Split Continuum and Spectral line imaging
Keywords: imager

Next: Combined Continuum and Spectral Up: Continuum emission Previous: Continuum imaging Contents Index

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Split Continuum and Spectral line imaging

To image the spectral line, we simply remove in the plane the continuum defined before and image the resulting spectral line data:
magenta `uv_baseline`
`uv_map`
`clean` (and optionally magenta`uv_restore`)

The last step is to add back to this image the deconvolved continuum one:
magenta `define image my_clean * real /like clean /global`
`map_combine my_clean ADD clean continuum`
where the last command is equivalent to the following loop:
`let my_clean% clean% ! Set its header`
`for i 1 to clean%dim[3]`
`let my_clean[i] clean[i]+continuum`
`next`
Because the Fourier Transform is a linear operation, we end up with a combined data set that properly includes all the emission, line and continuum, deconvolved in a (well almost...) 9optimal way.

Further analysis of the spatial variations of the continuum emission (including variations of its spectral index) can be done on this combined image that contains all the information, see Sec.

Note that we used in this example commands magenta`uv_filter` and magenta`uv_baseline` with their default behaviour provided by magenta`uv_preview`: the user could specify more adapted values using the command options and/or control variables if needed.

Next: Combined Continuum and Spectral Up: Continuum emission Previous: Continuum imaging Contents Index