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Near Infrared Camera and Multi-Object Spectrometer Instrument Handbook for Cycle 17 > Appendix A: ImagingReference Material

Appendix A:
Imaging
Reference Material
This appendix provides basic throughput information and plots for the imaging and polarimetric filters. The corresponding information for the grism elements is provided in Chapter 5. It is important to note that the information provided here is approximate. The precise values will change as each CDBS update provides more accurate data. Users should follow the instructions below to generate their own data using in STSDAS while keeping in mind that their calculated values should be close to those provided here.
The spectral characteristics of the NICMOS flight filters were measured at cryogenic temperature and normal incidence at Ball Aerospace. All filters had their spectral transmission measured from 0.5 to 2.7 microns with a step of 0.001 microns. For each filter, we provide the following information:
A plot of the total system throughput, which convolves the filter transmission curve with the OTA, the NICMOS foreoptics and the predicted detector's response under NCS operations.
A listing of the central, mean, and peak wavelengths, of the wavelength range, filter width, transmission peak, and the fraction of the PSF contained in one pixel (assuming the source is centered on the pixel) is also given.
All throughput curves and band parameters in this section were built with the DQE curve corrected to 77.1 K. The values for most of these parameters come directly from the synphot task in STSDAS. The graph (grtbl) and component (cmptbl) tables used for these calculations were:
grtbl = “k511557nm_tmg.fits
cmptbl = “m7t1443mm_tmc.fits
The above tables used for these calculations are available from CDBS at STScI.
The filter transmission curves and OTA and NICMOS optics reflectivities are the ones listed in these files. The only change made relative to these tables is that the nic?_dqe* table for each camera was modified to reflect changes from the reference temperature of each curve to the nominal NCS operating temperature (77.1 K, at the NDWTMP11 Mounting Cup temperature sensor). Based on the NICMOS standard star photometry, each DQE curve + filter transmission curve is correct for the temperature at which the standard star observations were made (NIC1: 61.3 K, NIC2: 61.3 K, NIC3: 62.0 K).
The correction of the original DQE curves were made based on the ratio of the mean value of lamp-flat images taken at the current operating temperature of 77.1 K to flats taken at the above temperatures. The correction factor as a function of wavelength is then multiplied by the original curve to get the new curve. Note that the DQE can vary by factors of 2–3 across each array.
The band parameters correspond to the output of the STSDAS task bandpar where:
 
Central wavelength = PIVWV
Mean wavelength = AVGWV
Peak wavelength = WPEAK
Maximum throughput = TPEAK
These outputs can be easily generated from bandpar. For example the following command generates these outputs for the F160W filter on camera 3:
bandpar nicmos,3,f160w
The FWHM is defined as the intersection between the transmission curve and the half-maximum-transmission value. Since the transmission curve shape is strongly affected by the DQE (particularly for the broad filters), the measured FWHM will change with temperature. This is NOT the FWHM value returned by the bandpar task.
The “Wavelength range” values are just measured by-eye from the throughput curves to serve as a rough estimate.
