson (2013)

Weighing the Local Group in the presence of Dark Energy Partridge, Lahav & Hoffman (arXiv:1308.0970, MNRAS) • At present the Milky Way and Andromeda are: * separated by r = 770 ±40 kpc * infall at v = -109 ±4 km/sec (Van der Marel 2012) • Given the age of the universe t=13.81 ± 0.06 Gyr and Dark Energy fraction of 69% (Planck 2013) 12 we find that the mass is (4.73 ± 1.03) x 10 Msun • Mass 13% higher than in the absence of Lambda cf. Kahn & Woltjer (1959); Lynden-Bell (1981) Chernin et al. (2009), Binney & Tremaine (2008) Mass calibration with 16 simulated galaxy pairs

• Mvir/Mta = 1.34 ± 0.26

• Mvir/MtaΛ = 1.04 ±0.16

• Estimate for LG: 12 Mvir /10 Msun = 4.92 ±1.08(obs) ±0.79(sys)

Partridge, Lahav & Hoffman (2013)CLUES simulations (Cf. Li and White 2008)

Timeline of cosmology projects 2010 2015 2020 2000 2005

MOS: 2dFGRS (e)BOSS DESI EUCLID

Imaging: SDSS DES LSST&EUCLID

$1 per galaxy! The Dark Energy Survey First Light in 9/12, Survey just started 9/13 w Multi-probe approach CTIO Cluster Counts Weak Lensing Large Scale Structure Supernovae Ia w 8-band survey 5000 deg2 grizY 300 million photometric redshifts + JHK from VHS VISTA +SPT SZ clusters

10

THE DES COLLABORATION

DES Science Committee w SC Chair: O. Lahav w Large Scale Structure: E. Gaztanaga & W. Percival w Weak Lensing: S. Bridle & B. Jain w Clusters: J. Mohr & C. Miller w SN Ia: M. Sako & B. Nichol w Photo-z: F. Castander & H. Lin w Simulations: G. Evrard & A. Kravtsov w Galaxy Evolution: D. Thomas & R. Wechsler w QSO: P. Martini & R. McMahon w Strong Lensing: L. Buckley-Geer & M. Makler w Milky Way: B. Santiago & B. Yanny w Theory & Combined Probes: S. Dodelson & J. Weller w + Spectroscopic task force: F. Abdalla & A. Kim w + Ad-hoc Committees

Regular WG telecons; Monthly SC telecons; sessions at collaboration meetings; reports to the DES Director, ExeC & MC 12 The Dark Energy Survey

DES FIRST LIGHT

NGC 1365

0.8” images recorded within first few nights of first light!

Fornax Cluster Highlights from DES earlyThe data BIGGER picture Mass & light maps of massive galaxy clusters from early DECam data

Bob Armstrong Elisabeth Krause David Bacon Huan Lin Keith Bechtol Niall McCrann Ken Patton Fabrice Brimioulle Andres Plazas Joseph Clampitt Barnaby Rowe Daniel Gruen Eduardo Rozo Michael Hirsch Eli Rykoff Klaus Honscheid Stella Seitz Eric Huff Eric Suchyta Bhuv Jain Rafal Szepietowski Mike Jarvis Vinu Vikram Stephanie Jouvel Julia Young Tomasz Kacprzak ... and the DES SV squad 7 confirmed SN, A new cluster Mass Peter Melchior 5 of them SNIa @ z= 0.87 reconstruction of cluster RXJ2248 @z=0.35

A142 @ z=0.25 DES gri VHS K Systematics - Mind the Gap!

16 Cosmic shear measurement

Shear is 1% effect, to be measured to 1% to get w to 1% GREAT08 (Bridle et al.); GREAT10 (Kitching et al.); GREAT3 (Mandelbaum & Rowe et al) Photo-z –Spectra cross talk

• Approximately, for a photo-z slice:

-1/2 (δw/ w) = 5 (δz/ z) = 5 (σz/z) Ns

=> the target accuracy in w

and photo-z scaer σz dictate the number of required 5 6 spectroscopic redshis Ns =10 -10

18 DESI – Spectroscopic Survey “10 times BOSS” Mayall telescope available up to 100% of dark time, 5000 fibres, 20min base integration time 20 million targets 18,000 deg2 survey

1 million Ly-A QSOs +2.5 million QSOs DESI

18 million ELGs

4 million LRGs Combining imaging and spectroscopy

Dark Energy (W0, Wa) Mod Grav (Q, R)

2 5 ee FoM = 1.6 ee MGFoM = 0.3 nn MGFoM = 0.6 4 nn FoM = 0.9 1.8 ee + nn FoM = 7.2 ee + nn MGFoM = 50.1 ee + ne + nn FoM = 27.8 ee + ne + nn MGFoM = 112.7 3 1.6

2 1.4

1 1.2 )/2 0 R a

+ 1

w 0 (1 0 −1 Q 0.8

−2 0.6

−3 0.4

−4 0.2

−5 0 −2 −1.5 −1 −0.5 0 −4 −2 0 2 4 6 w Q 0 0 • DES-like WGL + DESI-like LSS (incl. RSDs) • Assumes 5000 sq deg for each survey, • 300 million DES galaxies, 10 million DESI galaxies

Kirk, Lahav, Bridle, Jouvel, Abdalla, Frieman, arXiv:1307.8062 EUCLID (“Whole-Sky CLASH”) ESA Cosmic Vision planned launch 2020

* Weak lensing from space + photo-z from the ground

* 15000 sq deg 1B galaxy images * * 50M spectra (+ground based projects, e.g. PS, DES, LSST,…)

21 CLASH:UCL

OL joined the 2009 proposal (thanks to Tom Broadhurst!)

UCL Post-docs: Ole Host and Stephanie Jouvel Manda Banerji (new participant)

Papers: * Photo-z - Jouvel, Host, OL, & CLASH team (ArXiv:1308.0063, A&A) * LSS foreground in SL - Host (ArXiv: 1110.5331, MNRAS) MACS1206

22 RXJ2248 3125 CLASH galaxies 387 DES matches

CLASH& DES&

Banerji et al. (in prep) 23 3-6 CLASH clusters in the DES 5000 sq deg footprint

RXJ2248 already observed by DES 24

CLASH-DES joint projects • Derive scaling relations fron the the 25 CLASH clusters as input for DES cluster mass function (via conditional probabilities!) • RXJ2248: DES-CLASH-WFI-VHS-… calibration of photometry, photo-z and shapes • LBG Luminosity Function @ z=5: - bright-end from DES - faint-end from CLASH • Other ideas? 25