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Shapelet Space STEP

Shapelet Space STEP. F. William High , Research Assistant Caltech Tuesday, July 26, 2005. Overview. Set σ γ / n 1/2 ~ 0.1% n g ~ 100/arcmin 2 σ γ ~ 0.3 n im = 50 or 100 Various θ px HDF Galaxies (mostly) Raytraced PSFs FOV 200”x200” SNAP 160”x160” ACS. T exp 1 ks SNAP wide

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Shapelet Space STEP

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  1. Shapelet Space STEP F. William High, Research Assistant Caltech Tuesday, July 26, 2005

  2. Overview • Set σγ/n1/2 ~ 0.1% • ng ~ 100/arcmin2 • σγ ~ 0.3 • nim = 50 or 100 • Various θpx • HDF Galaxies (mostly) • Raytraced PSFs • FOV • 200”x200” SNAP • 160”x160” ACS • Texp • 1 ks SNAP wide • 2 ks ACS WFPC2 • Uniform across “chip”: • Depth • Noise • Input shear • PSF HDF Change orientation, size, flux, Shapelets Measure Shapelets PSF convolve Shear Raytraced PSFs Shapelet Space STEP

  3. The Stars • Our PSFs account for: • Diffraction, including struts • Charge diffusion Convolve in Shapelet space One globular cluster per psf* Shapelet Space STEP

  4. The Galaxies Logarithmic grayscale Shear to 4th order in Shapelet space Shapelet Space STEP

  5. The Noise • Shot noise: readout, zodiacal (but background subtracted) • Exposure timetexp = ~1 ks SNAP, ~2 ks ACS • Larger θpx @ fixed texp↔ larger noise & signal-to-noise • Perfect Charge Transfer Efficiency • Uncorrelated: pre-drizzle Shapelet Space STEP

  6. The Result Shapelet Space STEP

  7. Conclusion • 962 images, 7-11 arcmin2, 40 Gb total • ftp://www.astro.caltech.edu/pub/fwh/SpaceSTEP/ • 100+ parallel processors @ NERSC/LBL • Email Will (fwh@astro.caltech.edu) and Richard (rjm@astro.caltech.edu) with questions • Deadline: mid-September Shapelet Space STEP

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