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gyre / Namelist Input Files (3.1)

Overview

GYRE reads parameters from an input file which defines a number of Fortran namelists.

Where indicated, namelists are required in the input file — even if no parameters are specified.

Namelists

Stellar Model

The &model namelist defines the stellar model that GYRE works on; the input file should contain exactly one. Allowable fields are:

  • model_type : type of model to use ; one of:
    • 'HOM' : homogeneous compressible model
    • 'POLY' : polytropic model read from external file
    • 'EVOL' : evolutionary model read from external file
  • file : name of file (model_type is 'POLY' or 'EVOL')
  • file_format : format of file (model_type is 'EVOL'); one of
    • 'GSM' : GSM-format HDF5 file
    • 'MESA' : MESA GYRE-format text file
    • 'OSC' : OSC-format text file
    • 'FGONG' : FGONG-format text file
    • 'FAMDL' : FAMDL-format text file
  • data_format : Fortran format specifier for data read from OSC-, FGONG- and FAMDL-format files
  • Gamma_1 : first adiabatic exponent (model_type is 'HOM') (default 5/3)
  • deriv_type : spline interpolation derivatives type (model_type is 'POLY' or 'EVOL'); one of
    • 'NATURAL' : natural derivatives (C2-continous)
    • 'FINDIFF' : finite-difference derivatives
    • 'MONO' : monotonized derivatives (default)

Constants

The &constants namelist defines various physical constants; the input file should contain exactly one. Allowable fields are:

  • G_GRAVITY : gravitational constant
  • A_RADIATION : radiation constant
  • C_LIGHT : speed of light in vacuo
  • M_SUN : solar mass
  • R_SUN : solar radius
  • L_SUN : solar luminosity

All of these constants are in cgs units, and the default values are defined in core_constants.fpp.

Oscillation parameters

The &osc namelist defines oscillation parameters; the input file should contain one or more. Allowable fields are:

  • l : harmonic degree (default 0)
  • outer_bound_type :
  • variables_type :
    • 'DZIEM' : Use Dziembowski formulation of pulsation variables/equations (default)
    • 'JCD' : Use Christensen-Dalsgaard (ADIPLS) formulation of pulsation variables/equations
    • 'MIX' : Use mixed formulation of pulsation variables/equations (JCD for gravitational components, DZIEM for mechanical components)
  • inertia_norm_type :
    • 'RADIAL' : Use the radial amplitude squared at x_ref to normalize the mode inertia
    • 'HORIZ' : Use the horizontal amplitude squared x_ref to normalize the mode inertia
    • 'BOTH' : Use the overall amplitude squared at x_ref to normalize the mode inertia (default)
  • x_ref : reference radius for photosphere, normalizations etc. (default 1 or outer grid point, whichever is smaller)
  • tag : tag for controlling selection of other parameters
  • X_n_pg_min : filter for minimum radial order (experimental)
  • X_n_pg_max : filter for maximum radial order (experimental)

Numerical Parameters

The &num namelist defines numerical method parameters; the input file should contain one or more. Allowable fields are:

  • n_iter_max : maximum number of iterations in root-finding algorithm (default 50)
  • ivp_solver_type :
    • 'MAGNUS_GL2' : second-order Gauss-Legendre Magnus solver (default)
    • 'MAGNUS_GL4' : fourth-order Gauss-Legendre Magnus solver
    • 'MAGNUS_GL6' : sixth-order Gauss-Legendre Magnus solver
    • 'FINDIFF' : centered second-order finite differences
  • reduce_order : flag to reduce the order of the radial-pulsation equations from 4 to 2 (default .TRUE.)
  • use_banded : flag to use banded algorithms on the system matrix (default .FALSE.)
  • tag_list : comma-separated list of &osc tags to match (default '' matches all)

Frequency Scan

The &scan namelist(s) defines a set of points in frequency space to scan for changes in the sign of the discriminant (indicating that an eigenfrequency is bracketed); the input file should contain one or more. The points from each &scan namelist are merged together. Allowable fields are:

  • grid_type : distribution of frequency points; one of:
    • 'LINEAR' : uniform in frequency (default)
    • 'INVERSE' : uniform in period
  • freq_min : minimum frequency (default 1)
  • freq_max : maximum frequency (default 10)
  • n_freq: number of frequency point
  • freq_units : interpretation of freq_min and freq_max; one of:
    • 'NONE' : dimensionless angular frequency (default)
    • 'HZ' : linear frequency in Hz
    • 'UHZ' : linear frequency in μHz
    • 'ACOUSTIC_CUTOFF' : fraction of the acoustic cutoff frequency
    • 'GRAVITY_CUTOFF' : fraction of the gravity cutoff frequency
  • tag_list : comma-separated list of &osc tags to match (default '' matches all)

