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Joint Efficient Dark-energy Investigation (JEDI)

Joint Efficient Dark-energy Investigation (JEDI). Yun Wang May 25, 2006. beware of the dark side … Master Yoda. JEDI Prototype: Ultra Deep Supernova Survey on a dedicated telescope (1998). To determine whether SNe Ia are good cosmological standard candles, we need to nail the systematic

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Joint Efficient Dark-energy Investigation (JEDI)

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  1. Joint Efficient Dark-energy Investigation (JEDI) Yun Wang May 25, 2006

  2. beware of the dark side … Master Yoda Yun Wang, May 25, 2006

  3. JEDI Prototype:Ultra Deep Supernova Survey on a dedicated telescope (1998) To determine whether SNe Ia are good cosmological standard candles, we need to nail the systematic uncertainties (luminosity evolution, gravitational lensing, dust). This will require at least hundreds of SNe Ia at z>1. This can be easily accomplished by doing an ultra deep supernova survey using a dedicated telescope, which can be used for other things simultaneously (weak lensing, gamma ray burst afterglows, etc). Wang (astro-ph/9806185)

  4. Go Deep!(get a lot more SNe at z>1) Wang & Lovelave 2001, ApJ Lett 562, 115 Optimal for measurement of dark energy density: Yun Wang, May 25, 2006

  5. Apply the idea for an ultra deep SN survey to a space platform: Space, the final frontier … Yun Wang, May 25, 2006

  6. Joint Efficient Dark-energy Investigation (JEDI): a candidate implementation of the NASA-DOE Joint Dark Energy Mission (JDEM)

  7. JEDI Collaboration PI: Yun Wang (U. of Oklahoma) Deputy PI: Edward Cheng (Conceptual Analytics) Lead Scientists: Interdisciplinary: Arlin Crotts (Columbia), Tom Roellig (NASA Ames), Ned Wright (UCLA) SN : Peter Garnavich (Notre Dame), Mark Phillips (Carnegie Observatory) WL: Ian Dell’Antonio (Brown); BAO: Leonidas Moustakas (JPL/Caltech) Eddie Baron (U. of Oklahoma) Steve Bender (LANL) David Branch (U. of Oklahoma) Stefano Casertano (Space Telescope Insti.) Bill Forrest (U. of Rochester) Salman Habib (LANL) Tom Hale (LANL) Mario Hamuy (U. of Chile) Katrin Heitmann (LANL) Alexander Kutyrev (NASA GSFC) John MacKenty (Space Telescope Insti.) Craig McMurtry (U. of Rochester) Judy Pipher (U. of Rochester) William Priedhorsky (LANL) Robert Silverberg (NASA GSFC) Volker Springel (Max Planck Insti.) Gordon Squires (JPL/Caltech) Jason Surace (JPL/Caltech) Max Tegmark (MIT) Craig Wheeler (UT Austin) Yun Wang, May 25, 2006

  8. JEDI Support NASA JPL: Program Management Lockheed Martin: Mission and Spacecraft ITT/Rochester: Telescope and Instrument Rockwell Scientific: Focal Plane Assemblies Yun Wang, May 25, 2006

  9. JEDI will answer these questions: • Is dark energy a cosmological constant? • Does Einstein’s general relativity describe our Universe? Yun Wang, May 25, 2006

  10. What’s special about JEDI: • Super Efficiency: Takes >5000 spectra (including all the supernovae in the field of view) simultaneously – super efficiency for SNe, and ideal for spectroscopic galaxy surveys (measuring radial baryon acoustic oscillations and calibrating photo z’s for weak lensing) • Focus on What Can’t be Done From the Ground: Covers the wavelength range (near to mid IR) not easily accessible from the ground, and better for the control of systematics • Multiple Methods for Accurate and Precise Constraints on Dark Energy: SNe, WL, BAO, etc Yun Wang, May 25, 2006

  11. Microshutter Arrays: AAS 205, [5.07] Microshutter Arrays for JWST NIRSpec., S. H. Moseley et al. Each shutter consists of a shutter blade suspended on a torsion beam (from a support grid) that allows for a rotation of 90°. A motor opens the shutters with a specially formed magnet as a remote controlling tool. 2D programmable slit mask Yun Wang, May 25, 2006

  12. - lowest sky background region within ~0.3-100 µm wavelengths - rest wavelengths in red/near-IR for redshifts 0 < z < 4 JEDI: exploiting 0.8-4 µm “sweet spot” Background sky spectrum: Leinert 1998, A&AS, 127, 1

