Oscillation Parameters

The &osc namelist group defines oscillation parameters; the input file can contain one or more, but only the last (tag-matching) one is used. Allowable parameters are:

inner_bound (default 'REGULAR')

Inner boundary conditions; one of:

  • 'REGULAR' : Regularity-enforcing (only valid when inner grid point is at \(x = 0\))

  • 'ZERO_R' : Zero radial displacement (only valid when inner grid point is at \(x \ne 0\))

  • 'ZERO_H' : Zero horizontal displacement (only valid when inner grid point is at \(x \ne 0\))

outer_bound (default 'VACUUM')

Outer boundary conditions; one of:

  • 'VACUUM' : Zero surface pressure

  • 'DZIEM' : Formulation following Dziembowski (1971)

  • 'UNNO' : Formulation following Unno et al. (1989)

  • 'JCD' : Formulation following Jørgen Christensen-Dalsgaard (ADIPLS)

  • 'ISOTHERMAL' : Formulation based on local dispersion analysis for isothermal atmosphere

  • 'GAMMA' : Vanishing displacement and derivative at outer boundary, intended for use with \(\gamma\) modes (isolated g modes; see Ong & Basu, 2020)

outer_bound_cutoff (default '')

Outer boundary conditions to use when evaluating cutoff frequencies (see freq_units); same options as outer_bound, and if left blank then takes its value from outer_bound

outer_bound_branch (default 'E_NEG')

Dispersion relation solution branch to use for outer boundary conditions (when outer_bound='UNNO'|'JCD'|'ISOTHERMAL'); one of

  • 'E_NEG' : Outward-decaying energy density

  • 'E_POS' : Outward-growing energy density

  • 'F_NEG' : Outward energy flux

  • 'F_POS' : Inward energy flux

  • 'V_NEG' : Outward phase velocity

  • 'V_POS' : Inward phase velocity

variables_set (default 'GYRE')

Dependent variables in oscillation equations; one of:

  • 'GYRE' : GYRE formulation, as described in the Dimensionless Formulation section

  • 'DZIEM' : Formulation following Dziembowski (1971)

  • 'JCD' : Formulation following Jørgen Christensen-Dalsgaard (ADIPLS)

  • 'MIX' : Mixed formulation ('JCD' for gravitational components, 'DZIEM' for mechanical components)

  • 'LAGP' : Lagrangian pressure perturbation formulation

alpha_grv (default 1.)

Scaling factor for gravitational potential perturbations (see the \(\alphagrv\) variable in the Physics Switches section)

alpha_thm (default 1.)

Scaling factor for the thermal timescale (see the \(\alphathm\) variable in the Physics Switches section)

alpha_hfl (default 1.)

Scaling factor for horizontal flux perturbations (see the \(\alphahfl\) variable in the Physics Switches section)

alpha_gam (default 1.)

Scaling factor for g-mode isolation (see the \(\alphagam\) term in variable in the Physics Switches section)

alpha_pi (default 1.)

Scaling factor for p-mode isolation (see the \(\alphapi\) term in variable in the Physics Switches section)

alpha_kar (default 1.)

Scaling factor for opacity density partial derivative (see the \(\alphakar\) variable in the Physics Switches section)

alpha_kat (default 1.)

Scaling factor for opacity temperature partial derivative (see the \(\alphakat\) variable in the Physics Switches section)

alpha_rht (default 0.)

Scaling factor for time-dependent term in radiative heat equation (see the \(\alpharht\) variable in the Physics Switches section)

inertia_norm (default 'BOTH')

Inertia normalization factor; one of

  • 'RADIAL' : Radial amplitude squared, \(|\xi_{\rm r}|^{2}\), evaluated at x_ref

  • 'HORIZ' : Horizontal amplitude squared, \(|\lambda| |\xi_{\rm h}|^{2}\), evaluated at x_ref

  • 'BOTH' : Overall amplitude squared, \(|\xi_{\rm r}|^{2} + |\lambda| |\xi_{\rm h}|^{2}\), evaluated at x_ref

time_factor (default 'OSC')

Time-dependence factor in pulsation equations; one of:

  • 'OSC' : Oscillatory, \(\propto \exp(-{\rm i} \sigma t)\)

  • 'EXP' : Exponential, \(\propto \exp(-\sigma t)\)

conv_scheme (default 'FROZEN_PESNELL_1'`)

Scheme for treating convection; one of:

  • 'FROZEN_PESNELL_1' : Freeze convective heating altogether; case 1 described by Pesnell (1990)

  • 'FROZEN_PESNELL_4' : Freeze Lagrangian perturbation of convective luminosity; case 4 described by Pesnell (1990)

zeta_scheme (default PESNELL)

Scheme for evaluating dimensionless frequency weight function \(\sderiv{\zeta}{x}\) and integral eigenfrequency \(\omega_{\rm int}\); one of:

deps_scheme (default 'MODEL')

Scheme for calculating nuclear energy generation partials \(\epsrho\) and \(\epsT\); one of:

  • 'MODEL' : Use values from model

  • 'FILE' : Use complex (phase-lagged) values from separate file

deps_file (default '')

Name of epsilon partial derivatives file (when deps_scheme='FILE')

deps_file_format (default 'WOLF')

Format of epsilon partial derivative file (when deps_scheme='FILE'); one of:

x_ref (default 1 or outer grid point, whichever is smaller)

Reference fractional radius for photosphere, normalizations etc.

x_atm (default -1, implying outer grid point)

Fractional radius for convection-zone crossover point of \(\pi/\gamma\) modes (isolated p and g modes; see Ong & Basu, 2020)

adiabatic (default .TRUE.)

Flag to perform adiabatic calculations

nonadiabatic (default .FALSE.)

Flag to perform non-adiabatic calculations

quasiad_eigfuncs (default .FALSE.)

Flag to calculate quasi-adiabatic entropy/luminosity eigenfunctions during adiabatic calculations

reduce_order (default .TRUE.)

Flag to reduce the order of the adiabatic radial-pulsation equations from 4 to 2

tag_list (default '', which matches all)

Comma-separated list of &mode tags to match