# 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 z Response Function 141 Points # # lam respt resbig resnoa xatm 7730 0.0000 0.0000 0.0000 0.9602 7755 0.0000 0.0000 0.0000 0.9615 7780 0.0001 0.0001 0.0001 0.9605 7805 0.0001 0.0001 0.0001 0.9583 7830 0.0001 0.0001 0.0001 0.9559 7855 0.0002 0.0002 0.0002 0.9541 7880 0.0002 0.0002 0.0002 0.9541 7905 0.0003 0.0003 0.0003 0.9567 7930 0.0005 0.0005 0.0005 0.9622 7955 0.0007 0.0007 0.0007 0.9692 7980 0.0011 0.0011 0.0011 0.9762 8005 0.0017 0.0017 0.0017 0.9814 8030 0.0027 0.0027 0.0027 0.9833 8055 0.0040 0.0040 0.0040 0.9801 8080 0.0057 0.0057 0.0058 0.9702 8105 0.0079 0.0079 0.0082 0.9524 8130 0.0106 0.0106 0.0114 0.9285 8155 0.0139 0.0139 0.0155 0.9075 8180 0.0178 0.0178 0.0202 0.8931 8205 0.0222 0.0222 0.0255 0.8853 8230 0.0271 0.0271 0.0311 0.8843 8255 0.0324 0.0324 0.0369 0.8902 8280 0.0382 0.0382 0.0428 0.9033 8305 0.0446 0.0446 0.0484 0.9242 8330 0.0511 0.0511 0.0536 0.9483 8355 0.0564 0.0564 0.0583 0.9591 8380 0.0603 0.0603 0.0625 0.9576 8405 0.0637 0.0637 0.0661 0.9567 8430 0.0667 0.0667 0.0693 0.9564 8455 0.0694 0.0694 0.0720 0.9565 8480 0.0717 0.0717 0.0744 0.9569 8505 0.0736 0.0736 0.0763 0.9576 8530 0.0752 0.0752 0.0779 0.9584 8555 0.0765 0.0765 0.0792 0.9592 8580 0.0775 0.0775 0.0801 0.9598 8605 0.0782 0.0782 0.0808 0.9602 8630 0.0786 0.0786 0.0812 0.9603 8655 0.0787 0.0787 0.0813 0.9599 8680 0.0785 0.0785 0.0812 0.9593 8705 0.0780 0.0780 0.0807 0.9586 8730 0.0772 0.0772 0.0801 0.9578 8755 0.0763 0.0763 0.0791 0.9571 8780 0.0751 0.0751 0.0779 0.9567 8805 0.0738 0.0738 0.0766 0.9566 8830 0.0723 0.0723 0.0750 0.9571 8855 0.0708 0.0708 0.0734 0.9582 8880 0.0693 0.0693 0.0716 0.9600 8905 0.0674 0.0674 0.0698 0.9591 8930 0.0632 0.0632 0.0679 0.9314 8955 0.0581 0.0581 0.0661 0.8923 8980 0.0543 0.0543 0.0642 0.8648 9005 0.0526 0.0526 0.0624 0.8633 9030 0.0523 0.0523 0.0607 0.8787 9055 0.0522 0.0522 0.0590 0.8961 9080 0.0512 0.0512 0.0574 0.9020 9105 0.0496 0.0496 0.0559 0.8980 9130 0.0481 0.0481 0.0546 0.8931 9155 0.0473 0.0473 0.0535 0.8962 9180 0.0476 0.0476 0.0524 0.9138 9205 0.0482 0.0482 0.0515 0.9352 9230 0.0476 0.0476 0.0505 0.9407 9255 0.0447 0.0447 0.0496 0.9103 9280 0.0391 0.0391 0.0485 0.8345 9305 0.0329 0.0329 0.0474 0.7441 9330 0.0283 0.0283 0.0462 0.6752 9355 0.0264 0.0264 0.0450 0.6524 9380 0.0271 0.0271 0.0438 0.6794 9405 0.0283 0.0283 0.0426 0.7178 9430 0.0275 0.0275 0.0415 0.7184 9455 0.0254 