hifa_fluxcalflag

hifa_fluxcalflag(vis=None, field=None, intent=None, spw=None, threshold=None, appendlines=None, linesfile=None, applyflags=None) → ResultsList[Results][source]

Locate and flag line regions in solar system flux calibrators.

If the flux calibrator is a solar system object (SSO), known lines in the object are flagged by this task. The frequency width flagged is based on published spectra of 1 or 2 transitions of the species, and scaled to maintain consistent velocity widths for other transitions. Because the flags are applied in topocentric frame, the final width is further broadened by the maximum relative velocity between the object and the geocenter (computed over a decade).

The following lines are flagged per SSO:

  • Mars: 12CO (all ALMA bands), 13CO

  • Venus: 12CO (all ALMA bands), 13CO

  • Titan: 12CO, 13CO, HCN, H13CN, HC15N, HCN v2=1, CH3CN (through Band 8)

  • Neptune: 12CO

The topocentric frequency ranges flagged (in GHz) per species and object are:

Mars:
  CO:    [115.204,115.338], [230.404,230.672], [345.595,345.997], [460.773,461.309],
         [691.071,691.875], [806.184,807.120], [921.265,922.335]
  13CO:  [110.190,110.212], [220.377,220.421], [330.555,330.621], [440.721,440.809],
         [661.001,661.133], [771.108,771.260], [881.196,881.370]

Venus:
  CO:    [115.206,115.337], [230.407,230.669], [345.600,345.992], [460.779,461.303],
         [691.081,691.865], [806.194,807.110], [921.277,922.323]
  13CO:  [110.192,110.210], [220.380,220.418], [330.560,330.616], [440.727,440.803],
         [661.011,661.123], [771.118,771.250], [881.208,881.358]

Titan:
  CO:    [114.92,115.67], [229.49,231.74], [343.82,347.62], [458.29,463.80],
         [687.75,694.66], [803.46,809.85]
  13CO:  [110.18,110.22], [220.28,220.52], [330.36,330.82], [440.42,441.15],
         [660.60,661.53], [770.65,771.72], [880.73,881.82]
  HCN:   [88.45,88.81], [176.73,177.80], [264.96,266.81], [353.29,355.72],
         [441.74,444.52], [618.45,622.16], [707.01,710.74], [795.56,799.31], [883.82,887.86]
  HC15N: [86.04,86.07], [172.05,172.16], [258.04,258.27], [430.02,430.45],
         [601.95,602.60], [773.88,774.64], [859.84,860.62]
  H13CN: [86.33,86.35], [172.63,172.73], [258.91,259.11], [431.44,431.88],
         [603.98,604.56], [776.48,777.16], [862.72,863.42]
  HCN v2=1: [177.192,177.286], [178.088,178.184], [265.782,265.924], [267.128,267.270],
         [354.365,354.555], [356.161,356.351], [442.942,443.178], [445.184,445.422],
         [620.058,620.390], [623.197,623.529], [708.596,708.974], [712.182,712.562],
         [797.117,797.543], [801.149,801.577], [885.619,886.091], [890.096,890.572]
  CH3CN: [91.938,92.008], [110.304,110.409], [128.659,128.809], [147.039,147.209],
         [165.415,165.608], [183.792,184.006], [202.168,202.403], [220.543,220.798],
         [238.916,239.194], [257.289,257.587], [275.660,275.980], [294.030,294.371],
         [312.399,312.761], [330.766,331.149], [349.205,349.534], [367.572,367.920],
         [385.938,386.303], [404.301,404.683], [422.735,423.062], [441.098,441.440],
         [459.459,459.814], [477.881,478.186], [496.239,496.557]

Neptune:
  CO:    [113.99,116.51], [226.98,234.52], [339.97,351.54], [454.95,467.55],
         [685.93,696.57], [802.92,810.58]

The WebLog reports if any flagging was required, and if this resulted in the need to use a spw-map. If more than 75% of a given spw is flagged on the flux calibrator for the above lines, then a reference spw-map (refspwmap) is calculated and stored in the pipeline context so that later in hifa_gfluxscale, the fluxscale task will transfer the flux scale from the nearest other spw.

Additional spectral ranges to flag can be manually specified via the linesfile parameter. The file format is four space-delimited values per line: field name, line name, start frequency (GHz), stop frequency (GHz). The built-in list can be ignored in favor of user-specified ranges by setting appendlines=False.

Parameters:

  • vis -- The list of input MeasurementSets. Defaults to the list of MeasurementSets defined in the pipeline context.

  • field --

    The list of field names or field ids for which the models are to be set. Defaults to all fields with intent 'AMPLITUDE'.

    Example: field='3C279', field='3C279, M82'

  • intent --

    A string containing a comma delimited list of intents against which the selected fields are matched. Defaults to all data with amplitude intent.

    Example: intent='AMPLITUDE'

  • spw --

    Spectral windows and channels for which bandpasses are computed. Defaults to all science spectral windows.

    Example: spw='11,13,15,17'

  • threshold -- If the fraction of a spectral window occupied by line regions is greater than this threshold value, then flag the entire spectral window.

  • appendlines -- Append user defined line regions to the line dictionary.

  • linesfile -- Read in a file containing lines regions and append it to the builtin dictionary. Blank lines and comments beginning with # are skipped. The data is contained in 4 whitespace delimited fields containing the solar system object field name, e.g. 'Callisto', the molecular species name, e.g. '13CO', and the starting and ending frequency in GHz.

  • applyflags -- Boolean for whether to apply the generated flag commands. (default True)

Notes

QA Scoring

A QA score of 0.66 is set if a spw-map was required, otherwise 1.0. There is an additional QA score based on the incremental amount of flagging: 0.0 if the flag fraction is >=50%, 1.0 if <=5%, linearly interpolated in between.

Returns:

The results object for the pipeline task is returned.

Examples

  1. Locate known lines in any solar system object flux calibrators:

>>> hifa_fluxcalflag()