Results
Figure 1 shows one DCE where the star is clearly seeing [pixel(22,13)]
in the Wide Field. Figure 2 shows the radial profile of the star based on the 10sec mosaic.
Figure 3 shows the star in a Narrow Field frame for one DCE (source at pixel (20,14).
Figure 4. Shows the mosaic created by Dr. Alonso-Herrero a week later using the corrected pointing
and better illumination correction of the 3 and 10sec observations of HD183439 in the
Wide and Narrow Field modes.
Figure 1: Star HD 183439 on a Single DCE
in the 70um Wide Field mode.
Figure 1: Radial profile of HD 183439
in the 70um Wide Field mode
Figure 3: Star HD 183439 on a Single DCE
in the 70um Narrow Field mode.
Figure 3: Mosaic of the 70um Wide and Narrow Field modes
of HD183439 (Alonso-Herrero).
System Throughput
Following task MIPS-922, the total counts from the star were determined by using
a 5 pixel radius for the aperture, and a 4 pixel annulus - from 8 to 12 pixels -
for the sky. The counts in the Wide field 3 and 10sec observations were 0.34 and 0.41
DN/s. The median sky annuli counts were 0.018 and 0.017 DN/sec, respectively.
I borrowed Chad's (see MIPS-922) aperture size correction of 1.15. The flux
for HD183439 is 0.582 Jy at 70um, therefore the DN/s to Jy ratio is (using the
better S/N of the 10sec measurements): 0.41*1.15/0.582 = 0.81. The background level
for 0.0170 DN/s implies a surface density:
0.0170 DN/s/0.81 DN/s/JY*1.e-6 MJy/J/(9.84/206265)**2 sr/pix = 9.1 MJy/sr
slightly lower than the predicted by SPOT (11.80MJy/sr on Oct 10, 2003),
but our conversion factor could be off by as much as 25%.
(Notice that the 0.34 DN/s measurement from the 3sec observations give a 0.67 DN/s/Jy
factor, closer to that determined in MIPS-922 - 0.63 - and give a background of 11.11 MJy/sr)
The Narrow Field data was too noise to perform a similar exercise.