Cosmology with the ESA Euclid Mission Andrea Cimatti Università di Bologna Dipartimento di Astronomia On behalf of the Euclid Italy Team ESA Cosmic Vision 2015-2025 M-class Mission Candidate Selected in February 2010 2010-2011: Definition phase (mid 2011: M1/M2 selection) 2017-2018 : launch of M1-M2 missions XCVI Congresso Nazionale SIF Bologna 20-24 Settembre 2010
DARK Universe (76% Dark Energy + 20% Dark Matter) Baryons (4%)
Dark Energy Affects cosmic geometry and structure growth Parameterised by equation of state: P/ρ = w w < 1/3 : required to have acceleration Latest best estimate (assuming w=const!): w = 1.03 ± 0.09 (Amanullah et al. 2010) w = -1 : cosmological constant (Einstein s Λ) w > -1 : quintessence (scalar field variable in space and time) w < -1 : exotic physics (e.g. increase with time) Or : Modification of General Relativity? Void model? Other? Komatsu et al. 2009 Requirements for DE experiments w(a)=w 0 +(1-a)w a - 1% precision on w 0 (now 30%) - 10% on w a (now 100%)
w = constant = 1.03 ± 0.09 (Amanullah et al. 2010) Linder 2010
Linder 2010
Weak gravitational lensing Baryonic Acoustic Oscillations Redshift-space distorsions Clusters of galaxies Integrated Sachs-Wolfe effect Type Ia Supernovae Multi-probe approach multi-purpose cosmology mission
Weak Gravitational Lensing mass and shear distribution Map the 3D distribution of Dark Matter in the Universe Measures the mass without assumptions on the relation between mass and light Power spectrum very sensitive to Dark Energy through geometry and growth Need measurements of galaxy shapes and photometric redshifts
Euclid Slitless Spectroscopy For each galaxy: RA, Dec, Redshift 3-D map Boxes at different redshifts: Evolution 70 million star-forming galaxies at 0.5<z<2 in 19 h -3 Gpc 3
CMB (z 1000) Planck Baryonic Acoustic Oscillations (BAO) galaxies (z 1) CMB characteristic scale 150 Mpc galaxies (z 0.6) Constrain H(z) (radial) Constrain D A (z) (tangential) H(z) & D A (z) depend on w(z)
Measuring BAO only 20% of the survey! Preferred distance in galaxy 2-point 3-D correlation function Wiggles in the galaxy large scale distribution power spectrum
Additional Cosmology Probes (for free) Test of Gravity and GR Anisotropy of radial vs tangential clustering Impossible with photometric redshifts! Test of Modified Gravity theories Precision of 2% on the growth exponent γ Break degeneracies for models with same H(z) Full Power Spectrum P(k) Primordial fluctuations and models of inflation Non-Gaussianity Sum of neutrino masses with 0.04 ev accuracy Complementary to CMB Clusters of galaxies Growth of structures and DE SDSS 2SLAQ SDSS LRGs 2dFGRS VVDS Euclid spetroscopy Dark Matter Halos 10 8-10 15 Msun, mass profiles Integrated Sachs-Wolfe effect Type Ia SNe ( 2000-4000 to z 1)
WHY SPECTROSCOPY? Spectroscopic redshifts: σ z = 0.001(1+z) WHY FROM SPACE? IR background: 500x less & stable Stable PSF (WL & spec) Homogeneous data 0.5 < z < 2 with Hα Selection function Unbeatable speed Multi-probe experiment NIR imaging to AB=24 unfeasible from ground on 20,000 deg 2 Complementary with ground Photometric redshifts: σ z = 0.02(1+z)
The Impact of Euclid on Cosmology
VIS NISP Mission elements L2 Orbit 4-5 year mission Telescope: 1.2 m primary diameter Instruments VIS: visible imaging channel: 0.5 deg 2, 0.10 pixels, 0.18 PSF, broad band R+I+Z (0.55-0.92 μm) to AB=24.5, CCD detectors. NISP: 0.5 deg 2, 0.3 pixels, HgCdTe detectors Slitless spectra: 1-2 μm, R=500, F>4x10-16 ergs/cm 2 /s, 0.5<z(Hα)<2 Imaging in Y, J, H bands to AB=24 Euclid Surveys Wide Extragalactic 20,000 deg 2 optical imaging NIR imaging + NIR spectro. Deep ~40 deg 2 Galactic Plane Survey (TBD)
The immense Euclid legacy Unique legacy survey: 2 billion galaxies imaged in optical/nir to mag 24, 70 million NIR galaxy spectra, full extragalactic sky coverage, Galactic sources Unique dataset for various fields in astronomy: galaxy evolution, search for high-z objects, clusters, strong lensing, brown dwarfs, exo-planets, etc Synergies with other facilities: JWST, Planck, erosita, GAIA, DES, Pan- STARSS, LSST, etc All data publicly available through the Euclid Legacy Archive
The Italian Role Joint Euclid Consortium = EIC + ENIS consortia (9 Apr 2010) Italy and France are the major contributors Potential contribution from NASA (from 0% to 33%) 2 Italian members in the Board (A. Cimatti + R. Scaramella) 1 Italian in the ESA Euclid Science Team (A. Cimatti, NISP Scientist) Euclid-Italy Team: ~120 members (financial support from ASI) : Universities : BO, MI, NA, PD, RM La Sapienza, RM Tor Vergata, SISSA, SNS, TS INAF : OABO, OABrera, OACT, OANA, OAPD, OARM, OATO, OATS, IASFBO, IASFMI, IFSI Activities Science (theory & observations) : cosmology, galaxy formation & evolution Instrumentation : electronics, optomechanics, thermal, AIV/AIT Ground Segment : Science Data Centers Italy leads: NISP instrument, Ground Segment, several key science cases (galaxy clustering, galaxy clusters, strong lensing, legacy), plus deputy in other areas Euclid Italy : open to involve new collaborators
PLANCK EUCLID The high precision Dark Energy & Cosmology mission Essential and unbeatable synergy of imaging + spectroscopy Euclid will impact the whole astrophysics and cosmology for decades to come