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WFC3 Grisms Results from TV2 2D Simulations. Harald Kuntschner, Jeremy Walsh, Martin Kümmel ST-ECF. Overview. WFC3-IR G102. detector defects. Combined white light + direct image. direct image. 0th order. 1st order. 2nd order. 1014 pixel (full size). WFC3-IR G141. detector defects.
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WFC3 GrismsResults from TV22D Simulations Harald Kuntschner, Jeremy Walsh, Martin Kümmel ST-ECF WFC3 SOC, October 04, 2007
Overview WFC3 SOC, October 04, 2007
WFC3-IR G102 detector defects Combined white light + direct image direct image 0th order 1st order 2nd order 1014 pixel (full size) WFC3 SOC, October 04, 2007
WFC3-IR G141 detector defects Combined white light + direct image direct image 0th order 1st order 2nd order 3rd order 1014 pixel (full size) WFC3 SOC, October 04, 2007
WFC3-UV G280 Combined white light + direct image 0th order 1st order -1st order Direct image 4096 pixel (full size) WFC3 SOC, October 04, 2007
WFC3-UV G280 Combined monochromator steps 0th order +1st -1st +2st -2st 4096 pixel (full size) WFC3 SOC, October 04, 2007
WFC3-UV G280 • +8 to -8 orders visible • Heavy order overlap for > +2 order • Order overlap in y-direction between +1st and +2nd beyond ~380nm +8 +7 +6 +5 +4 +3 +2 +1 0 -1 -2 -3 -4 -5 -6 -7 -8 WFC3 SOC, October 04, 2007
WFC3-IR G102 Throughput • 1st order • Peak efficiency of ~30% at 960 - 1120nm • Good sensitivity range: 840 - 1140nm • 2nd order • Efficiency < 5% • 0th order • Efficiency < 1.5% WFC3 SOC, October 04, 2007
WFC3-IR G102 aperture corrections • Aperture corrections are largely wavelength independent • 95% flux within ~10 pixel aperture WFC3 SOC, October 04, 2007
WFC3-IR G141 Throughput • 1st order • Peak efficiency of ~40% at 1420 - 1640nm • Good sensitivity range: 1120 - 1660nm • 2nd order • Efficiency < 6% • 0th order • Efficiency < 1.5% WFC3 SOC, October 04, 2007
WFC3-IR G141 aperture corrections • Aperture corrections are largely wavelength independent • 95% flux within ~12 pixel aperture WFC3 SOC, October 04, 2007
WFC3-UV G280 Throughput • 1st order • Peak efficiency of 24% at 240nm • Good sensitivity range: 200 - 330nm • 2nd order • Efficiency < 2% • 0th order • Efficiency equal to first order at 330nm and rising! WFC3 SOC, October 04, 2007
WFC3-UV G280 Throughput • Higher order efficiencies are at the ~0.1% level WFC3 SOC, October 04, 2007
WFC3-IR G141 trace • Linear trace solutions with rms < 0.05 pixel • f(X-Xref) = 0.0074 * (X-Xref) + 1.1 WFC3 SOC, October 04, 2007
WFC3-IR G1412-dim trace solution central trace: f(X-Xref) = 0.0074 * (X-Xref) + 1.1 Offset = f(X,Y) rms < 0.2 pixel Slope = f(X,Y) WFC3 SOC, October 04, 2007
WFC3-IR G141 dispersion • Linear dispersion solutions with rms < 1 Å • f(X) [Å] = 46.9 * (X) + 8950 * Data points omitted in fit due to wavelength shift caused by steep sensitivity decline WFC3 SOC, October 04, 2007
WFC3-IR G1412-dim dispersion solution central dispersion solution: f(X’) [Å] = 46.9 * (X’) + 8950 Offset = f(X,Y) units=Å rms < 0.1 pixel Dispersion = f(X,Y) units=Å WFC3 SOC, October 04, 2007
WFC3-IR G1022-dim disp solution central dispersion solution: f(X) [Å] = 24.6 * (X) + 6376 Offset = f(X’,Y’) units=Å rms < 0.1 pixel Dispersion = f(X’,Y’) units=Å WFC3 SOC, October 04, 2007
WFC3-IR PSF Moffat Gaussian Gaussian FWHM = 2.3 pixel Moffat FWHM = 1.9 pixel; beta=1.08 Gaussian FWHM = 2.7 pixel Moffat FWHM = 2.3 pixel; beta=1.14 WFC3 SOC, October 04, 2007
WFC3-UV PSF 300-400 nm 230-260 nm Moffat Gaussian Gaussian FWHM = 3.4 pixel Moffat FWHM = 2.9 pixel; beta=1.4 Gaussian FWHM = 3.8 pixel Moffat FWHM = 3.3 pixel; beta=1.5 WFC3 SOC, October 04, 2007
WFC3-UV G280 Trace 5th order polynomial fits +2 order +1 order -1 order 200nm 200nm 530nm 200nm 530nm 530nm WFC3 SOC, October 04, 2007
WFC3-UV G280 dispersion +1 order • 1st order polynomial fit to visualize the dispersion function • 4th order polynomial needed to achieve good fit (rms ~ 0.15 pixel) • ~13 Å per pixel WFC3 SOC, October 04, 2007