The “central pixel fraction” is the fraction of the total light from a point source that is contained in the central pixel of the point spread function (PSF). This assumes that the source is centered on a pixel, and that the pixel response function is unity across the pixel. All PSFs were made from TinyTim V6.0, using the following parameters, in each of the filters:
  1.80 mm PAM for NIC1
  0.20 mm PAM for NIC2
default TinyTim V6.0 throughput tables and the G2V source spectrum
Camera 1, Filter F090M
Central wavelength: 0. 90332 μm
Mean wavelength: 0. 90505 μm
Peak wavelength: 0. 91751 μm
Wavelength range: 0.8–1.0 μm
FWHM: 0.1731 μm
Maximum throughput: 8.2466%
Central pixel fraction: 0.123
Figure A.1: F090M Throughput
Camera 1, Filter F095N
Central wavelength: 0.9537 μm
Mean wavelength: 0.9537 μm
Peak wavelength: 0.9564 μm
Wavelength range: 0.949–0.958 μm
FWHM: 0.0093 μm
Maximum throughput: 6.7631%
Central pixel fraction: 0.114
Camera 1, Filter F097N
Central wavelength: 0.9716 μm
Mean wavelength: 0.9716 μm
Peak wavelength: 0.9740 μm
Wavelength range: 0.967–0.977 μm
FWHM: 0.0097 μm
Maximum throughput: 8.0253%
Central pixel fraction: 0.111
Figure A.3: F097N Throughput
Camera 1, Filter F108N
Central wavelength: 1.0816 μm
Mean wavelength: 1.0816 μm
Peak wavelength: 1.0790 μm
Wavelength range: 1.0–1.2 μm
FWHM: 0.0099 μm
Maximum throughput: 9.5904%
Central pixel fraction: 0.094
Camera 1, Filter F110M
Central wavelength: 1.1016 μm
Mean wavelength: 1.1032 μm
Peak wavelength: 1.1295 μm
Wavelength range: 1.0–1.2 μm
FWHM: 0.1982 μm
Maximum throughput: 12.262%
Central pixel fraction: 0.092
Camera 1, Filter F110W
Central wavelength: 1.1220 μm
Mean wavelength: 1.1341 μm
Peak wavelength: 1.3430 μm
Wavelength range: 0.8–1.4 μm
FWHM: 0.5277 μm
Maximum throughput: 15.233%
Central pixel fraction: 0.095
Camera 1, Filter F113N
Central wavelength: 1.1298 μm
Mean wavelength: 1.1298 μm
Peak wavelength: 1.1312 μm
Wavelength range: 1.124–1.135 μm
FWHM: 0.0113 μm
Maximum throughput: 11.162%
Central pixel fraction: 0.088
Camera 1, Filter F140W
Central wavelength: 1.4236 μm
Mean wavelength: 1.4433 μm
Peak wavelength: 1.7769 μm
Wavelength range: 1.0–1.8 μm
FWHM: 0.7509 μm
Maximum throughput: 22.215%
Central pixel fraction: 0.066
Camera 1, Filter F145M
H2O band.
Central wavelength: 1.4546 μm
Mean wavelength: 1.4558 μm
Peak wavelength: 1.5100 μm
Wavelength range: 1.35–1.55 μm
FWHM: 0.1963 μm
Maximum throughput: 18.233%
Central pixel fraction: 0.057
Camera 1, Filter F160W
Central wavelength: 1.6028 μm
Mean wavelength: 1.6071 μm
Peak wavelength: 1.7725 μm
Wavelength range: 1.4–1.8 μm
FWHM: 0.3989 μm
Maximum throughput: 22.395%
Central pixel fraction: 0.049
Camera 1, Filter F164N
Central wavelength: 1.6460 μm
Mean wavelength: 1.6460 μm
Peak wavelength: 1.6476 μm
Wavelength range: 1.636–1.655 μm
FWHM: 0.0173 μm
Maximum throughput: 0.0173%
Central pixel fraction: 0.046
Camera 1, Filter F165M
H2O continuum.
Central wavelength: 1.6478 μm
Mean wavelength: 1.6488 μm
Peak wavelength: 1.7085 μm
Wavelength range: 1.54–1.74 μm
FWHM: 0.1985 μm
Maximum throughput: 22.12%
Central pixel fraction: 0.046
Camera 1, Filter F166N
Central wavelength: 1.6607 μm
Mean wavelength: 1.6607 μm
Peak wavelength: 1.6624 μm
Wavelength range: 1.652–1.668 μm
FWHM: 0.0170 μm
Maximum throughput: 19.895%
Central pixel fraction: 0.045
Camera 1, Filter F170M
Central wavelength: 1.7055 μm
Mean wavelength: 1.7066 μm
Peak wavelength: 1.7885 μm
Wavelength range: 1.6–1.8 μm
FWHM: 0.2025 μm
Maximum throughput: 22.517%
Central pixel fraction: 0.043
Camera 1, Filter F187N
Central wavelength: 1.8748 μm
Mean wavelength: 1.8748 μm
Peak wavelength: 1.8756 μm
Wavelength range: 1.865–1.885 μm
FWHM: 0.0191 μm
Maximum throughput: 21.7%
Central pixel fraction: 0.036
Camera 1, Filter F190N
Paschen α continuum.
