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Dark Energy Constraints from BA0

Dark Energy Constraints from BA0. Wang Yun astro/ph 0601163. Need factor 10 improvement for w’ measurement to 0.1!. Need good z resolution. Wang Yun astro/ph 0601163. Cosmos (HST) Ground optical follow-up for photoz D z/(1+z)=0.031!. What about space and radiotelescopes?.

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Dark Energy Constraints from BA0

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  1. Dark Energy Constraints from BA0 Wang Yun astro/ph 0601163

  2. Need factor 10 improvement for w’ measurement to 0.1! Need good z resolution Wang Yun astro/ph 0601163 Cosmos (HST) Ground optical follow-up for photoz Dz/(1+z)=0.031! What about space and radiotelescopes?

  3. 21 cm redshift survey to constrain dark energy Jeff Peterson and Ue-Li Pen (March 2006 Moriond) • Use acoustic oscillations from z = 0 to z = 1.5 to detail the transition from deceleration to acceleration. • Survey 2 Pi steradians from 500 to 1500 MHZ with a 250,000 sq m fixed-pointed meridian-scan radio telescope. • Cylindrical reflectors allow for ultra-wide field observations, and inexpensive FFT based beam forming. • Modest cost--$20M--$0.02/redshift

  4. Four Cylinders each 2 (3?) km long N 2 (3 )km

  5. Cylindrical reflectors use suspended mesh, with a line of feed pointsReflector Cost: ~$20/m^2Survey Speed~A*N

  6. Darwin AUSTRALIA Brisbane Sydney Perth + Molonglo Adelaide Canberra Melbourne Hobart Existing cylinders MOLONGLO Cost:$12/m^2 (current dollars) OOTY Both rotate in one dimension

  7. Cylinder History • Popular 1960-1980 • Lost favor with advent of cryogenically cooled pre-amplifiers. • Room temp amplifiers with 20K noise temp now available. Illinois 400 ft Telescope ca. 1960

  8. Dark Energy Constraint vs. redshift limit Blake and Glazebrook

  9. Conclusions Peterson • Using off the shelf technology, a redshift survey telescope can be built for modest cost ($20M) which will yield 10^9 redshifts to z~1.5 • Will cover 100 times the SDSS volume • Will constrain w1 to ~0.1 ???? 200 M ???? =SKA/10 w=w0+w1z Many questions on feasability and price! • Why not use existing facilities? Han JinLin • EVLA • FAST: need to develop fast correlators

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