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FEPS Pleiades Star HII_173:
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In this demo, we extract photometry for the target of small-field 70 um photometry observations. This demo continues from the mosaicking step.
To follow all of the examples using these data, going from retrieving data using Leopard through extracting point-source fluxes, see this page.
unix% cd r5315584/ch1/bcd/ unix% mv /where/you/downloaded/apex_1frame_MIPS70.nl ./cdf/ unix% nedit cdf/apex_1frame_MIPS70.nl |
Edit the namelist to reflect the absolute pathnames, including the PRF you want to start from. Normally, it's best to create your own custom PRF for your own observations, but in this case, there aren't really any bright (known) sources, so we can't construct our own from this single observation. So, we have to depend on the version that came with the MOPEX package, or the version that is available online.
unix% apex_1frame.pl -n apex_1frame_MIPS70.nl OR unix% mkdir pbcd70 unix% apex_1frame.pl -n apex_1frame_MIPS70.nl > pbcd70/apex.log & |
The star that is the target of this observation should be dead on in the center, but there doesn't appear to be anything there. It's very likely that this step will not catch anything at this location. (actual apex log file) The parameters in the namelist are set such that the extraction step is included, and the final file with extracted sources is mosaic70_extract.tbl. It completes successfully, but it indeed does not find any sources even meeting our selection criteria, much less at the center of the field.
unix% spot unix% nedit pbcd70/Combine/mosaic70_extract.tbl |
In theory, had we found anything, we could have used the same trick as we did with 24 um to find the object. However, in this case, there are no detections. We can still use Spot to create a nice fade between the two observations.
Start up Spot, and load in the 24 um mosaic (images menu/fits file option) -- no AORs needed. Be sure to load the file you just created -- r5315584/ch1/bcd/pbcd24/Combine/mosaic.fits. Next, load in the 70 um mosaic you just created: ch2/bcd/pbcd70/Combine/mosaic.fits. Click on the little "%" icon on the right side of the spot window and change the transparency of the 70 um image to watch the 24 fade into and out of 70 um. (two figs: one, two) There sure doesn't seem to be anything at our source position, but there's something nice and bright near an edge at 70, and it corresponds to a source seen at 24 -- it was source 197 in the 24 um source list. There is very little redundancy at 70 um in that position, so any photometry for this source will have very high errors.
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