Next: 10.2.3 Noise Models Up: 10.2 Spectral Flux Extraction Previous: 10.2.1 Determination of Echelle-Order

## 10.2.2 Description of Spectral Flux Extraction Process

A boxcar extraction slit running along each order is used to extract the spectral fluxes. The length of the extraction slit (listed in Table 10.2 for the various extraction modes) was chosen on the basis of tests with a large group of images to admit a fixed fraction (98%) of an order's total flux.

This fraction may fluctuate slightly for a given image according to the actual width of its spatial profile, but it is expected to be the same for orders of a given image. The weights of all pixels, including flagged ones, in the boxcar are the same, except for fractional weights of pixels at the ends of the extraction slit. Thus the fluxes are summed along the slit at each wavelength. To obtain the net fluxes, the background fluxes determined by the BCKGRD step are normalized to the extraction slit area and subtracted from the gross spectral flux.

 Order LWP LWR SWP No. Lg. Ext. Sm. Lg. Ext. Sm. Lg. Ext. Sm. 127 5.14 6.24 5.14 5.14 6.24 5.14 126 5.14 6.24 5.14 5.14 6.24 5.14 125 5.14 6.24 5.14 5.14 6.24 5.14 4.72 6.07 4.08 124 5.14 6.24 5.14 5.14 6.24 5.14 4.72 6.07 4.08 123 5.14 6.24 5.14 5.14 6.24 5.14 4.72 6.07 4.08 122 5.14 6.24 5.14 5.14 6.24 5.14 4.72 6.07 4.08 121 5.14 6.24 5.14 5.14 6.24 5.14 4.72 6.07 4.08 120 5.14 6.24 5.14 5.14 6.24 5.14 4.31 6.07 4.08 119 5.24 6.24 5.14 5.24 6.24 5.14 4.06 6.07 4.08 118 5.26 6.24 5.14 5.26 6.24 5.14 4.12 6.07 4.08 117 5.34 6.30 5.20 5.34 6.30 5.20 4.66 6.07 4.08 116 5.46 6.34 5.22 5.46 6.34 5.22 4.66 6.07 4.18 115 5.48 6.40 5.24 5.48 6.40 5.24 4.68 6.07 4.26 114 5.52 6.46 5.29 5.52 6.46 5.29 4.70 6.07 4.36 113 5.56 6.52 5.34 5.56 6.52 5.34 4.70 6.07 4.46 112 5.52 6.58 5.32 5.52 6.58 5.32 4.72 6.07 4.54 111 5.52 6.62 5.32 5.52 6.62 5.32 4.74 6.07 4.64 110 5.60 6.68 5.38 5.60 6.68 5.38 4.82 6.07 4.82 109 5.52 6.74 5.37 5.52 6.74 5.37 4.86 6.07 4.82 108 5.58 6.80 5.42 5.58 6.80 5.42 4.74 6.18 4.76 107 5.68 6.86 5.48 5.68 6.86 5.48 4.70 6.27 4.60 106 5.70 6.92 5.48 5.70 6.92 5.48 4.96 6.38 4.68 105 5.72 6.98 5.52 5.72 6.98 5.52 4.88 6.48 4.76 104 5.74 7.04 5.54 5.74 7.04 5.54 4.84 6.59 4.54 103 5.70 7.10 5.40 5.70 7.10 5.40 4.74 6.69 4.68 102 5.62 7.16 5.34 5.62 7.16 5.34 4.82 6.80 4.60 101 5.58 7.22 5.34 5.58 7.22 5.34 4.82 6.90 4.62 100 5.54 7.30 5.24 5.54 7.30 5.24 4.86 7.01 4.62 99 5.52 7.36 5.18 5.52 7.36 5.18 5.38 7.12 4.96 98 5.42 7.42 5.14 5.42 7.42 5.14 5.06 7.23 4.99 97 5.42 7.48 5.12 5.42 7.48 5.12 5.10 7.34 4.82 96 5.44 7.54 5.06 5.44 7.54 5.06 5.20 7.45 4.88 95 5.38 7.62 5.00 5.38 7.62 5.00 5.04 7.56 4.92 94 5.38 7.68 4.98 5.38 7.68 4.98 5.44 7.67 5.22 93 5.44 7.74 5.02 5.44 7.74 5.02 5.28 7.78 4.96 92 5.46 7.82 5.00 5.46 7.82 5.00 5.68 7.90 5.44 91 5.46 7.88 4.96 5.46 7.88 4.96 5.80 8.01 5.60 90 5.54 7.94 5.04 5.54 7.94 5.04 5.86 8.12 5.58 89 5.48 8.02 5.02 5.48 8.02 5.02 6.18 8.24 5.72 88 5.52 8.08 5.08 5.52 8.08 5.08 6.06 8.34 5.87 87 5.56 8.16 5.10 5.56 8.16 5.10 6.27 8.46 6.08 86 5.60 8.22 5.20 5.60 8.22 5.20 6.28 8.60 6.02 85 5.58 8.30 5.14 5.58 8.30 5.14 6.42 8.70 5.92 84 5.64 8.38 5.16 5.64 8.38 5.16 6.46 8.82 6.16 83 5.64 8.44 5.12 5.64 8.44 5.12 6.46 8.94 6.24 82 5.68 8.52 5.22 5.68 8.52 5.22 6.60 9.06 6.20 81 5.78 8.58 5.32 5.78 8.58 5.32 6.62 9.18 6.30 80 5.90 8.66 5.54 5.90 8.66 5.54 6.66 9.30 6.22 79 6.03 8.74 5.74 6.03 8.74 5.74 6.70 9.42 6.28 78 6.18 8.82 5.92 6.18 8.82 5.92 6.86 9.54 6.52 77 6.36 8.88 6.08 6.36 8.88 6.08 6.76 9.66 6.52 76 6.52 8.96 6.20 6.52 8.96 6.20 6.88 9.79 6.50 75 6.66 9.04 6.36 6.66 9.04 6.36 7.02 9.92 6.66 74 6.84 9.12 6.48 6.84 9.12 6.48 7.20 10.04 6.92 73 6.98 9.20 6.68 6.98 9.20 6.68 7.28 10.16 7.10 72 7.01 9.28 6.78 7.01 9.28 6.78 7.62 10.28 7.36 71 7.02 9.36 6.88 7.02 9.36 6.88 7.88 10.42 7.68 70 7.03 9.44 7.01 7.03 9.44 7.01 8.12 10.54 7.96 69 7.03 9.50 7.01 7.03 9.50 7.01 8.32 10.66 8.24 68 7.03 9.50 7.01 8.40 10.80 8.30 67 7.03 9.50 7.01 8.70 10.92 8.46 66 8.84 11.06 8.72

Next: 10.2.3 Noise Models Up: 10.2 Spectral Flux Extraction Previous: 10.2.1 Determination of Echelle-Order
Karen Levay
12/4/1997