Imager CCD nonlinearity
We designate CCDs using the filter (which corresponds to the row) and
column. For example, the g4 CCD is the CCD in the fourth column in the row
covered by the g filter. The nonlinearity plots below are grouped by filter.
In these plots the filled points belong to amplifier 0, the empty ones to
amplifier 1 (if applicable). The Amplifier 1 fits are dashed. The vertical
dotted line is the adopted saturation level for that device; points to the
right of this line are ignored in the fits.
g
r
i
z
The fits shown were to the function::
where
and
are fitted quantities, and
= 0 |
for x < 1 |
= log10(x) |
for x > 1. |
This function represents the nonlinearity in these CCDs well.
The table below shows the the fitting parameters:
chip name |
amplifier |
|
ct |
% error in slope at small count |
max % error at saturation |
rms % deviation over the whole range |
error in the fit to Signal/Count |
|
number of fitted points |
(f/l)-1, the deviation from unity of the fitted countrate
from the countrate measured from the lowest exposure two points in
the data |
change in sensitivity from the beginning of the measuring sequence
to the end measured by comparing the low-exposure frames taken at the
beginning and those taken at the end |
dark level, measured with the camera shutters open but the
monochromator shutter closed for the equivalent of a zero second
monochromator exposure |
g1 |
0 |
-0.0037 |
1820 |
0.1 |
-0.4 |
0.17 |
0.0004 |
1.6 |
11 |
-0.0001 |
-0.002 |
1598.1 |
g2 |
0 |
-0.0050 |
1349 |
0.2 |
-0.6 |
0.26 |
0.0010 |
5.8 |
13 |
0.0000 |
0.002 |
1116.1 |
g2 |
1 |
-0.0238 |
1380 |
0.9 |
-2.8 |
1.25 |
0.0010 |
4.6 |
15 |
0.0001 |
-0.001 |
1103.9 |
g3 |
0 |
-0.0353 |
2818 |
0.9 |
-3.5 |
1.41 |
0.0011 |
7.2 |
12 |
0.0005 |
0.002 |
1147.4 |
g3 |
1 |
-0.0097 |
2951 |
0.2 |
-1.0 |
0.38 |
0.0004 |
1.5 |
12 |
0.0002 |
0.001 |
1142.5 |
g4 |
0 |
-0.0149 |
4786 |
0.3 |
-1.3 |
0.46 |
0.0004 |
1.4 |
12 |
0.0001 |
0.008 |
1251.5 |
g4 |
1 |
-0.0119 |
2818 |
0.3 |
-1.2 |
0.47 |
0.0003 |
0.9 |
12 |
0.0000 |
0.001 |
1238.8 |
g5 |
0 |
-0.0129 |
2399 |
0.4 |
-1.3 |
0.55 |
0.0005 |
1.7 |
13 |
0.0001 |
0.004 |
