WFIRST & Euclid Jason Rhodes NASA Jet Propulsion Laboratory California Institute of Technology Copyright 2011 California Institute of Technology. Government sponsorship acknowledged.Overview Fundamental Scientific Questions • Dark Matter and Energy • The abundance of Earth-like planets • The Evolution of Galaxies & Near Infrared Survey Science The Missions: • Euclid- ESA Cosmic Visions • Wide Field Infrared Survey Telescope - NASADark Energy 73% 23% Dark Matter H, He Gas 4% Stars 0.4% Neutrinos 0.3% The Components of the Universe All of chemistry, biology, physics…The Next Piece of the Pie What is that stuff???? One of the most compelling and important questions in science!The Universe is Expanding Distance Velocity Hubble, 1929 Hubble Space Telescope The farther away something is, the faster it is moving away, in all directions!The Expansion is Accelerating! Perlmutter & Schmidt, 2003 Universe with just mass Universe with something (dark energy) making the expansion accelerate “recently”Einstein’s Equation Gravity or space curvature Mass and energy Cosmological constant or Dark Energy (but maybe not actually a constant) We could also be “wrong” about the left hand side (gravity). We will test this as we attempt to measure dark energy. • Λ term on right hand side introduced to allow for a ‘steady state’ Universe • Don’t need it if the Universe is expanding but deceleratingEinstein’s Blunder (?) • Einstein added the cosmological constant Λ so his equations would work for a static universe • Before Hubble, it was assumed that the universe was static- that was aesthetically pleasing • When the expansion of the Universe was discovered, the equations held without Λ • Einstein called Λ his ‘biggest blunder’ In 1998, when the accelerating expansion was discovered, Λ was reintroduced! Einstein’s ‘biggest blunder’ is going to win somebody a Nobel Prize!Two Effects Dark Energy affects the: • Expansion history of the Universe • How fast did the Universe expand? • Also called the geometry of the Universe • Growth of structures • How do the dark matter structures (like the ones we recently measured with Hubble) evolve and grow over time • Attractive gravity competes with repulsive dark energy If Einstein’s General Relativity is wrong, modified gravity theories could explain the accelerating expansion. This would change the above effects differently, so we must measure them both!Universes with Dark Energy and -1 < w < -1/3 : • eternal expansion • other galaxies eventually disappear beyond the horizon • gravitationally bound objects stay bound Universes with Dark Energy and w < -1 : • DE density becomes infinite • bound objects torn asunder! • even atoms broken apart! • the “Big Rip” !! • if w = -1.5, Big Rip happens in 22 billion years. Future of the UniverseThree Primary Dark Energy Probes Weak lensing can measure the expansion history and the growth of structure simultaneously Supernova Ia are standard candles that measure the expansion history Baryon Acoustic Oscillations make use of the clustering scale of galaxies as a standard ruler to measure the expansion history CMB Clustering of GalaxiesAre We Alone? The search for planets is fundamental to the search for alien life Multiple techniques exist for finding planets Gravitational microlensing allows a statistical census for planets near the “interesting” region: We want to find Earth- like planets in the habitable zoneNIR Survey ScienceHigh Redshift QuasarsHigh Redshift Quasars • WFIRST or Euclid will identify quasars at z>6 in unprecedented numbers • Science afforded by high-redshift quasars (QSOs): • probe the epoch of reionization in several ways: - luminous background probes for studying intervening universe - Lyα profiles probe state of local gas (e.g., Strömgren sphere radii) - QSO luminosity function (QLF) gives contribution to ionizing budget - radio-loud QSOs provide additional 21 cm probe of reionization • early history of black hole growth • proxy for early galaxy growth / growth of large-scale structure (LSS) • large numbers of high-redshift QSO pairs • brightest (e.g., tip of the luminosity function + lensed) galaxies will likely be selected by the same color criteria. Such sources buy significant additional science, such as early IMF, metallicities, ages of first galaxies (c.f., substantial panchromatic literature on cB58, a strongly lensed z~3 LBG)Normal Galaxies • new near infrared surveys will detect vast numbers of normal galaxies • near-IR data buys improved photometric redshifts: necessary for weak lensing cosmology program, but also essential for studying galaxy evolution • though WFIRST resolution < HST resolution, still expect to resolve most (~80%) of sources brighter than H ~ 25 • grism/spectroscopy data data too... • depth slightly lower than COSMOS, but covering >1000x greater area • near-IR very powerful for identifying massive galaxies at z>1 • very powerful tool for studying high z galaxy clusters:The MissionsEuclid Mapping the geometry of the Dark Universe 2004: Dark Universe Mission proposed as a Theme to ESA’s Cosmic Vision programme Oct 2007: DUNE and SPACE jointly selected for an ESA Assessment Phase 2010-2011: Definition phase April 2010: Formation of single Euclid Consortium December 2010: NASA Call for 2 US Euclid Science Teams July 2011: Final Euclid Proposal- Red Book Oct 2011: Cosmic Vision Selection 2012-2017: Implementation phase 2017-2018: launchEuclid concept • High-precision survey mission to map the geometry of the Dark Universe!• Optimized for two complementary cosmological probes:!— Weak Gravitational Lensing!— Baryonic Acoustic Oscillations!Additional probes: clusters, redshift space distortions, ISW!• Full extragalactic sky survey with 1.2m telescope at L2:!— Imaging: !• High precision imaging at visible wavelengths!• Photometry/Imaging in the near-infrared!— Near Infrared Spectroscopy!• Synergy with ground based surveys!• Legacy science for a wide range of areas in astronomy!• Survey Data public after one year!Euclid goals Understand the nature of Dark Energy and Dark Matter by: • Measuring the DE equation of state parameters w0 and wa to a