20.20.5 Output

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_CONTINUUM and the usual UV_MAP and CLEAN. Alternatively, the user can filter out the continuum emission using UV_BASELINE.

If a catalog is present, UV_PREVIEW also creates several other variables. PREVIEW%FOUND indicates the spectral line falling in the frequency 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 contain 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 spectral line has been identified, PREVIEW%FREQ is just the mean of PREVIEW%FMIN and PREVIEW%FMAX, and PREVIEW%LINES does not exist.