  13. JEDI: Necessity of Space Observations Supernovae as standard candles: 1) Observation of z > 1 SNe Ia (tightens constraints on time variation of DE). 2) Rest J lightcurves for all SNe Ia (better standard candles – Krisciunas et al. 2004). 3) Multiple spectra per SN Ia (provide constraints on systematics). Baryon acoustic oscillations as a standard ruler: 1) Efficiently harvest millions of galaxy redshifts in the contiguous range 0.5<z<2. 2) H(z) measured as a continuous free function. Weak lensing cosmography: 1) Stable and smaller point spread function. 2) Higher galaxy density and higher mean galaxy redshift from deep NIR imaging. 3) Spectroscopic reshift information for tomography. Continuous H(z) to better than 2% in z~0.2 bins for 0  z  2. Yun Wang, May 25, 2006

  14. JEDI: the Power of Three Independent Methods Supernovae as standard candles: luminosity distances dL(zi) Baryon acoustic oscillations as a standard ruler: cosmic expansion rate H(zi) angular diameter distance dA(zi) cosmic LSS growth rate G(z) Weak lensing cosmography: ratios of dA(zi)/dA(zj) cosmic LSS growth rate G(z) The three independent methods will provide a powerful cross check, and allow JEDI to place precise constraints on dark energy. Yun Wang, May 25, 2006

  15. Measurement of the Cosmic Expansion History Current JEDI Wang & Tegmark (2005); Wang & Mukherjee (2006); Wang (2006) The JEDI mission will measure H(z) for 0 < z < 2 using both SNe and Baryon Acoustic Oscillations (BAO), thus enabling model-independent constraints on the time dependence of dark energy Yun Wang, May 25, 2006

  16. JEDI Data: • Supernovae: ~ 4000-14,000 type Ia supernovae with well-sampled light curves and good quality spectra. • Baryon Acoustic oscillations data: ~ 10-100 million galaxy spectra (H emission line galaxies) over ~ 1000-10,000 square degrees, with 0.5 ≤ z ≤ 2. • Weak lensing data: accurate measurements of galaxy shapes over ~ 1000-10,000 square degrees to H  23 (median redshift 1 to 1.5). • Shear selected galaxy clusters over 10,000 sq degrees • Other (what data would you like to have?) Yun Wang, May 25, 2006

  17. JEDI science requirements map directly into instrument design parameters JEDI builds upon heritage from Spitzer and technology from JWST. Yun Wang, May 25, 2006

  18. Key Scientific Requirements Flowdown

  19. Yun Wang, May 25, 2006

  20. JEDI’s preliminary optical design provides a proof-of-concept point design combiningimaging and spectroscopic performance in a compact, packagable design. Further simplifications may be the results of design studies performed during the concept study. Yun Wang, May 25, 2006

  21. The JEDI spacecraft easily fits within the payload envelope of the Delta IV 4 meter configuration shown. Yun Wang, May 25, 2006

  22. JEDI will use the JWST/NIRSpec microshutter array without modification. Yun Wang, May 25, 2006

  23. The HAWAII-2RG multiplexer, used in both focal planes, has extensive ground based heritage. Yun Wang, May 25, 2006

  24. Spectrograph Sky Coverage Imaging Sky Coverage The unique sky coverage of the JEDI focal planes allows identification of spectrographic targets by the imager due to the offset of the imaging and spectral focal planes. Yun Wang, May 25, 2006

  25. JEDI Deep Campaign The spacecraft repeats a pattern that allows spectral targets to be identified by imaging and selected by the microshutters on the following scan line. Yun Wang, May 25, 2006

  26. JEDI Wide Campaign JEDI scans successive quadrants while obeying sun and pointing constraints. Imaging provides spectroscopy targets as in the Deep Campaign. Yun Wang, May 25, 2006

  27. Functional Concept a) the flight segment mounted in the fairing of a Delta-IV 4-m configuration. b) FOVs of the imaging and spectroscopic channels projected onto the sky. c) a preliminary optical point design demonstrates that the desired functions are packageable. d) an exploded view of the JWST/NIRSpec microshutter array. This exact hardware is baselined for JEDI. Practical packaging constraints for this hardware cause the small horizontal gap between the two spectroscopic fields-of-view in panel (b). e) a mechanical mockup of a 5x7 focal plane array built by RSC to demonstrate fabrication and alignment processes. f) a single hybrid detector basedon HAWAII-2RG design, being produced for 3 JWST instruments. Yun Wang, May 25, 2006

  28. Competing Mission Concepts for JDEM:SNAP, JEDI, DESTINYADEPT, DUNE (?), X, Y Competition helps ensure that the best science gets done … Yun Wang, May 25, 2006

  29. JDEM Timeline • July 2006: proposals selected for NASA JDEM concept study (up to $2M a year for two years) • ~ 2008: NASA/DOE Announcement of Opportunity (AO) for JDEM • ~ 2017: JDEM launch Yun Wang, May 25, 2006

  30. Conclusion • A successful JDEM can place robust and precise constraints on the time dependence of X(z) and G(z). This will have a fundamental impact on particle physics and cosmology. • JEDI is a powerful mission concept for JDEM. • JEDI has unprecedented capability for ancillary science. Yun Wang, May 25, 2006

  31. The End Yun Wang, May 25, 2006

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