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Dark Energy Survey

Dark Energy Survey. 5000 sq-deg in the South Galactic Cap in 30% of 5 years (’09 –’14) 300 million galaxies, 30,000 clusters, 2000 SN- Ia 3 sq-degree camera with ≥ 2.2 deg FOV SDSS g,r,i,z filters covering 400 to 1100nm Prime Focus Cage of the Blanco Telescope

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Dark Energy Survey

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  1. Dark Energy Survey 5000 sq-deg in the South Galactic Cap in 30% of 5 years (’09 –’14) • 300 million galaxies, 30,000 clusters, 2000 SN- Ia • 3 sq-degree camera with ≥ 2.2 deg FOV • SDSS g,r,i,z filters covering 400 to 1100nm Prime Focus Cage of the Blanco Telescope We plan to replace this and everything inside it DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  2. DES Status • July 04 we received Stage 1 approval: encouragement to recruit new collaborators with funding • Aug/Sept 04: reviewed and accepted by NOAO: 30% of telescope time over 5 yrs was awarded to DES in exchange for the instrument and DM systems (est. cost of instrument $22M, DM system ~$5M) • The DES Instrument is a great improvement of the resources available to the community on the Blanco with Mosaic II • Image Area: factor of 7-8 • QE in z band: factor of 2, plus elimination of fringing • readout speed: factor of 7 • readout noise: decrease by factor of 2 • improved image quality (better focus & thermal control, PSF) DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  3. DES Focal Plane: 2.2 deg. Field of View • 62 2k x 4k CCDs for main image, • 4-side buttable, 15 micron pixels, • guide, focus CCDs on focal plane Image from Mosaic II 8 Camera on Blanco (8 CCDs) DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  4. DES Status • UC, UIUC and Fermilab contributed money for R&D • Fermilab and UIUC are contributing engineering now, potential new collaborators could contribute soon • FY05 and 06 are R&D years • CCDs: establish yield, learn to test CCDs, demonstrate packaging • Optics: finalize design, develop firm cost estimate • Front End Electronics – develop system design, begin prototyping, testing • Working with DOE to understand how to get in 2007 budget (DETF, CD0, CD1...) Goal is to be ready for first observations in Oct. 2009 DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  5. DES Organization Chart DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  6. DES Instrument project • Instrument project provides simulated and real data to Data management project DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  7. DES Instrument Reference Design Instrument Construction Organization 1.2.1 CCDs 1.2.2 CCD Packaging 1.2.3 Front End Electronics 1.2.4 CCD Testing 1.2.5 Data Acquisition 1.2.6 Camera Vessel 1.2.7 Cooling 1.2.8 Optics 1.2.9 Prime Focus Cage 1.2.10 Auxiliary Components 1.2.11 Assembly and Testing 3556 mm Camera Scroll Shutter 1575 mm Filters Optics and CCDs are the major cost and schedule drivers Optics Total ~ $2M + $1M cont. CCD Total ~ $2M + $1M cont. Optical Lenses DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  8. CCD Procurement, Packaging and Testing CCD Procurement: • Order wafers from commercial vendor through LBNL (established relationship) • LBNL performs final processing steps • Tests all devices on cold probe station • LBNL delivers all tested, unpackaged devices to FNAL at a rate of 20 CCDs/month CCD Packaging • FNAL packages and tests the CCDs • Packaging and testing at FNAL keep up with anticipated CCD delivery rate CCD Testing • Testing and acceptance criteria will be defined as we gain experience with LBNL CCDs • Multiple tilings reduces impact of bad regions DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  9. CCD Testing We are learning to operate LBNL CCDs Up to now, testing has been at – 25 C Will start testing at -100 C this week Fermilab logo projected into LBNL We can see cosmic rays. DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  10. CCD testing setup with deCube deCube Flatness measurement Optical system DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  11. Camera Vessel –Inside Cryo Spool piece CCD Cables, Feed-through board Cold Mass • Large focal plane implies long cables between CCD and electronics crates • may need to have preamps close to CCDs – inside camera or on feed through boards • Goals for readout: • noise < 5 e- • linearity <0.25% • readout rate of 250 kpix/sec Camera I/O Modules Cold Straps Focal plane DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  12. Front End Electronics and DAQ • NOAO has almost completed development of a FEE-DAQ system called Monsoon. • We decided to adopt this as the basis for our reference design • capitalize on engineering and software already developed • DES will need higher density cards (12 channel instead of 8) • Plan to use default Monsoon for initial CCD testing setups • Two Monsoon systems have been purchased with UIUC funds. One is at UIUC and the other is now at FNAL. • awaiting delivery of the 8 channel cards • Should be reading out an LBNL CCD with Monsoon by mid May 05. • Time scale is Short: • Need individual CCD testing stations (5) ready for CCD production testing and as similar to final FEE configuration as possible – Jan 07 • Final FEE system: ready to use during commissioning of the full focal plane with CCDs – March ‘08. DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  13. Monsoon Crate Implementation Two 6-slot cPCI backplanes can be put into a single crate – Image CCDs can be read out by 2 of these electronics crates. The guide CCDs will have their own small crate. DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  14. Outside World context TCS GUI Image Display Status Display Observation Scheduler DB & Archive Exposure control Data & Message Buses Acquisition process Guider process Instrument control process Instr. Process Monsoon I Monsoon II Instrument controller Cryo controller Controller Filter Wheel FPA (RTDs) FPA (CCDs) Guide & focus CCDs Shutter Cryogenics Camera Instrument Control System DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  15. DES Image Simulation • DES will be the largest CCD camera of its time. Each image: • 3 sq. deg. • ~ 20 Galaxy clusters • ~ 200,000 Galaxies • 0.5 Giga pixels (62 CCDs) • Each night ~ 300 GB of image data • Entire survey ~ 500 TB • Image is derived from SDSS coadd data to simulate DES images. Added • Detector effects: noise, un-flattened • Optical effects: sky levels, pupils • Plenty of work to do here too! courtesy of F. Valdes/NOAO