1203.8 |
g5 |
1 |
-0.0071 |
1175 |
0.3 |
-0.9 |
0.39 |
0.0006 |
2.4 |
12 |
0.0000 |
0.001 |
1192.7 |
g6 |
0 |
-0.0208 |
4677 |
0.4 |
-1.8 |
0.65 |
0.0006 |
2.4 |
11 |
0.0003 |
0.009 |
1229.7 |
g6 |
1 |
-0.0221 |
3388 |
0.5 |
-2.1 |
0.81 |
0.0007 |
3.6 |
11 |
0.0002 |
0.002 |
1216.6 |
i1 |
0 |
-0.0176 |
4677 |
0.5 |
-1.4 |
0.61 |
0.0014 |
27.9 |
11 |
-0.0011 |
0.003 |
1190.4 |
i1 |
1 |
-0.0150 |
4365 |
0.4 |
-1.2 |
0.54 |
0.0012 |
14.9 |
11 |
-0.0009 |
0.003 |
1184.6 |
i2 |
0 |
-0.0274 |
2630 |
1.1 |
-2.4 |
1.21 |
0.0007 |
4.4 |
13 |
-0.0000 |
0.005 |
1183.5 |
i2 |
1 |
-0.0110 |
5888 |
0.2 |
-0.8 |
0.34 |
0.0005 |
3.2 |
13 |
-0.0004 |
0.006 |
1176.4 |
i3 |
0 |
-0.0126 |
3715 |
0.4 |
-1.0 |
0.48 |
0.0002 |
0.7 |
13 |
-0.0001 |
0.004 |
1181.4 |
i3 |
1 |
-0.0146 |
3467 |
0.5 |
-1.2 |
0.58 |
0.0006 |
3.8 |
13 |
-0.0003 |
-0.000 |
1175.7 |
i4 |
0 |
-0.0359 |
3236 |
1.3 |
-3.0 |
1.47 |
0.0008 |
8.3 |
12 |
0.0004 |
0.005 |
1063.3 |
i4 |
1 |
-0.0111 |
4467 |
0.3 |
-0.9 |
0.39 |
0.0007 |
7.6 |
12 |
0.0001 |
0.005 |
1055.8 |
i5 |
0 |
-0.0243 |
2188 |
1.1 |
-2.2 |
1.14 |
0.0004 |
6.3 |
11 |
0.0001 |
0.004 |
1890.1 |
i6 |
0 |
-0.0166 |
3802 |
0.5 |
-1.3 |
0.63 |
0.0007 |
8.3 |
12 |
0.0004 |
0.003 |
1090.8 |
i6 |
1 |
-0.0329 |
3311 |
1.2 |
-2.8 |
1.33 |
0.0007 |
7.6 |
12 |
0.0003 |
-0.002 |
1089.4 |
r1 |
0 |
-0.0075 |
1096 |
0.4 |
-0.8 |
0.43 |
0.0004 |
3.0 |
11 |
-0.0002 |
-0.005 |
1787.1 |
r2 |
0 |
-0.0371 |
3802 |
0.9 |
-3.3 |
1.36 |
0.0008 |
7.7 |
11 |
0.0001 |
0.004 |
1045.6 |
r2 |
1 |
-0.0316 |
3236 |
0.9 |
-2.9 |
1.25 |
0.0009 |
8.8 |
11 |
0.0004 |
0.005 |
1039.7 |
r3 |
0 |
-0.0285 |
3802 |
0.7 |
-2.5 |
1.04 |
0.0006 |
10.5 |
10 |
0.0001 |
0.012 |
1834.3 |
r4 |
0 |
-0.0063 |
6761 |
0.1 |
-0.5 |
0.17 |
0.0005 |
4.0 |
11 |
-0.0005 |
0.005 |
1103.0 |
r4 |
1 |
-0.0349 |
4169 |
0.8 |
-3.0 |
1.22 |
0.0007 |
4.7 |
11 |
0.0003 |
0.005 |
1090.0 |
r5 |
0 |
-0.0374 |
4677 |
0.8 |
-3.1 |
1.24 |
0.0005 |
3.4 |
10 |
0.0002 |
0.007 |
1144.9 |
r5 |
1 |
-0.0400 |
4266 |
0.9 |
-3.4 |
1.39 |
0.0006 |
5.5 |
10 |
0.0005 |
0.004 |
1134.4 |
r6 |
0 |
-0.0100 |
4571 |
0.2 |
-0.8 |
0.33 |
0.0004 |
3.1 |
11 |
-0.0003 |
0.006 |