0.0254 0.0404 0.6897 9480 0.0252 0.0252 0.0393 0.7003 9505 0.0256 0.0256 0.0383 0.7214 9530 0.0246 0.0246 0.0373 0.7147 9555 0.0244 0.0244 0.0363 0.7251 9580 0.0252 0.0252 0.0353 0.7594 9605 0.0258 0.0258 0.0342 0.7923 9630 0.0265 0.0265 0.0331 0.8302 9655 0.0274 0.0274 0.0319 0.8766 9680 0.0279 0.0279 0.0307 0.9150 9705 0.0271 0.0271 0.0294 0.9253 9730 0.0252 0.0252 0.0280 0.9059 9755 0.0236 0.0236 0.0267 0.8947 9780 0.0227 0.0227 0.0253 0.9045 9805 0.0222 0.0222 0.0240 0.9262 9830 0.0216 0.0216 0.0227 0.9500 9855 0.0208 0.0208 0.0213 0.9652 9880 0.0196 0.0196 0.0201 0.9656 9905 0.0183 0.0183 0.0188 0.9642 9930 0.0171 0.0171 0.0176 0.9630 9955 0.0160 0.0160 0.0165 0.9618 9980 0.0149 0.0149 0.0153 0.9607 10005 0.0138 0.0138 0.0143 0.9597 10030 0.0128 0.0128 0.0132 0.9588 10055 0.0118 0.0118 0.0122 0.9579 10080 0.0108 0.0108 0.0112 0.9572 10105 0.0099 0.0099 0.0103 0.9565 10130 0.0091 0.0091 0.0094 0.9559 10155 0.0083 0.0083 0.0086 0.9553 10180 0.0075 0.0075 0.0078 0.9549 10205 0.0068 0.0068 0.0071 0.9545 10230 0.0061 0.0061 0.0064 0.9541 10255 0.0055 0.0055 0.0058 0.9539 10280 0.0050 0.0050 0.0052 0.9537 10305 0.0045 0.0045 0.0047 0.9535 10330 0.0041 0.0041 0.0042 0.9534 10355 0.0037 0.0037 0.0038 0.9534 10380 0.0033 0.0033 0.0035 0.9534 10405 0.0030 0.0030 0.0031 0.9535 10430 0.0027 0.0027 0.0028 0.9536 10455 0.0025 0.0025 0.0026 0.9537 10480 0.0023 0.0023 0.0024 0.9539 10505 0.0021 0.0021 0.0022 0.9541 10530 0.0019 0.0019 0.0020 0.9544 10555 0.0018 0.0018 0.0019 0.9547 10580 0.0017 0.0017 0.0018 0.9551 10605 0.0016 0.0016 0.0016 0.9554 10630 0.0015 0.0015 0.0015 0.9558 10655 0.0014 0.0014 0.0014 0.9563 10680 0.0013 0.0013 0.0013 0.9567 10705 0.0012 0.0012 0.0012 0.9572 10730 0.0011 0.0011 0.0011 0.9577 10755 0.0010 0.0010 0.0010 0.9582 10780 0.0009 0.0009 0.0009 0.9587 10805 0.0008 0.0008 0.0008 0.9593 10830 0.0008 0.0008 0.0008 0.9598 10855 0.0007 0.0007 0.0007 0.9604 10880 0.0006 0.0006 0.0007 0.9609 10905 0.0006 0.0006 0.0006 0.9615 10930 0.0006 0.0006 0.0006 0.9621 10955 0.0005 0.0005 0.0005 0.9626 10980 0.0005 0.0005 0.0005 0.9632 11005 0.0004 0.0004 0.0004 0.9638 11030 0.0004 0.0004 0.0004 0.9643 11055 0.0003 0.0003 0.0003 0.9648 11080 0.0003 0.0003 0.0003 0.9654 11105 0.0002 0.0002 0.0002 0.9659 11130 0.0002 0.0002 0.0002 0.9664 11155 0.0001 0.0001 0.0001 0.9669 11180 0.0001 0.0001 0.0001 0.9673 11205 0.0000 0.0000 0.0000 0.9677 11230 0.0000 0.0000 0.0000 0.9682