SKA radio cosmology: Correlation with other data

SKA radio cosmology: Correlation with other data The 2020+ sky and SKA capabilities Carole Jackson Curtin Institute of Radio Astronomy

SKA Cosmology correlation with other data Now & the SKA future (2020+ era) of cosmology Challenges where can SKA1 (2) Be the lead or unique instrument for a (class of) experiments? Provide data as second-level inputs (insights into biases, add significant improvement or support and important corrections etc) to other (marginal) results? (Or perhaps) not in the game.? (by choice or radio-catch up?) Which characteristics/correlation with other data are vital i.e. Which (Radio) cosmol observations are must haves?

BAO science remains a key SKA(2) goal; 1 < z < 2 = ( 470 Footer 700 text MHz) - slideshow imaging title at the req d sensitivity 30.07.2010 levels will only be met by the SKA2 spec (?)

SKA Cosmology Complementary data radio waveband.. Radio 50 MHz 3 (poss up to 20 GHz) (many) SKA cosmology observations could benefit from population differentiation (RGs, Qs, SFs etc) -> provide multiple tracers & overcome cosmic variance limitations: drives req for high confidence cross-waveband correlations SKA cosmology key science should ensure max possible value from other SKA key science (surveys) as well as other wavelength surveys & experiments

Footer text - slideshow title 30.07.2010 M Huynh SPARCs meet

M Huynh SPARCs meet

SKA Key Science: Evolving reqs - other wavebands & experiments Very active field; Key science is (re)setting SKA requirement spec on ~3 year timescale; up against some significant dedicated instruments (to 2020 & beyond ) Balance key observational reqs (as seen now) with flexibility And relevance for long-term future. SKA Cosmology summary (draft?) so far: SKA1 with 2 arcsec resolution some incremental cosmology obs; competitive but not ground breaking? What about HI intensity mapping (Battye, Davis & Weller 2004).. SKA1 with 0.5 arcsec resolution leading science regime = weak lensing

New SKA-era facilities DES (Dark Energy Survey) DECam Blanco 4m telescope commenced Aug 2013; 5 year survey southern sky Pan-STARRS/SKYMAPPER whole sky imaging LSST (10-yr survey commence 2022 (plan)) Wide-field survey teelscope (3.5 dia fov); 8m weak lensing JWST (space, launch 2018) opt/ir

New SKA-era facilities Euclid (1.2m space; launch 2020) 6 year mission opt/ir billion galaxy low-precision z s (photom) & million galaxy high-precision z s to z=2 high precision imaging -> grav lensing galaxy clustering (BAO & z-space distortion) 20,000 sq.deg survey to H=24 spectroscopic survey to H=22 Deep field to H=26 spectroscopy to H=24 WFIRST (successor to JDEM) 2.4m wide field IR survey telescope (space, launch bid for 2020+?)

New SKA-era facilities & improved. TMT/GMT 30-m class telescopes; small FOV (targets) Additional ALMA bands (tbc) Jansky VLA 330 MHz, 74 MHz Other spectros surveys - SDSS3-BOSS/+, VISTA sky surveys.. Wide-field instrs on (4) 8-10m telescopes (BIGBOSS )

Some other key cosmology Experiments posited for 2020+ E-ELT Science case includes Direct detection of redshift drift (about 10cm/s per decade) observable from stable spectros of distant QSOs Variation in Fundamental Constants (Δα/α) fn(z)) Non-EM; Grav wave detectors (SKA role to do fast-followup of cosmolg important events strings/bhs )

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ISW required overlap of SKA with other data SKA + Euclid are the primary data Require high resolution deep survey(s) (current SKA spec un-degraded) Need confident correlation CMB & radio surveys; excellent (SKA) stability PSF, calibration

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BAO other options & correlation with other data SKA1; Intensity mapping; HI associated with LSS SKA low angular resolution survey(s) correlate with other data; ASKAP/Optical zgrs (Battye, Davis & Weller, MNRAS 2004) Must be able to subtract foregrounds to better than 0.1% Needs high degree of polarisation purity (minimum leakage Into I: ) Other BAO: Optical Ly a correlations? Footer text - slideshow title 30.07.2010

Scale of SKA2 >> larger; are there SKA1 design considerations for cosomology? wide field surveys/resolution & sensitivity Footer text - slideshow title 30.07.2010