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Public surveys with VISTA

Public surveys with VISTA. Will Sutherland (QMUL) VISTA Project Scientist. ESO Paranal Observatory, Chile. VISTA main parameters:. Telescope is “front-end to VIRCAM”. Primary mirror 4.1 m , f/1.0 1.24 m secondary, f/3.25 Cassegrain focus.

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Public surveys with VISTA

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  1. Public surveys with VISTA Will Sutherland (QMUL) VISTA Project Scientist

  2. ESO Paranal Observatory, Chile

  3. VISTA main parameters: • Telescope is “front-end to VIRCAM”. • Primary mirror 4.1 m , f/1.0 • 1.24 m secondary, f/3.25 Cassegrain focus. • Single instrument : VIRCAM (2.9 tonnes, 700 kg cold). • Field corrector, active optics and guiding sensors included in VIRCAM. • 16 Raytheon 2k x 2k near-IR detectors. • Only current instrument with > 4 such detectors. • FoV 1.65 deg diameter, sparse-filled, 0.6 deg2 on-pixels. • Mean pixel scale = 0.339 arcsec. • 7 filters, broadband Z, Y, J, H, Ks, two narrowbands. • ESO facility since Dec 09 (part of UK entry contribution) • > 75% of time for large-scale public surveys.

  4. IR camera field sizes:

  5. VISTA + IR Camera schematic

  6. Primary mirror – first coating, Apr 2008.

  7. IR Camera cross-section

  8. IR focal plane: • 16 arrays, 67 Mpix = 0.60 deg2 = 2150 arcmin2 on-pixels , 0.34 arcsec/pixel. • - 6 offset `pawprints’ gives 1.5 x 1.0 deg2 `tile' , every star covered by  2 pawprints.

  9. Six VISTA Public Surveys: sky coverage (schematic)

  10. Sky coverage (to Jul 2011)

  11. VHS: VISTA Hemisphere Survey(PI: McMahon) • Whole Southern hemisphere. ~ 3.5 mag deeper than 2MASS. • 3 sub-areas with slightly different strategies: • DES area: 120 sec, J, H, Ks. (Y will come from DES). • VST-ATLAS area: 60 sec Y, J, H, Ks. • Rest of hemisphere : 60 sec J, Ks only. • Depth complementary to Skymapper, WISE. • High-z quasars, cool brown dwarfs, ULIRGs; • The near-IR complement to GAIA … sort out reddening/metallicity degeneracy etc.

  12. Wide surveys: point source sensitivity VHS

  13. VVV: VISTA Variables in Via Lactea520 deg2, multi-epoch.(PIs: Minitti, Lucas) • 5 bands to near confusion limit; ~ 100 epochs shallower Ks. • Science goals: • Multi-epoch: RR Lyrae • New globulars • Sgr dwarf • Microlensing • Complement Spitzer, WISE.

  14. VVV [VISTA Variables in the Via Lactea] • Total ~ 1 billion sources, ~ 1 million variables. • RR Lyrae (>50% of total), type II Cepheids • Find variables in known star clusters (obtain distances, reddenings, metallicities) • Eclipsing binaries • Rare variable sources • Microlensing in inner bulge • Look for variable stars in Sag. dwarf • Search for new globulars and open clusters • Search for high proper motion objects and background QSOs

  15. 92 new open cluster candidates, (Borissova et al 2011)

  16. VMC: VISTA Magellanic Clouds survey(PI: Cioni) Entire LMC, SMC, stream. Y, J, Ks; 10σ at Ks ~ 20.4 Goals: structure, star formation history, stellar populations. Some multi-epoch (mean mags for RRLs, periods for AGBs).

  17. VMC (Vista Magellanic Survey) • Resolved stellar populations • Old populations + active star formation + ongoing merging + nearby= ideal laboratory. • Globally resolved history of star formation with unprecedented accuracy • Trace past interactions • Complements optical (VST) and kinematic studies of Magellanic system

  18. VMC colour-mag diagrams(Cioni et al, A+A 2011)

  19. VIKING : VISTA Kilo-degree Infrared Galaxy survey(PI: Sutherland) • 1500 deg2 , high |b|, in two stripes, NGP + SGP. • Area matches 2dFGRS and VST-KIDS. • Optimal areas for Chilean followup: VLT, ALMA, etc. • NGP stripe on equator, overlaps UKIDSS, Sloan, GAMA. • 9-band combined survey: ugri (VST), ZYJHKs (VISTA) • Depth: ~ UKIDSS + 1.5 mag, Sloan + 2 mag. • Science goals: photo-z’s , weak lensing, LSS, high-z quasars, galactic structure, etc. • 400 deg2 common with Herschel ATLAS survey.

