A Sky Mapper Update Stefan Keller Southern Sky

A Sky. Mapper Update Stefan Keller

Southern Sky Survey Who is Sky. Mapper? 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 Sky. Mapper Fo. F June 8 2007 Slide 2

Southern Sky Survey What is Sky. Mapper? • 1. 35 m 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) • 2π steradians • Limiting mag. g~23 • Aiming for regular operations mid 2008 • Summary of program: Keller et al. 2007 astro-ph 0702511 Stefan Keller Sky. Mapper Fo. F June 8 2007 Slide 3

Southern Sky Survey The Rapid Imaging Survey Era Name Aperture (m) FOV (sq deg) Filter Set Areal Coverage Hemi sphere First Light SDSS 2. 5 Drift scan ugriz π of 3/2π N Operating CFHT Mega. Cam 3. 6 1 ugriz <1000 N Operating Sky. Mapper 1. 35 5. 7 uvgriz 2π S 2007/8 Pan. Starrs 1. 8 (+3 x) 7 griz. Y 3π N 2007 VISTA 4 1. 65 z. YJHK 2π S 2008 VST 2. 6 1 ugriz ~5000 S 2008 Discovery Chn 4 2 ? ? N 20010? Dark Energy 4 2 ? 5000 S 20010+ LSST 8. 4 10 ugriz. Y 3π S 2013+ • 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 Stefan Keller Sky. Mapper Fo. F June 8 2007 Slide 4

Southern Sky Survey Where is the Sky. Mapper Telescope? Stefan Keller Sky. Mapper Fo. F June 8 2007 Slide 5

Southern Sky Survey The Sky. Mapper Telescope Stefan Keller Sky. Mapper Fo. F June 8 2007 Slide 6

Southern Sky Survey Stefan Keller Sky. Mapper Fo. F June 8 2007 Slide 7

Southern Sky Survey The Sky. Mapper Enclosure Rear Shutter Front Shutter Level 3 Observing Space 11. 5 m tall Level 2 Service Level Vent Door Level 1 Thermally Isolated Equipment Level Stefan Keller 6 m diameter Sky. Mapper Fo. F June 8 2007 Slide 8

Southern Sky Survey 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 Sky. Mapper Fo. F June 8 2007 Slide 9

Southern Sky Survey Telescope Optics 0. 75 m secondary Modified Cassegrain design 0. 6 m fused silica asphere 1. 3 m primary 2 x 0. 45 m fused silica spherics Stefan Keller Telescope – Focal length & f/ ratio. Sky. Mapper Fo. F June 8 2007 16224. 75 mm f/4. 78 Slide 10

Southern Sky Survey Sky. Mapper Cassegrain Imager • Being built by RSAA • 16384 x 16384 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 (2 ms accuracy) Guider Shack-Hartmann Filters Shutter Stefan Keller Sky. Mapper Fo. F June 8 2007 Slide 11

Southern Sky Survey The Sky. Mapper CCDs • 32 E 2 V CCD 44 -82 devices: 2048 x 4096 15 micron pixel CCDs • Broadband coated • 40 micron (thick) deep depletion devices • Reduced fringing, inc. red response • 16384 x 16384 0. 5” pixels • Using new Pan Starrs controllers (Onaka) • Readout in ~10 -20 seconds • Readnoise ~8 e- @ 12 seconds Stefan Keller Sky. Mapper Fo. F June 8 2007 Slide 12

Southern Sky Survey The Design of the Southern Sky Survey Stefan Keller Sky. Mapper Fo. F June 8 2007 Slide 13

Southern Sky Survey 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=25 km/s at 2. 5 (6)kpc) – ⇒ parallax ± 5 (2) mas (i. e. 20 pc (50) σd=10%) • survey complete in 5 years Stefan Keller Sky. Mapper Fo. F June 8 2007 Slide 14

Southern Sky Survey Sky. Mapper Filter Set Ex-atmosphere Stefan Keller Sky. Mapper Fo. F June 8 2007 Slide 15

Southern Sky Survey Expected Survey Limits u v g r i z 1 epoch 21. 5 21. 3 21. 9 21. 6 21. 0 20. 6 6 epochs 22. 9 22. 7 22. 9 22. 6 22. 0 21. 5 Sloan Digital Sky Survey comparison 22. 0 n/a 22. 2 21. 3 20. 5 AB mag. for signal-to-noise = 5 from 110 s exposures Stefan Keller Sky. Mapper Fo. F June 8 2007 Slide 16

Southern Sky Survey 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. 2 m (Koch+03) Stefan Keller Sky. Mapper Fo. F June 8 2007 Slide 17

Southern Sky Survey Calibration Plans • Conduct Five-Second Survey • in photometric conditions cover the southern sky w. 3 x 5 exposures: 815 th 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. Stefan Keller Sky. Mapper Fo. F June 8 2007 Slide 18

Southern Sky Survey 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 Sky. Mapper Fo. F June 8 2007 Slide 19

Southern Sky Survey 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 MORE WELCOME Science Programs External to the Southern Sky Survey -Planetary Transit Search -GRB + Low-z SNe -Mg. II of Southern Sky -Ha of Southern Sky -Variable Stars Stefan Keller Sackett Schmidt Freeman Bessell Wood Sky. Mapper Fo. F June 8 2007 Slide 20

Southern Sky Survey Blue Horizontal Branch Stars MS+BS logg=5 logg=2 ZAHB HBA Teff: 10000 K Stefan Keller RRL 6000 K takes us out to distances >100 kpc with low contamination Sky. Mapper Fo. F June 8 2007 Slide 21

Southern Sky Survey Blue Horizontal Branch Stars • The SDSS view • Use a set of colour and spectroscopic indices to isolate BHBs • Extend to 60 kpc • The Sky. Mapper View • Photometric BHB selection to 130 kpc with 5% contamination • + RRLs obtained from time series From Sirko et al. 2004 Stefan Keller Sky. Mapper Fo. F June 8 2007 Slide 22

Southern Sky Survey 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 Stefan Keller F Sky. Mapper Fo. F June 8 2007 G Slide 23

Southern Sky Survey Extremely Metal-poor Stars in the Halo Scale HES numbers for increased area, depth ~130 [Fe/H]<-5 Stefan Keller Select a sample with photometrically derived [Fe/H]<-4 and g<18 returns this sample of spectroscopic [Fe/H] Sky. Mapper Fo. F June 8 2007 Slide 24

Southern Sky Survey 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 FL+1. 5 yrs -FDR Main Survey 3 epochs all filters -SDR Main Survey 6 epochs all filters FL+1. 5 yrs FL+>3 yrs Stefan Keller Sky. Mapper Fo. F June 8 2007 Slide 25

Southern Sky Survey 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 Stefan Keller Sky. Mapper Fo. F June 8 2007 Slide 26