Problems in Iraf

[valdes]

From: Nazhatulshima Ahmad <a_naz8898@yahoo.com.sg (a_naz8898@yahoo.com.sg)>
Date: November 8, 2005 7:17:28 PM MST
To: iraf <iraf@noao.edu (iraf@noao.edu)>
Subject: Problems in Iraf


Dear sir,
Hope you still remember me.As usual, I have a few
questions of iraf to ask.
1. After extracting the spectrum to 1-D the imagefile
supposed had an extension of .ms, right? Now the
problem is the imagefile still in 3-D format,because
the header shows:Spica300_FF.ms[765,1,3][real]:Spica.
So I stucked in calibration process. 


2. The analysis process now was getting very slow than
when I used it before. For the iraf to display the
image takes quite a few minutes.This is different when
I used it in the early stage. Is this a common problem
or there is way to solve?


That all for now, I hope for your advice for the
problems  above.


Thank you very much.


Naz.



From: Frank Valdes <valdes@noao.edu (valdes@noao.edu)>
Date: November 14, 2005 2:03:16 PM MST
To: Nazhatulshima Ahmad <a_naz8898@yahoo.com.sg (a_naz8898@yahoo.com.sg)>
Subject: Re: Problems in Iraf


Hello Naz,


The "multispec" format, which is what the ms extension means, may contain multiple 1D spectra as well as sky and error spectra.  Each of these are stored as lines in the file.  So the file is not always 1D.  In your case, you have a 1D spectrum with 765 pixels,  you have only 1 spectrum, and that spectrum has three associated pieces.  My guess is that you have extracted spectrum with and without variance weighting or cleaning, and an uncertainty spectrum.  You don't really need to be concerned about the associated spectra.  If you don't want this to be extracted into the file you would set the "extras" parameter in APALL or whatever task you used to extract the spectra to the value "no".  Everything seems to be fine with the header you show so you can go on with the calibration process.


I do not know what is causing the image display to be slow.


Yours,
Frank Valdes






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