Central wavelength: 1.8986 μm
Mean wavelength: 1.8986 μm
Peak wavelength: 1.8942 μm
Wavelength range: 1.890–1.907 μm
FWHM: 0.0178 μm
Maximum throughput: 22.139%
Central pixel fraction: 0.035
Camera 1, Polarizer POL0S
See Table 5.2 for characteristics of
polarizers POL120S and POL240S.
Central wavelength: 1. 0557μm
Mean wavelength: 1.0639 μm
Peak wavelength: 1.1435 μm
Wavelength range: 0.8–1.3
FWHM: 0.4473 μm
Maximum throughput: 5.798%
Central pixel fraction: 0.101
Camera 2, Filter F110W
Central wavelength: 1.1246 μm
Mean wavelength: 1.1364 μm
Peak wavelength: 1.3404 μm
Wavelength range: 0.8–1.4 μm
FWHM: 0.5261 μm
Maximum throughput: 17.141%
Central pixel fraction: 0.235
Camera 2, Filter F160W
Central wavelength: 1.6037 μm
Mean wavelength: 1.6080 μm
Peak wavelength: 1.7720 μm
Wavelength range: 1.4–1.8 μm
FWHM: 0.4010 μm
Maximum throughput: 25.236%
Central pixel fraction: 0.136
Camera 2, Filter F165M
Central wavelength: 1.6511 μm
Mean wavelength: 1.6521 μm
Peak wavelength: 1.7135 μm
Wavelength range: 1.54–1.74 μm
FWHM: 0.1984 μm
Maximum throughput: 25.247%
Central pixel fraction: 0.127
Camera 2, Filter F171M
HCO2 and C2 continuum.
Central wavelength: 1.7211 μm
Mean wavelength: 1.7213 μm
Peak wavelength: 1.7258 μm
Wavelength range: 1.68–1.76 μm
FWHM: 0.0714 μm
Maximum throughput: 24.333%
Central pixel fraction: 0.119
Camera 2, Filter F180M
HCO2 and C2.
Central wavelength: 1.7970 μm
Mean wavelength: 1.7972 μm
Peak wavelength: 1.8132 μm
Wavelength range: 1.76–1.83 μm
FWHM: 0.0686 μm
Maximum throughput: 24.913%
Central pixel fraction: 0.110
Camera 2, Filter F187N
Central wavelength: 1.8740 μm
Mean wavelength: 1.8740 μm
Peak wavelength: 1.8746 μm
Wavelength range: 1.864–1.884 μm
FWHM: 0.0194 μm
Maximum throughput: 24.585%
Central pixel fraction: 0.102
Figure A.23: NIC2 F187N Throughput
Camera 2, Filter F187W
Notes:
Central wavelength: 1.8708 μm
Mean wavelength: 1.8723 μm
Peak wavelength: 1.8930 μm
Wavelength range: 1.75–2.0 μm
FWHM: 0. 2448 μm
Maximum throughput: 24.079%
Central pixel fraction: 0.103
Camera 2, Filter F190N
Paschen α continuum.
