Cosmological surveys: from Planck to Euclid Nabila Aghanim Institut d'Astrophysique Spatiale On behalf of the Euclid Consortium Euclid IAU General Assembly Hawaii, August 2015 The dark universe after Planck Planck collaboration. 2014 A post-Planck concordance cosmology with two puzzling ingredients: dark matter & dark energy → acceleration of expansion • Dark Energy: new component opposing gravitation on cosmological scales, as a negative pressure? • Modified Gravity: Einstein’s GR is not a good description of gravitation on cosmic scales? Parameterising our ignorance: DE equation of state: P/=w and w(a)=wp + wa(ap-a) Growth rate of structure formation: f ~ 0.55 =GR After Planck: w may be -1, may vary with time … (cf talk by Pettorino) Planck cannot probe its nature/effects in detail → different cosmological probes: Expansion rate (BAO, Galaxy clustering) Distances (SN, BAO) Growth rate (Weak Lensing, clusters, iSW) Euclid IAU General Assembly Hawaii, August 2015 Primary Objectives of Euclid ESA mission: the Dark Universe • Understand the origin of the accelerating expansion • Probe the properties and nature of Dark Energy and Gravity • Distinguish effects of and dynamical DE: Measure w(a) → slices in redshift ● Probe the growth of structures and distinguish effects of GR from MG models → slices in redshift • Separately constrain the metrics potentials () as function of scale and time • Probe effects of Dark Energy, Dark Matter and Gravity by: • Using at least 2 independent but complementary probes : WL, GC (5 probes in total) – Tracking their observational signatures on the Geometry of the universe and Cosmic history of structure formation • Controling systematic residuals to an unprecedented level of accuracy Euclid IAU General Assembly Hawaii, August 2015 Requirements to design the mission Wide survey Deep survey • WL and systematics Survey: 6 years size 15, 000 deg 2 40 deg2 N/S 2 VIS imaging +<c > Depth n > 30/arcmin2 M = 26.5 gal AB ● Small PSF, Knowledge of the PSF size MAB =24.5, 10σ for gal size ● 0.3 » Knowledge of distortion <z> ~0.9 ● Stability in time → space telescope 2 2 -3 PSF size knowledge σ[R ]/R <10 ● Photo-z accurary: 0.05x(1+z) ; Catastrophic z < 10% Multiplicative σ[m]<2 .10-3 bias in shape Additive bias in σ[c]<2 .10-4 shape Ellipticity RMS σ[e]<2 . 10-4 GC and systematics NIP photometry: YJH Depth 24 M 26 M AB AB • Correct for contaminated spectra ; confusion ... NIS spectroscopy: 4 R exp., 3 R orientations Flux limit 2 10-16 5 10-17 • Understand selection →Deep field (erg/cm2/s) (photo+spectro) Completness > 45 % >99% • Completeness Purity >80% >99% Confusion 3 rotations >12 rotations • Purity Euclid IAU General Assembly Hawaii, August 2015 Euclid PLM and scientific instruments From Thales Alenia Italy, Airbus DS, ESA Project office and Euclid Consortium Launch Q1 2020 (Soyuz@Kourou) vis Field stop NISP detectors Common VIS and NIR FoV = 0.54 deg2 NISP radiators VIS Survey in 6 years →15,000 deg2 NISP NISP Telemetry: 240 Gbt/day 16 2kx2K H2GR detectors 0.3 arcsec pixel on sky (Wide survey only with R-grism) Limiting mag AB for wide survey of magAB 24 (5 ) NIR photometry 3 Filters: Y, J, H Courtesy J. Amiaux & survey WG NIR slitless spectroscopy 4 grisms (1100 – 2000nm), 3×10-16ergcm-2s-1 3.5σ line flux Euclid IAU General Assembly Hawaii, August 2015 Galaxy Clustering: BAO + RSD Euclid: Over 15,000 deg2 30 million spectroscopic redshifts with 0.001 (1+z) accuracy up to z~2 High precision 3D position distribution of galaxies with spectro-z over 0.7<z<1.8 ● Measure of BAO in galaxy power spectrum (standard ruler)probes expansion rate and of anisotropy of the correlation function (RSD) clustering history induced by BAO RSD gravity; H(z) Euclid IAU General Assembly Hawaii, August 2015 Galaxy clustering Anderson et al. 2012 Distance-redshift relation moves P(k) Courtesy W. Percival Euclid forecast (one redshift bin 0.2) SDSS today 0.9 < z < 1.1 BOSS-CMASS galaxies z~0.57 Total effective volume Total effective volume 3 Veff = 57.4 Gpc 3 Veff = 2.2 Gpc Dark matter power spectrum recovered to 1% Euclid IAU General Assembly Hawaii, August 2015 RSD from Euclid redshift survey Expansion and growth from galaxy clustering RSD as a measure of the growth rate of structure Euclid Euclid forecast (Majerotto et al. 2012) Successful combination of CMB & BAO demonstrated in the Planck analyses discussed in details (cf talk by Freedman) Euclid IAU General Assembly Hawaii, August 2015 Cosmology with the Euclid Redshift Survey ns What is the expansion rate of the tio Universe? illa sc O Understanding tic us Dark Energy o fect Ac i ef n nsk What is the expansion rate of the o czy ry -Pa Universe? Ba ck Alco istortions Redshift-Space D Understanding How does structure form within this energy-density, background? Galaxy gravity Survey Com ovin g c lust erin L g ar What are