Osc Namelist Group

The &osc namelist group controls the treatment of the stellar oscillation equations. The input file can contain one or more, but only the last (tag-matching) one is used. The following options are available:

inner_bound (type: string, default: 'REGULAR')

Inner boundary conditions; one of

'REGULAR' : Regularity-enforcing[1]
'ZERO_R' : Zero radial displacement[2]
'ZERO_H' : Zero horizontal displacement[2]

outer_bound (type: string, default: 'VACUUM')

Outer boundary conditions; one of

'VACUUM' : Vanishing surface density
'ZERO_R' : Zero radial displacement
'ZERO_H' : Zero horizontal displacement
'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
'GAMMA1' : Vanishing displacement and derivative at outer boundary, intended for use with \(\gamma\) modes (isolated g modes; see Ong & Basu, 2020)
'GAMMA2' : Variant of 'GAMMA1' option described in PR #8

outer_bound_cutoff (type: string, 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 (type: string, default: 'E_NEG')

Dispersion relation solution branch to use for outer boundary conditions; 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

Used only when outer_bound = 'UNNO' | 'JCD' | 'ISOTHERMAL'

variables_set (type: string, 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 \(y_{3,4}\), 'DZIEM' for \(y_{1,2}\))
'LAGP' : Lagrangian pressure perturbation formulation

lambda_method (type: string, default: 'SPH')

Method adopted to evaluate the angular eigenvalue \(\lambda\); one of

'SPH' : Use the spherical-harmonic value \(\lambda=\ell(\ell+1)\)
'TAR-GRAVITY' : Use the traditional approximation of rotation, for gravito-acoustic modes
'TAR-ROSSBY' : Use the traditional approximation of rotation, for Rossby modes
'ADHOC : Use an ad-hoc value set by the lambda option

lambda (type: real, default: 0): Value of angular eigenvalue \(\lambda\). Used only when lambda_method = 'ADHOC'

complex_lambda (type: logical, default: .FALSE.): Use complex arithmetic when evaluating the angular angular eigenvalue \(\lambda\). Used only when lambda_method = 'TAR-GRAVITY' | 'TAR-ROSSBY'

alpha_grv (type: real, default: 1): Scaling factor for gravitational potential perturbations (see the \(\alphagrv\) entry in the Physics Switches section)

alpha_gbc (type: real, default: 1): Scaling factor for the displacement term in the outer gravitational potential boundary condition (see the \(\alphagbc\) entry in the Physics Switches section)

alpha_thm (type: real, default: 1): Scaling factor for the thermal timescale (see the \(\alphathm\) entry in the Physics Switches section)

alpha_hfl (type: real, default: 1): Scaling factor for horizontal flux perturbations (see the \(\alphahfl\) entry in the Physics Switches section)

alpha_gam (type: real, default: 1): Scaling factor for g-mode isolation (see the \(\alphagam\) term in entry in the Physics Switches section)

alpha_pi (type: real, default: 1): Scaling factor for p-mode isolation (see the \(\alphapi\) term in entry in the Physics Switches section)

alpha_kar (type: real, default: 1): Scaling factor for opacity density partial derivative (see the \(\alphakar\) entry in the Physics Switches section)

alpha_kat (type: real, default: 1): Scaling factor for opacity temperature partial derivative (see the \(\alphakat\) entry in the Physics Switches section)

alpha_rht (type: real, default: 0): Scaling factor for time-dependent term in radiative heat equation (see the \(\alpharht\) entry in the Physics Switches section)

alpha_trb (type: real, default: 0): Scaling factor for the turbulent mixing length (see the \(\alphatrb\) entry in the Physics Switches section)

alpha_con (type: real, default: 1): Exponent in the turbulent viscosity reduction factor (see the \(\alphacon\) entry in the Physics Switches section)

inertia_norm (type: string, 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 (type: string, 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 (type: string, 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)

deps_scheme (type: string, default: 'MODEL')

Scheme for calculating nuclear energy generation partials \(\epsnucrho\) and \(\epsnucT\); one of

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

deps_file (type: string, default: ''): Name of epsilon partial derivatives file. Used only when deps_scheme = 'FILE'

deps_file_format (type: string, default: 'WOLF')

Format of epsilon partial derivative file; one of

'WOLF' : Format used in preparation of Wolf et al. (2018)

Used only when deps_scheme = 'FILE'

x_ref (type: real, default: min(1, x_o)): Reference fractional radius for photosphere, normalizations etc.

x_atm (type: real, default: -1): Fractional radius for convection-zone crossover point of \(\pi/\gamma\) modes (isolated p and g modes; see Ong & Basu, 2020)

adiabatic (type: logical, default: .TRUE.): Perform adiabatic calculations

nonadiabatic (type: logical, default: .FALSE.): Perform non-adiabatic calculations

quasiad_eigfuncs (type: logical, default: .FALSE.): Calculate quasi-adiabatic entropy/luminosity eigenfunctions during adiabatic calculations

reduce_order (type: logical, default: .TRUE.): Reduce the order of the adiabatic radial-pulsation equations from 4 to 2

Footnotes