Central wavelength: 1.9003 μm
Mean wavelength: 1.9003 μm
Peak wavelength: 1.9004 μm
Wavelength range: 1.892–1.908 μm
FWHM: 0. 0177μm
Maximum throughput: 25.697%
Central pixel fraction: 0.100
Camera 2, Filter F204M
Central wavelength: 2.0353 μm
Mean wavelength: 2.0356 μm
Peak wavelength: 2.0634 μm
Wavelength range: 1.98–2.08 μm
FWHM: 0.1043 μm
Maximum throughput: 28.261%
Central pixel fraction: 0.089
Camera 2, Filter F205W
Central wavelength: 2.0658 μm
Mean wavelength: 2.0738 μm
Peak wavelength: 2.3150 μm
Wavelength range: 1.75–2.35 μm
FWHM: 0.5983 μm
Maximum throughput: 36.53%
Central pixel fraction: 0.090
Camera 2, Filter F207M
Central wavelength: 2.0821 μm
Mean wavelength: 2.0826 μm
Peak wavelength: 2.0672 μm
Wavelength range: 2.01–2.16 μm
FWHM: 0.1524 μm
Maximum throughput: 26.748%
Central pixel fraction: 0.085
Camera 2, Filter F212N
H2 line.
Central wavelength: 2.1213 μm
Mean wavelength: 2.1213 μm
Peak wavelength: 2.1228 μm
Wavelength range: 2.111–2.132 μm
FWHM: 0.0208 μm
Maximum throughput: 27.421%
Central pixel fraction: 0.082
Camera 2, Filter F215N
N2 + Brackett γ continuum.
Central wavelength: 2.1487 μm
Mean wavelength: 2.1487 μm
Peak wavelength: 2.1562 μm
Wavelength range: 2.138–2.158 μm
FWHM: 0.0203 μm
Maximum throughput: 26.771%
Central pixel fraction: 0.081
Camera 2, Filter F216N
Brackett γ line.
Central wavelength: 2.1641 μm
Mean wavelength: 2.1641 μm
Peak wavelength: 2.1668 μm
Wavelength range: 2.154–2.174 μm
FWHM: 0.0212 μm
Maximum throughput: 27.783%
Central pixel fraction: 0.079
Camera 2, Filter F222M
Central wavelength: 2.2177 μm
Mean wavelength: 2.2183 μm
Peak wavelength: 2.1866 μm
Wavelength range: 2.15–2.29 μm
FWHM: 0.1455 μm
Maximum throughput: 28.186%
Central pixel fraction: 0.076
Camera 2, Filter F237M
Central wavelength: 2.3692 μm
Mean wavelength: 2.3697 μm
Peak wavelength: 2.4338 μm
Wavelength range: 2.29–2.44 μm
FWHM: 0.1540 μm
Maximum throughput: 34.756%
Central pixel fraction: 0.067
Camera 2, Polarizer POL0L
See Table 5.2 for characteristics of
POL120L and POL240L.
Central wavelength: 1.9999 μm
Mean wavelength: 2.0009 μm
Peak wavelength: 2.0750 μm
Wavelength range: 1.89–2.1 μm
FWHM: 0.2014 μm
Maximum throughput: 15.546%
Central pixel fraction: 0.092
Camera 3, Filter F108N
Central wavelength: 1.0799 μm
Mean wavelength: 1.0800 μm
Peak wavelength: 1.0776 μm
Wavelength range: 1.075–1.085 μm
FWHM: 0.0100 μm
Maximum throughput: 9.7921%
Central pixel fraction: 0.485
Camera 3, Filter F110W
Central wavelength: 1.1191 μm
Mean wavelength: 1.1316 μm
Peak wavelength: 1.3404 μm
Wavelength range: 0.8–1.4 μm
FWHM: 0.5880 μm
Maximum throughput: 15.336%
Central pixel fraction: 0.496
Camera 3, Filter F113N
Central wavelength: 1.1284 μm
Mean wavelength: 1.1284 μm
Peak wavelength: 1.1316 μm
Wavelength range: 1.122–1.133 μm
FWHM: 0.0114 μm
Maximum throughput: 11.591%
Central pixel fraction: 0.486
