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 +
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 ● 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 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 Euclid+ground: photo-z of 1.5 billion lensed galaxies Euclid Requirements: • photo-z for ~all WL N galaxies I R d a • cover the whole Euclid t a 2 f sky (15000 deg ) r o m • E accuracy = 0.05x(1+z) u c l i d 4 optical bands needed N I R i m a g Courtesy Euclid SWG Photo-z and OU-PHZ e s . Visible data obtained from ground based telescopes Euclid IAU General Assembly Hawaii, August 2015 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 Massive galaxies Few hundreds Few tenss (1 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 galaxyscale lenses (0.7 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 → Very highz QSOs Quasars at z > 8 ~30 None Euclid IAU General Assembly Hawaii, August 2015 Clusters of galaxies Euclid data will give “for free”: • ~200,000 clusters between 0.2 Sartoris et al. 2015 → deviations from standard DE and GR models → dark matter density profiles on scales >100 kpc Synergy with Planck and eROSITA Euclid IAU General Assembly Hawaii, August 2015 Euclid Post-Planck Forecast for the Primary Program Assume systematic errors are under control Ref: Euclid RB Modified Dark Matter Initial Conditions Dark Energy arXiv:1110.3193 Gravity Parameter m /eV fNL wp wa FoM = 1/(Δw0×Δwa) Euclid primary 0.010 0.027 5.5 0.015 0.150 430 (WL+GC) EuclidAll 0.009 0.020 2.0 0.013 0.048 1540 (clusters,ISW) Euclid+Planck 0.007 0.019 2.0 0.007 0.035 6000 Improvement 30 >10 >40 >400 Factor From Euclid data alone if data consistent with , and FoM > 400 → favoured with odds of more than 100:1 = a “decisive” statistical evidence. Euclid IAU General Assembly Hawaii, August 2015 Summary: the post-Planck cosmology mission • Euclid will Explore the dark universe: DE, DM (in particular neutrinos), MG – Use 5 cosmological probes, with at least 2 independent – Get the percent precision on P(k), w and the growth factor – A revolution for wide field VIS and NIR surveys • Euclid Legacy = 12 billion sources, >30 million redshifts; – A mine of images and spectra for the community for years; – A reservoir of targets for SUBARU, JWST, E-ELT, TMT, ALMA, VLT – A set of astronomical catalogues useful until 2040+ – A synergy with wide field panchromatic all sky surveys: Planck, GAIA, LSST, WFIRST, e-ROSITA, SKA Euclid IAU General Assembly Hawaii, August 2015 Thank you Euclid IAU General Assembly Hawaii, August 2015 The ESA Euclid space mission in a nutshell PLM+SVM: 2010-2019 VIS imaging: 2010- Airbus/DS - ESA La mission Euclid de l’ESA: objectifs2020 Soyuz@Kourou (VIS team) Q1 2020 scientifiques? NIR spectro-imaging 2010-2020 (NISP team) Surveys: 2010-2028 (Survey WG) SGS: 2010-2028 6 yrs - 15,000 deg2 SWG: Ground data • Commisionning – SV 2019-2028 • Euclid opération: 5.5 yrs:Euclid Wide+Deep • +: SNIa, mu-lens, MW? ~100 PB data processing (EC-SGS team) – Science analyses A sharp view of the cosmos Simulation of M51 with VIS NearHST resolution images across the sky will revolutionise several areas of galaxy evolution Courtesy J. Brinchmann, S. Warren 1000 times more area with high resolution imaging = 3 orders of magnitude increase in sample size (galaxygalaxy lenses, galaxy mergers) Euclid will be 3 magnitudes deeper → Euclid Legacy = SuperSloan Survey Euclid IAU General Assembly Hawaii, August 2015 SLACS (~2010 - HST) Galaxy-scale strong lensing with Euclid Euclid Legacy : after 2 months (66 months planned) SLACS