RADIO-OPTICAL-cmb SYNERGIES Alkistis Pourtsidou ICG Portsmouth Image credit: Hayden Planetarium, 2014
New Frontiers in Observational Cosmology [Planck 2015] 95% of our Universe is very strange - new physics! Use large sky surveys, multiple wavelengths, and multiple probes Invest in pathfinders Exploit synergies Planck Euclid SKA
Series of radio telescopes, very sensitive to a wide range of frequencies (redshifts) SKA Phase 1: 2020+ MeerKAT pathfinder live now! THE SQUARE KILOMETRE ARRAY (SKA) MeerKAT/SKA-Mid will complement and compete with optical galaxy surveys (0<z<3) SKA-Low will explore the unknown! (3<z<25)
Testing General Relativity (Strong Regime, Gravitational Waves) Cradle of Life (Planets, Molecules, SETI) Magnetism (Origin, Evolution) Cosmic Dawn and EoR (First Stars and Galaxies) Galaxy Evolution (HI, Continuum) Cosmology (Dark Energy, Large Scale Structure) Exploration of the Unknown Credit: SKA Office
euclid & ska synergies [SKA Science Book 2015] Euclid & SKA Synergies Thomas D. Kitching 1,DavidBacon 2,MichaelL.Brown 3,PhilipBull 4,JasonD. McEwen 1,MasamuneOguri 5,RobertoScaramella 6,KeitaroTakahashi 7,Kinwah Wu 1,DaisukeYamauchi 8
euclid & ska synergies SKA Phase 1 and Euclid will be commissioned on similar timescales Multitude of cross-correlations statistics Same sky, complementary overlapping depths galaxy clustering (BAO and RSDs) weak lensing Euclid & SKA Synergies E Thomas D. Kitching 1,DavidBacon 2,MichaelL.Brown 3,PhilipBull 4,JasonD. McEwen 1,MasamuneOguri 5,RobertoScaramella 6,KeitaroTakahashi 7,Kinwah Wu 1,DaisukeYamauchi 8 S 21cm intensity mapping and Planck (CMB, SZ, ISW) Cross-correlations great for mitigating systematic effects! Also: Simulations synergies
RADIO precision COSMOLOGY: THE INTENSITY MAPPING METHOD [Battye et al 2004, Chang et al 2008, Peterson et al 2009, Seo et al 2010, ] galaxies IM map Detecting HI (neutral hydrogen) galaxies via their 21cm emission line is very expensive But cosmological information is on large scales Get intensity map of the HI 21cm emission line - like CMB but 3D! [Image credit: Steve Cunnington] Excellent redshift resolution So, what s the catch? Signal of the order 0.1 mk foregrounds much bigger 21cm IM surveys: GBT, BINGO, CHIME, HIRAX, MeerKLASS, SKA!
HI EVOLUTION HI evolution is currently quite poorly constrained We need to know HI,b HI Important for astrophysics and cosmology alike! P HI / 2 HIb 2 HIP m Use IM survey with MeerKAT/SKA1-Mid to constrain them! [c.f. Crighton et al 2015]
An IM SURVEY USING MEERKAT/SKA1-MID [PI: Mario Santos]! [Euclideans involved: David Bacon, Stefano Camera, AP, Roy Maartens] MeerKAT: 64 13.5 m dishes Perform an IM survey, 4000 sq. deg. and 5 months observation time [AP et al 2016] Large improvement on current constraints using MeerKAT IM GBT Also: BAOs, RSDs, f NL, multi-tracers [Bull et al, Camera et al, Fonseca et al, AP et al, Santos et al ]
ska-euclid cross-correlations: HI evolution P HI,g / HI b HI b g rp m DES Detected by GBT x WiggleZ Euclid
ska-euclid cross-correlations: HI evolution P HI,g / HI b HI b g rp m DES Detected at z = 0.8 by GBT x WiggleZ SKA1-Mid x Euclid HI b HI r Euclid 5000 deg 2 / 5000 hrs
ska-euclid cross-correlations: DARK ENERGY linear growth DES angular diameter distance Hubble rate Euclid More x-corr: e.g. MeerKAT x DES, SKA x LSST, HIRAX x Euclid/LSST, CHIME x DESI!
less IS MORE Less systematics to worry about: the cosmic shear case [Camera, Harrison, Bonaldi & Brown 2016] [SC, Harrison, Bonaldi & Brown, 2016] DES wa Euclid Full SKA Euclid Full SKA Euclid w 0 w 0
MULTIPLE TRACERS Multi-tracers technique for large scales - beat cosmic variance! Needs tracers with different biases [Seljak; Seljak & McDonald 2009] DES Radio IM and optical combination could be ideal! Photo-gal MT1-low z MT2-high z [Fonseca, Santos, Maartens 2017] Euclid
photo-z calibration Calibrate photometric redshifts with intensity mapping observations [Alonso, Ferreira, Jarvis, Moodley 2017] DES Euclid
radio-optical-cmb:combined data and synergies Plenty of science cases: Combine data for DE constraints, nongaussianities, neutrino masses, ISW detection, SZ effect, unbiased gravity tests (e.g. EG), primordial magnetic fields, calibrating systematics, Testing inflation with CMB and IM: spectral runnings [AP arxiv:1612.05138] P(k) (n s, s, s) Planck COrE + COrE SKA1-Mid SKA2-Mid HIRAX galaxies k NL P s (k) =A s k k? ns 1+ 1 2 sln(k/k? )+ 1 6 s ln 2 (k/k? ) k Surveys SKA2-Low
Special thanks to Dida Markovič for being my Euclid guru :-)