Camera 3, Filter F150W
Central wavelength: 1.5332 μm
Mean wavelength: 1.5509 μm
Peak wavelength: 1.7675 μm
Wavelength range: 1.1–1.9 μm
FWHM: 0.7738 μm
Maximum throughput: 24.536%
Central pixel fraction: 0.475
Camera 3, Filter F160W
Central wavelength: 1.6036 μm
Mean wavelength: 1.6079 μm
Peak wavelength: 1.7725 μm
Wavelength range: 1.4–1.8 μm
FWHM: 0.3989 μm
Maximum throughput: 23.465%
Central pixel fraction: 0.474
Camera 3, Filter F164N
Central wavelength: 1.6460 μm
Mean wavelength: 1.6460 μm
Peak wavelength: 1.6476 μm
Wavelength range: 1.637–1.655 μm
FWHM: 0.0173 μm
Maximum throughput: 20.234%
Central pixel fraction: 0.471
Camera 3, Filter F166N
Central wavelength: 1.6583 μm
Mean wavelength: 1.6583 μm
Peak wavelength: 1.6602 μm
Wavelength range: 1.649–1.667 μm
FWHM: 0.0169 μm
Maximum throughput: 20.419%
Central pixel fraction: 0.70
Camera 3, Filter F175W
Central wavelength: 1.805 μm
Mean wavelength: 1.8333 μm
Peak wavelength: 2.2835 μm
Wavelength range: 1.2–2.3 μm
FWHM: 0.9137 μm
Maximum throughput: 31.531%
Central pixel fraction: 0.448
Camera 3, Filter F187N
Paschen α line.
Central wavelength: 1.8748 μm
Mean wavelength: 1.8748 μm
Peak wavelength: 1.8756 μm
Wavelength range: 1.865–1.884 μm
FWHM: 0.0191 μm
Maximum throughput: 22.56%
Central pixel fraction: 0.439
Camera 3, Filter F190N
Paschen α continuum.
Central wavelength: 1.9003 μm
Mean wavelength: 1.9003 μm
Peak wavelength: 1.9004 μm
Wavelength range: 1.892–1.908 μm
FWHM: 0.0178 μm
Maximum throughput: 24.191%
Central pixel fraction: 0.434
Camera 3, Filter F196N
Central wavelength: 1.9639 μm
Mean wavelength: 1.9639 μm
Peak wavelength: 1.9698 μm
Wavelength range: 1.954–1.974 μm
FWHM: 0.0190 μm
Maximum throughput: 24.834%
Central pixel fraction: 0.424
Camera 3, Filter F200N
Central wavelength: 1.9975 μm
Mean wavelength: 1.9975 μm
Peak wavelength: 2.0022 μm
Wavelength range: 1.986–2.007 μm
FWHM: 0.0209 μm
Maximum throughput: 24.012%
Central pixel fraction: 0.418
Camera 3, Filter F212N
H2 line.
Central wavelength: 2.1213 μm
Mean wavelength: 2.1213 μm
Peak wavelength: 2.1228 μm
Wavelength range: 2.111–2.132 μm
FWHM: 0.0208 μm
Maximum throughput: 24.611%
Central pixel fraction: 0.396
Camera 3, Filter F215N
H2 continuum.
Central wavelength: 2.1487 μm
Mean wavelength: 2.1487 μm
Peak wavelength: 2.1562 μm
Wavelength range: 2.138–2.158 μm
FWHM: 0.0202 μm
Maximum throughput: 23.867%
Central pixel fraction: 0.391
Camera 3, Filter F222M
Central wavelength: 2.2174 μm
Mean wavelength: 2.2180 μm
Peak wavelength: 2.1866 μm
Wavelength range: 2.15–2.28 μm
FWHM: 0.1451 μm
Maximum throughput: 25.088%
Central pixel fraction: 0.380
Camera 3, Filter F240M
Central wavelength: 2.3955 μm
Mean wavelength: 2.3963 μm
Peak wavelength: 2.4130 μm
Wavelength range: 2.3–2.5 μm
FWHM: 0.1951 μm
Maximum throughput: 29.697%
Central pixel fraction: 0.349

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