Frequency Scan Parameters

The &scan namelist group defines frequency grid parameters, as follows:

grid_type (default 'LINEAR')

Distribution of frequency points; one of:

  • 'LINEAR' : Uniform in frequency

  • 'INVERSE' : Uniform in inverse frequency

  • 'FILE' : Read from file

grid_frame (default 'INERTIAL')

Reference frame in which grid_type applies; one of:

  • 'INERTIAL' : Inertial frame

  • 'COROT_I' : Co-rotating frame at inner boundary

  • 'COROT_O' : Co-rotating frame at outer boundary

freq_min (default 1)

Minimum frequency, when grid_type is 'LINEAR' or 'INVERSE'

freq_max (default 10)

Maximum frequency, when grid_type is 'LINEAR' or 'INVERSE'

n_freq (default 10)

Number of frequency points, when grid_type is 'LINEAR' or 'INVERSE'

freq_units (default NONE)

Units of freq_min and freq_max, when grid_type is 'LINEAR' or 'INVERSE'; units of read frequencies when grid_type is 'FILE'

  • 'NONE' : Dimensionless angular frequency

  • 'HZ' : Linear frequency in Hz[1]

  • 'UHZ' : Linear frequency in \(\mu\)Hz[1]

  • 'RAD_PER_SEC' : Angular frequency in radians per second[1]

  • 'CYC_PER_DAY' : Linear frequency in cycles per day[1]

  • 'ACOUSTIC_DELTA' : Fraction of the asymptotic acoustic large frequency separation \(\Delta \nu\)

  • 'GRAVITY_DELTA' : Fraction of the asymptotic inverse gravity period separation \((\Delta P)^{-1}\)

  • 'UPPER_DELTA' : Greater of \(\Delta \nu\) and \((\Delta P)^{-1}\)

  • 'LOWER_DELTA' : Lesser of \(\Delta \nu\) and \((\Delta P)^{-1}\)

  • 'ACOUSTIC_CUTOFF' : fraction of the acoustic cutoff frequency[1]

  • 'GRAVITY_CUTOFF' : fraction of the gravity cutoff frequency[1]

  • 'ROSSBY_I' : fraction of Rossby frequency (see eqn. 15) at inner boundary

  • 'ROSSBY_O' : fraction of Rossby frequency (see eqn. 15) at outer boundary

freq_min_units (default '')

Units of freq_min; same options as freq_units and overrides it if set

freq_max_units (default '')

Units of freq_max; same options as freq_units and overrides it if set

freq_frame (default 'INERTIAL')

Reference frame in which freq_min and freq_max are defined, when grid_type is 'LINEAR' or 'INVERSE'; one of:

  • 'INERTIAL' : Inertial frame

  • 'COROT_I' : Co-rotating frame at inner boundary

  • 'COROT_O' : Co-rotating frame at outer boundary

file

File to read frequencies from, when grid_type is 'FILE'

axis (default 'REAL’)

Axis that scan applies to; one of

  • 'REAL' : Real axis

  • 'IMAG' : Imaginary axis

tag_list (default '', which matches all)

Comma-separated list of &mode tags to match

An input file can contain one or more &scan namelist group; the points defined by each (tag-matching) group are merged together to build the frequency grid. See the Frequency Grids section for further details.

Footnotes