1223.3 |
r6 |
1 |
-0.0069 |
2692 |
0.2 |
-0.7 |
0.29 |
0.0003 |
0.5 |
11 |
-0.0001 |
0.005 |
1217.6 |
u1 |
0 |
-0.0120 |
4571 |
0.2 |
-1.1 |
0.36 |
0.0005 |
0.7 |
14 |
0.0000 |
0.003 |
1111.2 |
u1 |
1 |
-0.0097 |
977 |
0.4 |
-1.3 |
0.55 |
0.0006 |
1.2 |
14 |
0.0002 |
0.004 |
1098.7 |
u2 |
0 |
-0.0549 |
10233 |
0.4 |
-3.4 |
0.96 |
0.0011 |
3.9 |
14 |
0.0001 |
0.001 |
2769.9 |
u2 |
1 |
-0.0149 |
6761 |
0.2 |
-1.1 |
0.36 |
0.0007 |
1.6 |
14 |
0.0002 |
0.000 |
2769.5 |
u3 |
0 |
-0.0088 |
1175 |
0.3 |
-1.1 |
0.47 |
0.0006 |
1.3 |
14 |
0.0001 |
0.002 |
1234.3 |
u3 |
1 |
-0.0049 |
1950 |
0.1 |
-0.6 |
0.22 |
0.0002 |
0.2 |
14 |
0.0001 |
0.001 |
1224.7 |
u4 |
0 |
-0.0088 |
575 |
0.5 |
-1.2 |
0.58 |
0.0004 |
0.9 |
14 |
-0.0006 |
-0.000 |
1320.0 |
u5 |
0 |
-0.0027 |
1698 |
0.1 |
-0.3 |
0.13 |
0.0006 |
1.3 |
14 |
0.0002 |
-0.000 |
1158.0 |
u5 |
1 |
-0.0019 |
1380 |
0.1 |
-0.2 |
0.10 |
0.0004 |
0.3 |
14 |
0.0001 |
0.002 |
1130.6 |
u6 |
0 |
-0.0261 |
3162 |
0.5 |
-2.6 |
0.96 |
0.0008 |
4.7 |
14 |
0.0003 |
0.001 |
1299.5 |
z1 |
0 |
-0.0156 |
5370 |
0.4 |
-1.1 |
0.50 |
0.0004 |
1.4 |
12 |
-0.0002 |
0.012 |
1147.3 |
z1 |
1 |
-0.0134 |
4786 |
0.3 |
-1.0 |
0.46 |
0.0006 |
3.6 |
12 |
-0.0001 |
0.011 |
1156.0 |
z2 |
0 |
-0.0114 |
5370 |
0.3 |
-0.8 |
0.37 |
0.0004 |
1.7 |
13 |
-0.0000 |
0.003 |
1065.1 |
z2 |
1 |
-0.0140 |
6918 |
0.3 |
-0.9 |
0.39 |
0.0004 |
2.1 |
13 |
0.0002 |
0.003 |
1061.2 |
z3 |
0 |
-0.0136 |
6918 |
0.3 |
-0.9 |
0.38 |
0.0001 |
0.1 |
11 |
-0.0001 |
0.006 |
1047.8 |
z3 |
1 |
-0.0093 |
6918 |
0.2 |
-0.6 |
0.26 |
0.0005 |
2.2 |
11 |
-0.0002 |
0.005 |
1046.5 |
z4 |
0 |
-0.0398 |
5623 |
0.9 |
-2.9 |
1.26 |
0.0012 |
9.4 |
11 |
0.0003 |
0.009 |
1066.3 |
z4 |
1 |
-0.0103 |
7586 |
0.2 |
-0.7 |
0.27 |
0.0006 |
3.2 |
11 |
-0.0002 |
0.006 |
1064.1 |
z5 |
0 |
-0.0151 |
6026 |
0.3 |
-1.1 |
0.45 |
0.0004 |
1.4 |
10 |
0.0000 |
0.004 |
1066.9 |
z5 |
1 |
-0.0151 |
5754 |
0.3 |
-1.1 |
0.47 |
0.0003 |
0.9 |
10 |
0.0001 |
0.004 |
1063.3 |
z6 |
0 |
-0.0148 |
6310 |
0.3 |
-1.0 |
0.43 |
0.0005 |
3.1 |
11 |
0.0001 |
0.007 |
1048.3 |
z6 |
1 |
-0.0359 |
4571 |
1.0 |
-2.8 |
1.26 |
0.0011 |
13.3 |
11 |
0.0005 |
0.006 |
1054.9 |
|