the neutrino ge -s masses, matter density? Understanding ca le energy-density s ha IS pe W e f fe What is f , I.e. non-Gaussianity? c nl t Understanding GR-horizon effects Inflation, GR Does the potential change along line- Understanding of-sight to CMB DE, GR Euclid IAU General Assembly Hawaii, August 2015 The long way from raw spectra to data NISP spectroscopy (2015 simulations) Courtesy P. Franzetti, B. Garilli, A. Ealet et al. Need to understand confusion, mis- Slitless spectroscopy: Uniform identification, zero-point errors, etc. sample but contaminated spectra Need to understand the populations →simulations and deep survey are (radial & angular completeness; radial & crucial to control systematics angular density variations, etc) Euclid IAU General Assembly Hawaii, August 2015 Weak Lensing tomography and 3D lensing Euclid: Colombi, Mellier 2001 Over 15,000 deg2 WL measurement with 1.5 x109 galaxies to slice the universe and control contamination by intrinsic alignments Cosmic shear over 0<z<2 Source plane z2 Source plane z1 • Probes distribution of matter (Dark +Luminous): expansion history, growth rate of structure formation. Shapes+distance of galaxies: shear amplitude in redshift slices. “Photometric redshifts” sufficient for distances: optical+NIR data. Euclid IAU General Assembly Hawaii, August 2015 NIR data from Euclid NIR images. Euclid Euclid August Assembly2015 Hawaii, IAU General Visible data obtainedVisible from ground based telescopes ) 2 4 optical bands needed bands optical 4 accuracy = accuracy 0.05x(1+z) cover the whole Euclid Euclid the whole cover photo-z for ~all WL WL for ~all photo-z Euclid+ground: photo-z of 1.5 billion lensed galaxies Courtesy Euclid SWG Photo-z and OU-PHZ • sky (15000 deg sky (15000 • galaxies galaxies • Requirements: Euclid Weak Lensing Dark matter power spectrum Input P(k) Tomographic WL shear cross-power spectrum for bins 0.5 < z < 1.0 and 1.0 < z < 1.5 Dark matter power spectrum recovered to 1% B-modes Euclid IAU General Assembly Hawaii, August 2015 Forecast for combined CMB & galaxy lensing Planck collaboration 2014 Linear & non-linear scales CMB & galaxy lensing combination improves: Dark energy, galaxy alignment measurements and neutrino mass Euclid IAU General Assembly Hawaii, August 2015 Constraints on w: Updates (post-Planck) on Euclid Red Book (VIS+NISP) Planck + Current BAO MCMC Chains Planck + BAO + Euclid WL w0 Planck + BAO + Euclid WL + Euclid BAO w a FoM Planck ≈ 6 FoM Planck+Euclid ≈ 6000 h σ8 ΩB n ΩDE Ω w w M 0 a h σ8 ΩB n ΩDE Courtesy T. Kitching & Euclid Forecast IST Euclid IAU General Assembly Hawaii, August 2015 Cosmology with the Euclid Weak Lensing survey Colombi, Mellier 2001 y ph ra og What is the expansion rate of the om Universe? , t m ru Understanding ct pe c Dark Energy r s un e ss F ow Ma What is the expansion rate of the p rs M ste Universe? D Clu at, k st Pea um, tomogr M power spectr Understanding D How does structure form within this energy-density, background? WL gravity D Survey M p owe r sp ect 3 rum -p t s What are the neutrino ta Understanding tis masses, matter density? ti cs energy-density , H al os iS What is f , which quantifies non- W nl Understanding e Gaussianity? f fe Inflation, GR c t GR-horizon effects Does the potential change along line- Understanding of-sight to CMB DE, GR Euclid IAU General Assembly Hawaii, August 2015 VIS performance: imaging Courtesy M. Cropper, S. Niemi A 4kx4k view of the Euclid sky Cuts made to highlight artefacts due to Charge Transfer Inefficiency Tested in worse case Can be corrected to required accuracy with no impact on P(k) and cosmology core progr. Euclid IAU General Assembly Hawaii, August 2015 Euclid VIS+NISP Legacy Very large samples of sources Before → Diversity of populations Objects Euclid Euclid Exquisite imaging of galaxies → Morphologies, mergers Galaxies at 1<z<3 with precise mass ~2x108 ~5x106 measurement Massive galaxies Few hundreds Few tenss (1<z<3)) Hα Emitters with metal abundance ~4x107/104 ~104/~102 ? M51 @VIS Courtesy J. Brinchmann, S. Warren measurements at z~2- 3 Strong and Weak Lensing Galaxies in clusters ~2x104 ~103 ? → Galaxy evolution as function DM halo of galaxies at z>1 → Galaxy alignement Active Galactic → 5000 clusters with giant arcs, strong Nuclei galaxies ~104 <103 galaxy-scale lenses (0.7<z<2) Huge volumes and numbers Dwarf galaxies ~105 2 → Rare/extreme sources Teff ~400K Y dwarfs ~few 10 <10 Lensing galaxies with NIR Spectroscopy ~300,000 ~10-100 arc and rings → Metals, star formation@ z>1 Quasars at z > 8 ~30 None → Very high-z QSOs Euclid IAU General Assembly Hawaii, August 2015 Clusters of galaxies Euclid data will give ªfor freeº: • ~200,000 clusters between 0.2<z<2 , ~40,000 at z>1 • ~ 5000 giant gravitational arcs ( SL+WL mass) → very accurate masses for the whole sample of clusters (WL) Sartoris et al.