Line Catalog

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8.3.9.2 Line Catalog

ASAP allows loading a custom line catalog in ASCII format. The ASCII text file must have at least 4 columns with Molecule name, frequency in MHz, frequency error and intensity (any units). If the molecule name contains any spaces, they must be wrapped in quotes ””. A sample of the ASCII catalog is shown below.

     H2D+    3955.2551 228.8818  -7.1941
     H2D+   12104.7712 177.1558  -6.0769
     H2D+   45809.2731 118.3223  -3.9494
     CH       701.6811    .0441  -7.1641
     CH       724.7709    .0456  -7.3912
     CH      3263.7940    .1000  -6.3501
     CH      3335.4810    .1000  -6.0304

You can load the ASCII line catalog, for example, if it is called my_custom_linecat.txt, by following command.

mycatlog = sd.linecatlog(’my_custom_linecat.txt’)

Use sd.plotter.plot_line to overlay the line catalog on the plot. (Currently overplotting line catalog works only spectra plotted in frequency.)

  scans.set_unit(’GHz’)
  sd.plotter.plot(scans)
  sd.plotter.plot_line(mycatlog)

The following are some useful functions to control the line catalog access. See ASAP User Guide for more complete descriptions.

  mycatlog.save(’my_custom_linecat.tbl’) # save to the internal table format
  mycatlog.set_frequency_limits(100,115,’GHz’) #set a frequency range for line selection
  mycatlog.set_name(’*OH’) # select all alchols

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