Multiple Shooting Grid

The &shoot_grid namelists define a sequence of opertations to build the grid used for multiple shooting (during eigenfrequency calculation); the input file should contain one or more. Each namelist applies a single operation — either creating a fresh grid, or modifying the grid produced by the preceding operation. Allowable fields are:

  • op_type : type of operation to apply; one of
    • 'CREATE_GEOM' : create a grid with geometric spacing
    • 'CREATE_LOG' : create a grid with logarithmic spacing
    • 'CREATE_UNIFORM' : create a grid with uniform spacing
    • 'CREATE_CLONE' : create a grid by cloning the model grid (default)
    • 'CREATE_MIDPOINT' : create a grid at the midpoints of the model grid
    • 'CREATE_FROM_FILE' : read a grid from an external file
    • 'RESAMP_DISPERSION' : resample the grid using a local dispersion analysis
    • 'RESAMP_THERMAL' : resample the grid using a thermal timescale analysis
    • 'RESAMP_CENTER' : resample the grid to ensure resolution of the center
    • 'RESAMP_UNIFORM' : resample the grid uniformly
  • n : context-dependent; one of:
    • number of grid points (op_type is 'CREATE_GEOM', 'CREATE_LOG' or 'CREATE_UNIFORM')
    • number of extra central points (op_type is 'RESAMP_CENTER')
    • number of extra points per cell (op_type is 'RESAMP_UNIFORM')
  • s : grid skewness parameter (op_type is 'CREATE_GEOM' or 'CREATE_LOG') (default 0)
  • alpha_osc : sampling rate in oscillatory regions (op_type is 'RESAMP_DISPERSION') (default 0)
  • alpha_exp : sampling rate in exponential regions (op_type is 'RESAMP_DISPERSION') (default 0)
  • alpha_thm : sampling rate (op_type is 'RESAMP_THERMAL') (default 0)
  • tag_list : comma-separated list of &osc tags to match (default '' matches all)

See Understanding Grids for further details.

Reconstruction Grid

The &recon_grid namelists define a sequence of operations to build the grid used for multiple shooting (during eigenfrequency calculation); the input file should contain one or more. Each namelist applies a single operation — either creating a fresh grid, or modifying the grid produced by the preceding operation. The allowable fields are the same as described above for the &shoot_grid namelists, with one small change: when op_type is 'CREATE_CLONE', the grid is cloned from the shooting grid, and not from the model grid.

See Understanding Grids for further details.

Output Files

The &output namelist defines the output produced created at the end of a run; the input file should contain exactly one. Allowable fields are:

  • summary_file : name of summary file
  • summary_file_format : format of summary file; one of
    • 'HDF' : HDF5 file (default)
    • 'TXT' : text file
  • summary_item_list : comma-separated list of items to write to summary file; see Output Files
  • mode_prefix : name prefix of mode files (overridden by mode_template). Names are generated by appending -NNNN.h5 (HDF-format files) or -NNNN.txt (TXT-format files), where NNNN is the run index of the mode
  • mode_template : name template of mode files (overrides mode_prefix). Names are generated using the following pattern substitutions:
    • %J : run index of mode, formatted in fixed-width field; counts from 1 upwards for each mode found during the GYRE run (unique)
    • %j : same as %J, but formatted in variable-width field
    • %L : harmonic degree of mode, formatted in fixed-width field
    • %l : same as %L, but formatted in variable-width field
    • %N : radial order of mode, formatted in fixed-width field
    • %n : same as %N, but formatted in variable-width field
  • mode_file_format : format of mode files; one of
    • 'HDF' : HDF5 file (default)
    • 'TXT' : text file
  • mode_item_list : comma-separated list of items to write to mode file; see Output Files
  • freq_units : interpretation of output freq data; one of:
    • 'NONE' : dimensionless angular frequency (default)
    • 'HZ' : linear frequency in Hz
    • 'UHZ' : linear frequency in μHz
    • 'ACOUSTIC_CUTOFF' : fraction of the acoustic cutoff frequency
    • 'GRAVITY_CUTOFF' : fraction of the gravity cutoff frequency

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