Apscatter for long-slit spectroscopy
jchavez wrote on Jan 28, 2011
Hi,
I would like to subtract scattered light across the dispersion (not necessarily along the disperson, although that wouldn't hurt). I have 3 stars in the slit. When I extracted the spectra, I got 3 apertures.
I'm trying to apscatter. I set to use the database of the extracted apertures (find, recenter, resize, edit, trace, fittrace I set all to 'no', and gave it the reference). The output of apscatter, though, has 70 apertures - which look nothing like the the 3 that I extracted.
What am I missing in this task? Is that what it is supposed to give? I would like to extract the 3 stars' spectrum with the scattered light subtracted. Is this not the right way to do this?
Thank you!
-Joy
I would like to subtract scattered light across the dispersion (not necessarily along the disperson, although that wouldn't hurt). I have 3 stars in the slit. When I extracted the spectra, I got 3 apertures.
I'm trying to apscatter. I set to use the database of the extracted apertures (find, recenter, resize, edit, trace, fittrace I set all to 'no', and gave it the reference). The output of apscatter, though, has 70 apertures - which look nothing like the the 3 that I extracted.
What am I missing in this task? Is that what it is supposed to give? I would like to extract the 3 stars' spectrum with the scattered light subtracted. Is this not the right way to do this?
Thank you!
-Joy
Francisco Valdes wrote on Jan 28, 2011
I am sorry for the delay in replying.
Apscatter is definitely what you want to use. I am not sure what you are doing wrong. If you send a command line, the parameter settings (lpar apscatter), and any log or terminal output I could probably tell you what you need to do.
My guess is you are using the wrong reference. What you could do is specify the input image that you've already extracted without first removing the scattered light and no reference. Then it should definitely use the same apertures. Specify an output image. After the scattered light has been fit and subtract you then go back with apall or apsum to redo the extractions.
I hope this helps.
Frank Valdes
Apscatter is definitely what you want to use. I am not sure what you are doing wrong. If you send a command line, the parameter settings (lpar apscatter), and any log or terminal output I could probably tell you what you need to do.
My guess is you are using the wrong reference. What you could do is specify the input image that you've already extracted without first removing the scattered light and no reference. Then it should definitely use the same apertures. Specify an output image. After the scattered light has been fit and subtract you then go back with apall or apsum to redo the extractions.
I hope this helps.
Frank Valdes
Last post on Jan 28, 2011