another question about extracting spectum (tracing)
Mao yewei wrote on Jul 14, 2007
dear all,
i am faced with an important question about extracting 1D-spectum. i extracted several spectra from different parts of a galaxy in one slit. Except the core area, the continuum from other part of a galaxy is too weak to be traced, so when tracing, the RMS must be too large. i don't know what to do. Select "not tracing"? or else?
i think spetra in those parts shouldn't be traced but follow the tracing of spectrum from core area.
But what can i do?
:(
i am faced with an important question about extracting 1D-spectum. i extracted several spectra from different parts of a galaxy in one slit. Except the core area, the continuum from other part of a galaxy is too weak to be traced, so when tracing, the RMS must be too large. i don't know what to do. Select "not tracing"? or else?
i think spetra in those parts shouldn't be traced but follow the tracing of spectrum from core area.
But what can i do?
:(
Francisco Valdes wrote on Jul 14, 2007
Hi,
The approach you should take is to edit the apertures using the core tracing as the reference. In this mode you can shift the center by some amount or set the lower and upper edges (:lower, :upper or 'l' and 'u' keys (I think)) to something else. Then extract while turning the tracing off. For example is the aperture position and edges at the reference line/colum are something like
256 324.3 -5 5
You would change it to something like
256 324.3 -35 -25
Yours,
Frank Valdes
The approach you should take is to edit the apertures using the core tracing as the reference. In this mode you can shift the center by some amount or set the lower and upper edges (:lower, :upper or 'l' and 'u' keys (I think)) to something else. Then extract while turning the tracing off. For example is the aperture position and edges at the reference line/colum are something like
256 324.3 -5 5
You would change it to something like
256 324.3 -35 -25
Yours,
Frank Valdes
Last post on Jul 14, 2007