# 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 r Response Function 75 Points # # lam respt resbig resnoa xatm 5380 0.0000 0.0000 0.0000 0.8869 5405 0.0014 0.0014 0.0016 0.8877 5430 0.0099 0.0099 0.0113 0.8885 5455 0.0259 0.0260 0.0297 0.8891 5480 0.0497 0.0498 0.0568 0.8897 5505 0.0807 0.0809 0.0923 0.8902 5530 0.1186 0.1190 0.1356 0.8907 5555 0.1625 0.1630 0.1856 0.8911 5580 0.2093 0.2100 0.2390 0.8914 5605 0.2555 0.2564 0.2917 0.8917 5630 0.2975 0.2986 0.3395 0.8920 5655 0.3326 0.3339 0.3794 0.8923 5680 0.3609 0.3623 0.4116 0.8926 5705 0.3834 0.3849 0.4371 0.8929 5730 0.4010 0.4027 0.4570 0.8933 5755 0.4147 0.4165 0.4723 0.8938 5780 0.4253 0.4271 0.4839 0.8945 5805 0.4333 0.4353 0.4925 0.8952 5830 0.4395 0.4416 0.4990 0.8962 5855 0.4446 0.4467 0.5040 0.8973 5880 0.4489 0.4511 0.5080 0.8986 5905 0.4527 0.4550 0.5112 0.9001 5930 0.4563 0.4587 0.5141 0.9018 5955 0.4599 0.4624 0.5169 0.9037 5980 0.4634 0.4660 0.5194 0.9057 6005 0.4665 0.4692 0.5213 0.9079 6030 0.4689 0.4716 0.5222 0.9103 6055 0.4703 0.4731 0.5220 0.9128 6080 0.4711 0.4740 0.5212 0.9153 6105 0.4717 0.4747 0.5202 0.9177 6130 0.4727 0.4758 0.5197 0.9199 6155 0.4744 0.4776 0.5202 0.9220 6180 0.4767 0.4800 0.5215 0.9238 6205 0.4792 0.4827 0.5233 0.9253 6230 0.4819 0.4854 0.5254 0.9265 6255 0.4844 0.4881 0.5275 0.9275 6280 0.4867 0.4905 0.5294 0.9285 6305 0.4887 0.4926 0.5310 0.9294 6330 0.4902 0.4942 0.5319 0.9305 6355 0.4909 0.4951 0.5320 0.9316 6380 0.4912 0.4955 0.5316 0.9327 6405 0.4912 0.4956 0.5310 0.9337 6430 0.4912 0.4958 0.5305 0.9346 6455 0.4914 0.4961 0.5302 0.9354 6480 0.4915 0.4964 0.5299 0.9363 6505 0.4912 0.4962 0.5290 0.9373 6530 0.4901 0.4953 0.5271 0.9385 6555 0.4878 0.4931 0.5241 0.9395 6580 0.4852 0.4906 0.5211 0.9400 6605 0.4818 0.4873 0.5176 0.9398 6630 0.4697 0.4752 0.5057 0.9386 6655 0.4421 0.4474 0.4775 0.9366 6680 0.4009 0.4059 0.4341 0.9349 6705 0.3499 0.3544 0.3792 0.9345 6730 0.2924 0.2963 0.3162 0.9366 6755 0.2318 0.2350 0.2488 0.9421 6780 0.1715 0.1739 0.1824 0.9492 6805 0.1152 0.1168 0.1225 0.9494 6830 0.0687 0.0697 0.0747 0.9334 6855 0.0380 0.0386 0.0430 0.9057 6880 0.0212 0.0215 0.0247 0.8862 6905 0.0134 0.0136 0.0155 0.8893 6930 0.0099 0.0101 0.0112 0.9083 6955 0.0076 0.0077 0.0083 0.9311 6980 0.0055 0.0056 0.0059 0.9450 7005 0.0039 0.0039 0.0041 0.9464 7030 0.0027 0.0028 0.0029 0.9561 7055 0.0020 0.0020 0.0021 0.9709 7080 0.0015 0.0016 0.0016 0.9826 7105 0.0012 0.0013 0.0013 0.9827 7130 0.0010 0.0010 0.0010 0.9629 7155 0.0007 0.0007 0.0008 0.9192 7180 0.0004 0.0004 0.0005 0.8849 7205 0.0002 0.0002 0.0002 0.8974 7230 0.0000 0.0000 0.0000 0.9182