Cutting emission lines
mv1612 wrote on May 31, 2006
Hi,
My first post here, if it is elementary I apologize, I just began learning IRAF. I'm working on some very high resolution spectra of a WR star. I need to cut the upper part of an emission line cause I would use the wings only for cross-correlation, to find a rotation curve. I have lots of spectra, so my question would be, can I do something like "cut the emission line from y=2 upwards and join the two wings by a straight line at y=2", for all the spectra simultaneously. The spectra are slightly moving in wavelength from one to the other, but the value y=2 would be good for all of them.
Thanks, Virgil.
My first post here, if it is elementary I apologize, I just began learning IRAF. I'm working on some very high resolution spectra of a WR star. I need to cut the upper part of an emission line cause I would use the wings only for cross-correlation, to find a rotation curve. I have lots of spectra, so my question would be, can I do something like "cut the emission line from y=2 upwards and join the two wings by a straight line at y=2", for all the spectra simultaneously. The spectra are slightly moving in wavelength from one to the other, but the value y=2 would be good for all of them.
Thanks, Virgil.
Mike Fitzpatrick wrote on May 31, 2006
If what you want is to simply clip all pixel values above 2 to the value 2, then look at IMREPLACE, e.g.
cl> imreplace spec* 2 lower=2.0
should do what you want.
-Mike
cl> imreplace spec* 2 lower=2.0
should do what you want.
-Mike
mv1612 wrote on May 31, 2006
It worked perfectly, thanks very much Mike!
Virgil.
Virgil.
Last post on May 31, 2006