  16. DES Instrument Cost Estimate (then yr $M, no overhead) • M&S: 8.3M + 3.1M Cont. = $11.4M • Labor: 4.8M + 2.4M Cont. = $7.2M • Institutional Overhead est = $4M Have asked DOE to provide 2/3 of M&S = $7.4M We are working to raise $4M from external sources UC, UIUC funding – already in MOUs = $0.9 M – being used for R&D UK and Barcelona have submitted proposals to their funding agencies We anticipate applications from several universities DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  17. Data Management System Reliably transfer ~300GB/night produced on 500 nights over 5 years from CTIO to NCSA Process data at NCSA, provide to DES team and community Maintain DES archive over the long term Data Management Strategy Leverage existing solutions (SM/SN, NSA) Coordinate with LSST DM (@NCSA) and NOAO DPP in addition to the key DES teams at Fermilab and U Illinois Early Community Access to Data/Pipelines Raw and reduced data (1 yr after acquisition) Co-add and catalogs (at midpt and again at end of survey) Data Management Overview DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  18. DES Processing Pipelines Processing framework NCSA-LSST Astronomy modules U Illinois, Fermilab DES Archive Image data storage NOAO DPP Catalog data storage NCSA-DES Data access framework NCSA-LSST Replication tools NCSA-DES Observer Tools/Data Transfer Quality assurance on the mountain DPP, U Illinois Reliable data transfer from CTIO to NCSA NCSA-LSST/DES Observer expert system DPP, U Illinois DM System Overview DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  19. Development strategy Base level system in place after first year Development continues on this system and new components are added Full system validated in early 2009, stress test of processing and archiving component carried out in previous year Development punctuated by yearly data challenges Data Challenge 1 (Oct ‘05): Grid-processing framework, image data archive, astronomy modules Data Challenge 2 (Oct ‘06): All of the above plus catalog database, automated quality assessment, global photometric calibration and archive replication Data Challenge 3 (Oct ‘07): All of the above with stress test (full year of mock data) Data Challenge 4 (Oct ‘08): Test refinements for archive & pipelines, add Observing tools Data Management Development Schedule DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  20. DES Science Projects:General Principles • Scientific analyses of the DES data will be done collaboratively by the DES participants. Participation in science projects that use DES data will be open to all DES participants. • When ever one or more DES participants wish to start a science project with processed DES data, including catalogs, that have not been released to the public they will be required to post a general description of the proposed analysis on the Science Working Group website (to be established) and invite other DES participants to join. DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  21. The Science Working Group • The members of the Science Working Group will be appointed by the Management Committee (MC). • The MC will appoint the leaders of the key projects and appoint them to the Science Working Group. • The MC will delegate the responsibility of assuring that the key projects are well run to the Science Working Group, while retaining oversight over the SWG. DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  22. Dark Energy Key Projects Four Probes of Dark Energy • Galaxy Cluster Counting: N(M,z) • Measure red shifts and masses • 20,000 clusters to z=1 with M > 2x1014 M • Weak lensing • 300 million galaxies with shape measurements over 5000 sq deg. • Spatial clustering of galaxies • 300 million galaxies to z = 1 and beyond • Standard Candles • 2000 SN Ia, z = 0.3-0.8 DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  23. A Cluster of Galaxies in SDSS Data What is the cluster redshift? What is the cluster mass? not completely different from jet clustering in collider physics but also have depth (red shift) info. DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  24. Additional possible projects: • Strong lensing • The growth of galaxy structures on scales greater than 1 Mpc • Search for biasing parameters • QSOs • Search for very low mass stars and brown dwarfs • Statistical properties of the initial conditions • Many more possibilities! DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  25. Summary (1) • We have initiated an R&D program with funds from FNAL, UIUC and Chicago. Looking for collaborators and funding to make it stronger • FEE schedule is aggressive: Hard to predict what will be needed in Jan. 06! • We are just at the beginning: • Need to read out a CCD with Monsoon • Need to understand cable length issue • Need to understand grouping of CCDs • Read out at 250 kpix/s noise < 5e- • Goals: Sept. 05 – prototype 12 channel card • Jan. 06 – multi CCD readout? DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  26. Summary (2) • Starting to think about how to integrate DAQ and DES controls with Blanco controls and other systems – Blanco TCS is going to evolve to something similar to what is used on SOAR – MSU has experience? • Working to get better understanding of telescope and sight seeing • DM project is taking shape, lots of work to do here too! • Schedule: • R&D in 05 and 06 • Construction in 07-09 • DES survey observing Oct. 2009-Feb 2013 DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

  27. Optics Design: UCL and Chicago Corrector • 2.2 deg. FOV Corrector (Kent, Gladders) • 5 powered elements (Fused Silica) • one aspheric surface (C4) • four filters – griz • UCL and the Optical Science Center • are obtaining quotes from vendors • submitted proposal to PPARC • Steve Kent (Chicago) is developing optical design requirements for weak lensing measurement • Found that PSF shape (e.g. the WL signal) is sensitive to horizontal offsets between corrector and mirror • working with CTIO to understand mechanical stability of the mirror and telescope DES Meeting in Michigan April. 2005 Fermilab, U Illinois, U Chicago, LBNL, CTIO/NOAO, Barcelona, UCL, Cambridge, Edinburgh

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