1. anadian ydrogen ntensity apping xperiment CHIMECHIME CHIMECHIME WiggleZ Dark Ages Stars 13.7Gy CMB Big Bang Reionization 1100 z∞ 50 95321 SDSS 7Gy CHIME 300ky 0 500My Age of Universe Keith Vanderlinde CIfAR C&G 2012 AGM

2. Outline Cosmo Context HI Mapping of BAO FFT Telescopes CHIME anadian ydrogen ntensity apping xperiment Keith Vanderlinde CIfAR C&G 2012 AGM CHIMECHIME CHIMECHIME

3. Composition of the Universe Composition Images from NASA / WMAP Science Team w = -1 ± 0.2 Frieman et al. 2008 -4 -3 -2 0 1 Log (a) ? Can study via growth of space. Need standard ruler over wide z range!

4. The Primordial Plasma Photons Neutrinos Dark Matter Electrons + Baryons Hu & White, Scientific American, 2004

5. Baryon Acoustic Oscillations random background of primordial fluctuations each fluctuation emits a pressure wave at decoupling, the size of this wave is frozen (Eisenstein) Komatsu et al. 2010 Cold Stack Hot Stack Measured in the CMB

6. Post-Decoupling Radial Profile BAO are “frozen in,” ~150 co-moving Mpc. BAO peak Eisenstein

7. Buetler et al, 2011 6dFGS BAO Observations Blake et al, 2011 WiggleZ Detected in galaxy correlations! SDSS Eisenstein et al, 2005  m h 2 = 0.12,  m h 2 = 0.024  m h 2 = 0.13,  m h 2 = 0.024  m h 2 = 0.14,  m h 2 = 0.024  m h 2 = 0.105,  m h 2 = 0.0 Sanchez et al, 2012 BOSS-CMASS

8. BAO as a standard ruler 1100 WMAP... BAO “Size” at z How do we fill this in? Anderson et al. 2012

9. Optical Maps of Structure Sloan Digital Sky Survey (SDSS) Blanton et al. (2003) Get spectroscopic redshifts on lots of galaxies. Works! But: expensive hard at z>1 BAO Scale BAO Scale

10. Hydrogen Intensity Mapping For BAO, no need to resolve galaxies individually. Use 21cm HI line. For 15 co-moving Mpc resolution at z~1-2 (~20’), need: Unresolved galaxies, resolved BAO. BAO Scale BAO Scale a)100m telescope + decades of survey b)Interferometer + HUGE correlator c)FFT telescope (See Ue-Li’s talk!)

11. FFT Telescope Haslam et al. 1982 + + + + + + + Sky Ground E Sampled Ground Measured Sky

12. Normal Telescope x Use a mirror (or lens) to focus light onto a detector. noise ~ T sky + T amp

13. x x x x x x x x x Phased Array Interferometer Record signals at the dish, add delay to mimic reflection, sum recorded signals. noise ~ T sky + T amp sqrt(N amp )

14. Phased Array Interferometer x x x x x x x x x Throw away the dish. Save a big pile of money. noise ~ T sky + T amp sqrt(N amp )

15. “Pointing” a Phased Array x x x x x x x x x Add delays with cabling to mimic pointing. Spend your pile of money on a computer, do this digitally. noise ~ T sky + T amp sqrt(N amp )

16. Beam-forming Telescopes x x x x x x x x x Record signals on the ground, digitally delay and add. N beams, without aliasing, for spacing < /2. Mapping speed ~ N ant x single-dish. (N 2 for T sky >> T amp ) noise ~ T sky + T amp sqrt(N ant ) -- per beam! --

17. Cylinder Telescopes Hybrid: 1D Dish + 1D FFT Single Antenna Long Narrow Beam

18. Cylinder Telescopes Hybrid: 1D Dish + 1D FFT N antennas N “Formed Beams” FFT

19. 100m 400-800MHz band 21cm from z ~ 0.8 - 2.5 Resolution: 1MHz, 13-26’ <10% BAO scale Drift scan, no moving parts 20,000 deg 2 coverage C anadian H ydrogen I ntensity M apping E xperiment

20. 1 2 Record Data Readout & Correlator 1) Sample & channelize 1 ADC per antenna 8-bit @ 800MSPS 2) Correlate 1 node per freq band N 2 is tricky: Pflops of processing, Exabytes of storage (!!) Do FFT beamforming, plus partial N 2 to calibrate

21. CHIME Sensitivity to BAO spectrum w/ BAO spectrum w/o BAO

22. CHIME Cosmology Forecast (1+z) 3 ^ (Preliminary!)

23. Pulsars & Radio Transients Every day, CHIME observes: every point in the northern celestial hemisphere across an octave in frequency (400-800MHz) for between 5 minutes and hours (depending on Decl.) with  s timing resolution & accuracy Can’t actually process every point at that rate. Tee data off to monitor known locations, systematically search for new sources.

24. Mapping the Observable Universe Dark Ages WiggleZ Stars 13.7Gy CMB Big Bang Reionization SDSS 1100 z∞ 50 95321 7Gy CHIME (400 co-moving Gpc 3 ) 300ky 0 500My Age of Universe CHIME will: survey BAO measure the growth of space from 0.8<z<2.5 over a volume of ~400 co-moving Gpc 3

25. CHIME Survey Volume For cosmic variance limited survey, sensitivity ~ volume. CHIME’s sensitivity to D.E. within ~2x of c.v. limited.

26. The End