SKA-Euclid Synergy: a summary

Transcription

1 SKA-Euclid Synergy: a summary Françoise Combes Observatoire de Paris 18 September 2013

2 What do we want to know? Composition of the Universe More than 95% unknown Dark energy: Is it varying with time? All data up to now lead to a Cosmological constant scenario P= w ρ w = w0 + wa (1-a) w0 = -1, wa=0 Could it be so boring? New physics? 2

3 Main issues to address, SKA & Euclid Cosmology: Dark Energy, w0, wa Dark Matter: neutrino mass mν New Physics, modified gravity Growth rate γ Inflation, non-gaussianity: fnl, ns, σ8 Methods BAO and Weak lensing + Galaxy Clustering RSD, growth rate, ISW In addition H0 can be measured from masers with SKA Reionization, first galaxies: only SKA 3

4 Galaxy formation and evolution Aside science for Euclid (however SDSS pub 83% Legacy, 11% Cosmology, Jarle Brinchman) One of the main drivers for SKA Euclid will bring 12 billion sources, 50 million redshifts SKA: 1 billion HI redshifts Targets for JWST, E-ELT, ALMA, etc.. Fundamental Physics, Pulsars Another driver for SKA1 Strong gravity, gravitational waves, new physics 4

5 SH History & Galaxy quenching How to obtain the molecular gas? Only on sub-samples with ALMA SFR could be traced by RC? FIRC correlation, to be understood Matt Jarvis, Dan Smith 5

6 Already some results Tension from Planck determined Ho=67.3 and Ho=73.8 (Riess et al 2011), Supernovae and other good Calibrators (Cepheids, Masers, SZ..) BAO determined at low z, and begins at high z.. Lensing: galaxies and also CMB Some tension SNLS: DE compatible with Cosmological cst w=-1, wa=0 Planck w= Jo Dunkley 6

7 Cluster number with Planck-SZ Nabila Aghanim Tension between σ8 CMB and SZ clusters Possible bias? Massive neutrino? Large number of low-z clusters Followed up with XMM Unrelaxed clusters With radio halos 7

8 Other constraints/tensions Cluster-Subcluster: 1E tension with ΛCDM - kill quintessence, favorize phantom model Vincent Bouillot Dwarf galaxies in the local volume Dark matter cores, in great tension with LCDM Euclid + SKA (gas) will clarify the topic Ivan Baldry 8

9 The SKA phase 1 JVLA Meerkat SKA1-mid ASKAP SKA1-sur LOFAR SKA1-low Sensitivity 6 xjvla 6xASKAP 16xLOFAR Survey Speed Phil Diamond 9

10 New technology, new problems LOFAR: Huub Rottgering RFI ionospheric seeing, sidelobes of strong sources, calibrations, etc.. Low frequency: EMBRACE Beamforming, Steve Torchinski 10

11 Euclid key figures Wide survey deg2, BAO, RSD 50 millions galaxies with z (NIR spectro slitless) WL: 1.5 billion with shapes, 10 slices Deep survey: 40 deg2, 2mag deeper Galaxy clusters, growth rate Yannick Mellier 11

12 Ground spectroscopy in synergy MOONS is ideal to provide the control sample for Euclid Euclid is ideal to provide deep near-ir photometry for MOONS In addition to the ground photo-z Survey, with CFHT in the North DES, LSST in the South Michele Cirasuolo Isobel Hook E-ELT: very small FOV Will make follow-up of SKA and Euclid sources, with high resolution Complementary in science goals 12

13 Data management A huge challenge, for SKA Petaflops machines working continuoulsy Exabytes per hour? 10x global internet! LSST: more than half of the cost! Machine learning software Euclid: 100Gbytes /day Sparsity, Compressive sensing Jason McEwen 13

14 Cross correlation of catalogs A lot of work needed, to exploit the synergy Likelyhood ratio Kim McAlpine + Reliabilitty, simulation of EMU/WODAN AGN identification, Optical/Radio Tests on VLA/COSMOS Sandro Bardelli 14

15 Overlap in space, redshift SKA-Euclid projects: (mainly <z>=1-2) Euclid + SKA photometry + emission line galaxy analyses, Euclid + SKA redshifts, Euclid + SKA morphometry and astrometry Zmedian~1 15

16 Euclid: Time-scales : construction of SKA1 2019/20: early science begins : construction of SKA2 SKA operational for 50 years. LSST: Commissioning: Science! E-ELT:

17 Synergies Main point: different systematics Weak lensing Γobs = Γ +Γint+Γsys When correlating Radio and Optical Γsys * Γsys small David Bacon, Michael Brown Same principle as crossing different methods: WL and BAO Much less systematics Tony Tyson 17

18 Polarisation to disentangle intrinsic orientation Polarisation should keep information on the intrinsic elongation Suppress intrinsic alignment term Can help to beat the systematics? Michael Brown 3D (velocity) Direct Shear Measurement Rachel Webster Use the velocity field. Flexion due to shear, will make the axis non perpendicular Caveats: bars and warps? 18

19 Redshift Space distortions Finger of god, corresponding to a cluster In the optical, but not in the HI! Martin Meyer Luigi Guzzo Beutler et al

20 Comparable galaxy numbers Filipe Abdalla Different biases: HI surveys are not cluster biased SKA: no bias from dust, stars.. Larger area covered in the sky (but less spatial resolution) 20

21 Simulations Carlton Baugh BAO from Millenium XXL, large enough volume Mass function of atomic hydrogen Confrontation with observations Tests of cosmology More understanding of galaxy evolution 21

22 Simulations of EoR Only simulations for now! Synergy Euclid /SKA Discovery of the QSO in the epoch of reionisation Detection of the HII region around the QSO, at high redshift Garelt Mellema 22

23 A new dimension: the transient sky 4 FRB found, 5 FRB per day expected with SKA2 Bob Braun LSST millions of alerts/day PopIII SN? A. Meiksin Fender & Bell

24 Strong Lensing Leon Koopmans 24

25 Will become an industry Substructure study; high-z normal galaxies 25

26 Unconventional models Inhomogeneous Dark Energy Claudio Gomez Dark stars: Heating by dark matter Annihilation at high redshift DRAGONS Katie Mack 26

27 Tests of the law of gravity Ultra-large scales Mario Santos GR corrections, non-gaussianities GR of f(r), DGP, TeVes theories? Difficult, degeneracies, growth factor, LSS Cross correlation of lensing, clustering, SKA+Euclid Stefano Camera Growth of perturbations in parametrized gravity Plug-and-play formula, general for all models Growth rate not the only nor best parameer Tessa Baker 27

28 The main puzzles of cosmology and galaxy formation are on the point to be solved We live exciting times! 28