nifs Ronchi

monikval wrote on Sep 28, 2009

Hi,

Getting the s-curvature+distortion with GEMINI-NIFS, after running the task NSREDUCE, iraf produces this message:
"
WARNING - NSREDUCE: The slit for image comNRonchiOn5s3 does not match
the flat image slit. Proceeding anyway.
NSREDUCE: slit: Ronchi_Screen_G5615
NSREDUCE: grism: HK_G0603
"
but then, also says:
"
n input --> output sky image
dark flat scale

1 comNRonchiOn5s3 --> RcomNRonchiOn5s3
none
tmpdark3501dzc newSlitFlat5s3 1.0000

NSREDUCE exit status: good.
"
Am I doing something wrong? or the "status: good" means that I should not worry about the not matching of the slits?

Thanks for your help,
Cheers,
Monik.

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James Turner wrote on Sep 28, 2009

I haven't personally reduced NIFS science data, but as far as I can tell this is harmless. The task nsreduce is used by several instruments, hence the "slit" terminology. In this case, you would expect a different focal plane mask for the Ronchi flats and the normal flats (only one of them has the Ronchi screen), but more generally when reducing spectroscopic data you'd expect to have the same thing(s) in the focal plane for the flats and the file you're reducing.

Cheers,

James (Gemini South).

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Last post on Sep 28, 2009