# The following file is from Jim Gunn, from June 2001. It should be # self-explanatory; for most purposes, you will want to use the second # column. Consider this file preliminary. # # These filter curves have been used to calculate the effective # wavelengths and the qtdl/l (see Chapter 8 of the Black Book) of the # filters; the values are: # # u 3551 0.0171 # g 4686 0.0893 # r 6166 0.0886 # i 7480 0.0591 # z 8932 0.0099 # # Table Caption For Response Functions # # The first column is the wavelength in \AAngstroms. The second column # (respt) is the quantum efficiency on the sky looking through 1.3 # airmasses at APO for a point source. The third column (resbig) is the # QE under these conditions for very large sources (size greater than # about 80 pixels) for which the infrared scattering is negligible. The # only filters for which the infrared scattering has any effect are r and # i; the scattering in the bluer chips is negligible, and the z chips are # not thinned and the phenomenon does not exist. The fourth column # (resnoa) is the response of the third column with {\it no} atmosphere, # and the fifth column is the assumed atmospheric transparency at {\it # one} airmass at APO. The tables were constructed using monochromator # illumination of the camera with a bandpass of about 100 \AA, sampled for # the u filter at 50 \AA intervals and for the others at 100 \AA # intervals. These measurements were compared with measured responses of # the component filters and detectors and three additional points were # interpolated using these data, two at the extreme toes and one # additional (in g, r, and i) at the point of the beginning of the sharp # cutoff of the shortpass interference filter. These points are necessary # in order to make spline interpolation of the response data well-behaved. # These spline-interpolated response data were then multiplied by measured # aluminum reflectivities and scaled atmospheric transmission to produce # the tables below. The overall normalization is somewhat uncertain, # but this uncertainty does not affect the shapes. Note, however, that # there has been no attempt to remove the finite resolution of the # monochromator measurements. These tables are the {\it averages} of the # responses for all six of the camera chips with a given filter. The # responses are in general very similar except in the z band, where the # nonuniformity of the infrared rolloff, presumably associated with # varying thickness of the epitaxial layer or perhaps the gate structures # in these thick devices, introduces variations in the effective wavelengths # of the filters of order 100 \AA. We are currently working on better # response functions and will present them when they become available, but # these will suffice for most applications. In all cases the first point # is a measured point, so the grid of wavelengths at which measurements # exist is a subset of the wavelength lists here. # # SDSS Camera g Response Function 89 Points # # lam respt resbig resnoa xatm 3630 0.0000 0.0000 0.0000 0.6476 3655 0.0003 0.0003 0.0005 0.6553 3680 0.0008 0.0008 0.0013 0.6631 3705 0.0013 0.0013 0.0022 0.6702 3730 0.0019 0.0019 0.0030 0.6763 3755 0.0024 0.0024 0.0039 0.6815 3780 0.0034 0.0034 0.0055 0.6863 3805 0.0055 0.0055 0.0087 0.6912 3830 0.0103 0.0103 0.0162 0.6965 3855 0.0194 0.0194 0.0301 0.7023 3880 0.0326 0.0326 0.0500 0.7088 3905 0.0492 0.0492 0.0745 0.7158 3930 0.0686 0.0686 0.1024 0.7235 3955 0.0900 0.0900 0.1324 0.7315 3980 0.1123 0.1123 0.1629 0.7393 4005 0.1342 0.1342 0.1924 0.7464 4030 0.1545 0.1545 0.2191 0.7526 4055 0.1722 0.1722 0.2419 0.7581 4080 0.1873 0.1873 0.2609 0.7631 4105 0.2003 0.2003 0.2767 0.7680 4130 0.2116 0.2116 0.2899 0.7727 4155 0.2214 0.2214 0.3010 0.7774 4180 0.2301 0.2301 0.3105 0.7820 4205 0.2378 0.2378 0.3186 0.7862 4230 0.2448 0.2448 0.3258 0.7902 4255 0.2513 0.2513 0.3324 0.7940 4280 0.2574 0.2574 0.3385 0.7976 4305 0.2633 0.2633 0.3442 0.8013 4330 0.2691 0.2691 0.3496 0.8049 4355 0.2747 0.2747 0.3548 0.8087 4380 0.2801 0.2801 0.3596 0.8124 4405 0.2852 0.2852 0.3640 0.8161 4430 0.2899 0.2899 0.3678 0.8199 4455 0.2940 0.2940 0.3709 0.8235 4480 0.2979 0.2979 0.3736 0.8271 4505 0.3016 0.3016 0.3763 0.8305 4530 0.3055 0.3055 0.3792 0.8337 4555 0.3097 0.3097 0.3827 0.8368 4580 0.3141 0.3141 0.3863 0.8397 4605 0.3184 0.3184 0.3899 0.8425 4630 0.3224 0.3224 0.3931 0.8453 4655 0.3257 0.3257 0.3955 0.8480 4680 0.3284 0.3284 0.3973 0.8505 4705 0.3307 0.3307 0.3986 0.8528 4730 0.3327 0.3327 0.3997 0.8549 4755 0.3346 0.3346 0.4008 0.8568 4780 0.3364 0.3364 0.4019 0.8587 4805 0.3383 0.3383 0.4030 0.8606 4830 0.3403 0.3403 0.4043 0.8625 4855 0.3425 0.3425 0.4057 0.8643 4880 0.3448 0.3448 0.4073 0.8661 4905 0.3472 0.3472 0.4091 0.8678 4930 0.3495 0.3495 0.4110 0.8693 4955 0.3519 0.3519 0.4129 0.8706 4980 0.3541 0.3541 0.4147 0.8719 5005 0.3562 0.3562 0.4165 0.8730 5030 0.3581 0.3581 0.4181 0.8740 5055 0.3597 0.3597 0.4194 0.8750 5080 0.3609 0.3609 0.4201 0.8759 5105 0.3613 0.3613 0.4201 0.8768 5130 0.3609 0.3609 0.4191 0.8777 5155 0.3595 0.3595 0.4169 0.8785 5180 0.3581 0.3581 0.4147 0.8794 5205 0.3558 0.3558 0.4115 0.8803 5230 0.3452 0.3452 0.3988 0.8813 5255 0.3194 0.3194 0.3684 0.8822 5280 0.2807 0.2807 0.3233 0.8832 5305 0.2339 0.2339 0.2690 0.8842 5330 0.1839 0.1839 0.2112 0.8852 5355 0.1352 0.1352 0.1550 0.8861 5380 0.0911 0.0911 0.1043 0.8869 5405 0.0548 0.0548 0.0627 0.8877 5430 0.0295 0.0295 0.0337 0.8885 5455 0.0166 0.0166 0.0190 0.8891 5480 0.0112 0.0112 0.0128 0.8897 5505 0.0077 0.0077 0.0087 0.8902 5530 0.0050 0.0050 0.0057 0.8907 5555 0.0032 0.0032 0.0037 0.8911 5580 0.0021 0.0021 0.0024 0.8914 5605 0.0015 0.0015 0.0017 0.8917 5630 0.0012 0.0012 0.0014 0.8920 5655 0.0010 0.0010 0.0012 0.8923 5680 0.0009 0.0009 0.0010 0.8926 5705 0.0008 0.0008 0.0009 0.8929 5730 0.0006 0.0006 0.0007 0.8933 5755 0.0005 0.0005 0.0005 0.8938 5780 0.0003 0.0003 0.0003 0.8945 5805 0.0001 0.0001 0.0001 0.8952 5830 0.0000 0.0000 0.0000 0.8962