A SkyMapper Update Stefan Keller

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 2 Who is SkyMapper? Brian Schmidt (PS) Mike Bessell Peter Conroy Paul Francis Andrew Granlund Stefan Keller Errol Kowald A. Paddy Oates Tony Martin-Jones Tim Preston Patrick Tisserand Annino Vaccarella Mark Waterson

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 3 What is SkyMapper? 1.35m telescope with a 5.7 sq. degree field of view To conduct the Southern Sky Survey: Five year Multi-colour (6 filters) Multi-epoch (6 exposures, each filter) 2  steradians Limiting mag. g~23 Aiming for regular operations mid 2008 Summary of program: Keller et al astro-ph

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 4 The Rapid Imaging Survey Era We aim to fill the gap in the coverage of the Southern sky, matched to SDSS but with significant improvements: sky + temporal coverage; sensitivity to stellar parameters NameAperture (m) FOV (sq deg) Filter Set Areal Coverage Hemi sphere First Light SDSS2.5Drift scanugrizπ of 3/2πNOperating CFHT MegaCam 3.61ugriz<1000NOperating SkyMapper uvgriz2 πS2007/8 PanStarrs1.8 (+3x)7grizY3 πN2007 VISTA41.65zYJHK2 πS2008 VST2.61ugriz~5000S2008 Discovery Chn42??N20010? Dark Energy42?5000S LSST8.410ugrizY3 πS2013+

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 5 Where is the SkyMapper Telescope?

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 6 The SkyMapper Telescope

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 7

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 8 The SkyMapper Enclosure Level 3 Observing Space Level 2 Service Level Level 1 Thermally Isolated Equipment Level Rear Shutter Front Shutter Vent Door 6m diameter 11.5m tall

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 9 Lightning Protection A high incidence of lightning strikes in the vicinity (3/km 2 /yr) Four air terminals mounted on the dome to ground plane of copper braid Commercial lightning detection warning park telescope in preferred orientation

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 10 Telescope Optics 1.3m primary 0.75m secondary 0.6m fused silica asphere 2 x 0.45m fused silica spherics Telescope – Focal length & f/ ratio mm f/4.78 Modified Cassegrain design

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 11 SkyMapper Cassegrain Imager Being built by RSAA 16384x16384 pixel array Cooled with Closed-Cycle He system Off-axis guider Shack-Hartmann system for collimation, etc. 6 Filters slots (< 20 second exchange time) Bonn shutter (2ms accuracy) GuiderShack-Hartmann Filters Shutter

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 12 The SkyMapper CCDs 32 E2V CCD44-82 devices: 2048x micron pixel CCDs Broadband coated 40 micron (thick) deep depletion devices Reduced fringing, inc. red response 16384x ” pixels Using new Pan Starrs controllers (Onaka) Readout in ~10-20seconds Readnoise ~8e 12 seconds

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 13 The Design of the Southern Sky Survey

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 14 The Southern Sky Survey 2π coverage: 4096 fields observed in six filters, six times per filter Cadence: hours, days, weeks, months, years star/galaxy photometry to 3% globally (g<18) astrometry to 50 (15 relative) milliarcsec (absolute) 36 images of each object over 5 years – ⇒ proper motions to ±5(2) mas/yr. (i.e. σvtan=25km/s at 2.5 (6)kpc) – ⇒ parallax ±5 (2) mas (i.e. 20pc (50) σd=10%) survey complete in 5 years

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 15 SkyMapper Filter Set Ex-atmosphere

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 16 Expected Survey Limits uvgriz 1 epoch epochs Sloan Digital Sky Survey comparison 22.0n/a AB mag. for signal-to-noise = 5 from 110s exposures

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 17 Calibration Plans Understanding the illumination correction is fundamental In commissioning construct Illum. Corr. via dithered observations of a field Then rotate instrument and repeat... Develop 6 reference fields spaced in RA at dec~-20 V+R from ESO 2.2m (Koch+03)

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 18 Conduct Five-Second Survey in photometric conditions cover the southern sky w. 3x5 exposures: 8- 15th mag During 5-s observe the highest two reference fields every 90 minutes primary standards: Stars in Walraven system with STIS spectrophotometry Anchor the deeper Main Survey to the Five-Second photometry and astrometry Enables the Main Survey to proceed under non-photometric conditions. Calibration Plans

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 19 What is in the Database Raw Images, Flatfielded images, combined images Photometry - aperture, PSF, Kron, Petrosian Astrometry - Derived quantity datasbase –parallax,proper motion –image id (QSO, galaxy, star(type)

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 20 Science Programs Utilising the Southern Sky Survey -Extremely Metal-Poor Stars -Galactic Structure -QSOs -Stromlo Missing Satellite Survey -Young Stars -Solar System Keller Da Costa Tisserand Jerjen Bessell Francis Science Programs External to the Southern Sky Survey -Planetary Transit Search -GRB + Low-z SNe -MgII of Southern Sky -Ha of Southern Sky -Variable Stars Sackett Schmidt Freeman Bessell Wood MORE WELCOME

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 21 Blue Horizontal Branch Stars ZAHB MS+BS logg=2 logg=5 takes us out to distances >100kpc with low contamination Teff: 10000K6000K HBARRL

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 22 Blue Horizontal Branch Stars The SDSS view Use a set of colour and spectroscopic indices to isolate BHBs Extend to 60kpc The SkyMapper View Photometric BHB selection to 130kpc with 5% contamination + RRLs obtained from time series From Sirko et al. 2004

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 23 Extremely Metal-poor Stars in the Halo Goal: find the first stars to have formed in the Universe: tell us about the assembly and chemical enrichment of the Galaxy v-g is dependent on the level of metal line blanketing in the blue continuum ✓ not perturbed dramatically by C-enhancement, chromospheric emission as affects objective-prism surveys FG

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 24 Extremely Metal-poor Stars in the Halo Scale HES numbers for increased area, depth Select a sample with photometrically derived [Fe/H]<-4 and g<18 returns this sample of spectroscopic [Fe/H] ~130 [Fe/H]<-5

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 25 Data Release Deliverables to the Outside User: -Data (epoch, RA, DEC, mags, galaxy shape info,…) to be available through a web-served interface which provides catalogs over a user defined area -Images to be available through a web-served interface which provides images over a user defined area Data release will occur after extensive data validation: -Five-Second data after closure in RA and trial application to concurrently obtained main-survey data -FDR Main Survey 3 epochs all filters -SDR Main Survey 6 epochs all filters FL+1.5yrs FL+>3yrs

Stefan Keller SkyMapper FoF June Southern Sky Survey Slide 26 Progress –DONE Telescope has had first light in Jul in Tucson Final integration of imager undergoing Filters on track by end of year Dome done Software pipeline finishing up Telescope delivery (Jan?) Imager Delivery (Mar) Regular Observations 2008