  20. VIKING: Exposure times + depths. ~ 400 sec per near-IR filter. J split into 2 x 200 sec. 2 visits per tile: Z,Y, J1 (non-bright); J2,H,Ks (any Moon)

  21. VIKING Science drivers – I z> 6.5 quasars, ultracool brown dwarfs: colour selection in Z, Y, J :

  22. 45 VIKING Quasar candidates – NTT i, z followup. (Bram Venemans + Joe Findlay) .

  23. z = 6.8 → 8500 Å 10300 Å Latest results: 3 z > 6.5 quasars ! z = 6.9 → ~35 min VLT/FORS2, poor conditions (seeing ~1.4”) ▪ Above, two z>6.5 quasars: YAB ~ 21.2 and 21.3 → M1450 = -25.7 Third quasar z ~ 6.6 confirmed last week. 2 more candidates awaiting spectra, total search area ~ 300 deg2

  24. Herschel-ATLAS sky coverage. Colourmap = 100um cirrus White = ATLAS Purple = DES Light blue = VIKING Green = RA/Dec lines.

  25. VIKING science – II • Herschel-ATLAS identifications (S. Fleuren). • 21,000 submm sources in GAMA-09 field; • 72% statistically detected, 50% have reliable single-object VIKING ID’s. • Galaxy evolution: • Intermediate between “local” SDSS and “deep” few deg2 VVDS, DEEP2, COSMOS , VIDEO ; • Probe evolution at z ~ 0.2 – 0.8 , in restframe 0.4 – 1.2 μm. • Galaxy Morphologies: • ~ 100,000 galaxies at z < 0.1 ; 2x better resolution and 4x deeper surface brightness limit cf SDSS. • Fundamental local benchmark sample probing all environments.

  26. VIDEO: VISTA Deep Extragalactic Observations(PI: Matt Jarvis) XMM- LSS • 12 deg2 in 3 SWIRE / SERVS fields, Ks(AB) ~ 23.5 • Science goals: • Photometric redshifts for sources from Spitzer, Herschel, SCUBA2. • Galaxy evolution, redshift ~ 1 - 3 . • High-z galaxy clusters. • Active galactic nuclei. CDF-S White = SWIRE Red = VIDEO ELAIS-S1

  27. VIDEO + Spitzer SERVS depths VIDEO SERVS

  28. Ultra-VISTA(PIs Dunlop, Franx, Fynbo, Le Fevre) • 0.75 deg2 ultra-deep + 0.75 deg2 deep. • Y, J, H, Ks + narrow 1.18 μm. • Depth near FIRES, Ks(AB) ~ 25.5; 200x area, more bands. • On Hubble-COSMOS field: • Equatorial for all-facility access, excellent data at many other wavelengths. • One HST-CANDELS field inside a deep stripe. • Science goals: • Comprehensive galaxy population, sub-L* at z ~ 2 – 4 • Ly-break galaxies, z ~ 6 – 8+ • Ly-α emitters at z ~ 8.8 .

  29. Data processing • VISTA data rate is challenging, mean ~ 200 GB/night • Dedicated Data-flow system (VDFS) • Pipeline based at CASU, Cambridge • Science Archive at WFAU, Edinburgh. • Post-processing quality control by survey teams.

  30. Complementary visible surveys • VHS: strong complementarity with VST-Atlas, DES, Skymapper, GAIA. • VIKING: matched to VST-KIDS ; also DECam/DES at CTIO, starting 2012. • VIDEO: deep visible imaging valuable, but not so critical. • DES Supernova fields likely to target VIDEO fields. • UltraVISTA: excellent visible data exists, mostly public. • Conclusion: has been bottleneck up to now in Southern visible surveys, but VST is now working, plus DES in ~ 2012. Visible data should catch up soon.

  31. Summary • VISTA has been surveying the Southern sky since late 2009. • Six major public surveys running in parallel, until ~ 2015; early data releases coming soon. • Should be world’s leading near-IR survey facility for many years (probably until Euclid / WFIRST ~ 2020 ?). • More details available at www.eso.org

  32. Possible future instrument “4MOST”: • ESO-funded design study ongoing for “4MOST” : very large multiplex , visible wide-field spectrograph. (PI: Roelof de Jong). • Fibre-fed, ~ 1500 – 2500 fibres, R > 7500, maybe 20000. • Science drivers : GAIA and E-Rosita followup, + others. • Two options under study: • 3 deg diameter FoV on VISTA , or 2 deg diameter on NTT. • In competition with VLT-MOONS for selection late 2012. • Natural future use of VISTA if Euclid goes ahead.

  33. Supplementary pretty pictures etc:

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