UV_PREVIEW returns the list of possible line channels through
variable PREVIEW%CHANNELS. If no line emission was identified at any
scale, the list is empty and the variable does not exist.
With this list, the user can compute the continuum image, using commands
UV_FILTER /CHANNELS PREVIEW%CHANNELS (or simply UV_FILTER), then UV_CON-
TINUUM and the usual UV_MAP and CLEAN. Alternatively, the user can fil-
ter out the continuum emission using UV_BASELINE.
If a catalog is present, UV_PREVIEW also creates several other vari-
ables. PREVIEW%FOUND indicates the spectral line falling in the fre-
quency range, while PREVIEW%DETECTED indicates the dectected lines.
These two structures have the following variables, e.g. for FOUND:
PREVIEW%Found%FREQ The line frequencies
PREVIEW%Found%LINES The line names
PREVIEW%Found%SPECIES The molecule name
PREVIEW%EDGES and PREVIEW%FREQUENCIES contains the start and end
channels (for %EDGES, resp. frequencies for %FREQUENCIES) of each
contiguous range of channels in PREVIOUS%CHANNELS. These variables
are used for line identification and imaging in the
@ image_lines
script.
Finally, UV_PREVIEW returns in PREVIEW%FMIN PREVIEW%FMAX the frequency
coverage, and in PREVIEW%FREQ the rest frequency of the most likely
spectral line in the window, and in PREVIEW%LINES its name. If no spec-
tral line has been identified, PREVIEW%FREQ is just the mean of PRE-
VIEW%FMIN and PREVIEW%FMAX, and PREVIEW%LINES does not exist.
Gildas manager
2023-06-01