binary_controls
specifications for starting model
m1
Initial mass of star 1 in Msun units. Not used when loading a saved model.
same caveats as initial_mass
in star/defaults/controls.defaults apply
m1 = 1.0d0
m2
Initial mass of star 2 in Msun units. Not used when loading a saved model.
same caveats as initial_mass
in star/defaults/controls.defaults apply
m2 = 0.8d0
initial_period_in_days
Initial orbital period in days.
initial_period_in_days = 0.5d0
initial_separation_in_Rsuns
Initial separation measured in Rsuns. Only used when initial_period_in_days < 0
initial_separation_in_Rsuns = 100
initial_eccentricity
Initial eccentricity of the system
initial_eccentricity = 0.0d0
controls for output
history_name
Name of file for binary output
history_name = 'binary_history.data'
history_interval
append an entry to the history.data file when
mod(model_number, history_interval) = 0
.
history_interval = 5
append_to_star_history
If true, then the columns from the binary_history
are also included
in each of the stars history files.
NOTE: if .false., then pgstar cannot access binary data
append_to_star_history = .true.
log_directory
Directory for binary output
log_directory = '.'
history_dbl_format
history_int_format
history_txt_format
Format for double, int and text in binary output
history_dbl_format = '(1pes32.16e3, 1x)'
history_int_format = '(i32, 1x)'
history_txt_format = '(a32, 1x)'
photo_interval
photo_digits
photo_directory
These overwrite the values of photo_interval
, photo_digits
and photo_directory
for each
star, so that profiles are outputted simultaneously
photo_interval = 50
photo_digits = 3
photo_directory = 'photos'
terminal_interval
write info to terminal when mod(model_number, terminal_interval) = 0
.
terminal_interval = 1
write_header_frequency
output the log header info to the terminal when
mod(model_number, write_header_frequency*terminal_interval) = 0
.
write_header_frequency = 10
extra_binary_terminal_output_file
if not empty, output terminal info to this file in addition to terminal.
this does not capture all of the terminal output – just the common items.
it is intended for use in situations where you cannot directly see the terminal
output such as when running on a cluster. if you want to be able to monitor
the progress for such cases, you can set extra_binary_terminal_output_file = 'log'
and then do tail -f log to view the terminal output as it is recorded in the file.
extra_binary_terminal_output_file = ''
timestep controls
The terminal output during evolution includes a short string for the ‘dt_limit’. This is to give you some indication of what is limiting the time steps. Here’s a dictionary mapping those terminal strings to the corresponding control parameters. These only include limits from binary, to see the limits from star refer to star/default/controls.defaults
terminal output related parameter
'b_companion' timestep limited by companion
'b_RL' fr
'b_jorb' fj
'b_envelope' fm
'b_separation' fa
'b_eccentricity' fe
'b_deltam' fdm
time_delta_coeff
similarly to star/time_delta_coeff, this time_delta_coeff can be scaled to force smaller timestep for binary timestep controls
time_delta_coeff = 1d0
fm
fm_hard
fa
fa_hard
fr
fr_hard
fj
fj_hard
fe
fe_hard
Timestep controls based on relative changes. After each step an upper limit is set on the timestep based on changes on different quantities. If the quantity is X and the change in one timestep dX, then this limit is given by
dt_next_max = dt * fX*abs(X / dX)
each of these controls deals with the following:
fm: envelope mass
fa: binary separation
fr: change in (r-rl)/rl
fj: change in orbital angular momentum
fe: change in orbital eccentricity
hard limits are strictly enforced, if a timestep exceeds that limit then a retry is made.
fm = 0.01d0
fm_hard = -1d0
fa = 0.01d0
fa_hard = 0.02d0
fr = 0.10d0
fr_hard = -1d0
fj = 0.001d0
fj_hard = 0.01d0
fe = 0.01d0
fe_hard = -1d0
fm_limit
fr_limit
fe_limit
Limits to timestep controls give by fm, fr and fe. As these three quantities evolve naturally to zero, following strictly the timestep limit given by fX would reduce timesteps infinetely. These fX_limit avoid this problem by computing the limit to the timestep as
dt_next_max = dt * fX*abs(max(abs(X),fX_limit) / dX)
If any of these fX_limit
is smaller than zero it is ignored.
fm_limit = 1d-3
fr_limit = 1d-2
fe_limit = 1d-1
fr_dt_limit
Minimum timestep limit allowed for the fr control in years.
fr_dt_limit = 10d0
fdm
fdm_hard
Limits the timestep based on the fractional mass change of either component.
fdm = 0.005d0
fdm_hard = 0.01d0
dt_softening_factor
Weight factor to average max_timestep
with old one (in log space) as in
dt_next_max = 10**(dt_softening_factor*log10(dt_next_max_old) + &
(1-dt_softening_factor)*log10(dt_next_max))
where dt_next_max_old
is the limit used in the previous step. This is meant
to avoid large changes in dt. Values must be < 1 and >= 0, 1 meaning constant dt,
0 meaning no softening
dt_softening_factor = 0.5d0
varcontrol_{stage}
Allows binary to set varcontrol_target
for each star depending on the
stage of evolution. Ignored if < 0. Each one controls the following stages,
varcontrol_case_a
varcontrol_target
for both stars during mass transferfrom a core hydrogen burning star.
varcontrol_case_b
varcontrol_target
for both stars during mass transferfrom a core hydrogen depleted star.
varcontrol_ms
:varcontrol_target
for a star that has not depleted core H.varcontrol_post_ms
:varcontrol_target
for a star that has depleted core H.
varcontrol_case_a = -1d0
varcontrol_case_b = -1d0
varcontrol_ms = -1d0
varcontrol_post_ms = -1d0
dt_reduction_factor_for_j
When a retry happens due to the hard limit in angular momentum changes, or because the timestep produced a negative j, further multiply the timestep by this factor for the next step. This can avoid multiple retries and waste of time.
dt_reduction_factor_for_j = 0.1d0
when to stop
accretor_overflow_terminate
terminate evolution if (r-rl)/rl is bigger than this for accretor
accretor_overflow_terminate = 0.0d0
terminate_if_initial_overflow
terminate evolution if first model of run is overflowing
terminate_if_initial_overflow = .true.
terminate_if_L2_overflow
terminate evolution if there is overflow through the second Lagrangian point Amount of overflow needed to reach L2 implemented as in Marchant et al. (2016), A&A, 588, A50
terminate_if_L2_overflow = .false.
mass transfer controls
mass_transfer_*
Transfer efficiency controls. alpha, beta, delta and gamma parameters as described in Tauris & van den Heuvel 2006 section 16.4.1, transfer efficiency is given by 1-alpha-beta-delta.
These only affect mass that is lost from the donor due to mass transfer, winds from each star will carry away angular momentum from the vicinity of each even when transfer efficiency is unity. Each of these represent the following:
alpha : fraction of mass lost from the vicinity of the donor as fast wind
beta : fraction of mass lost from the vicinity of the accretor as fast wind
delta : fraction of mass lost from circumbinary coplanar toroid
gamma : radius of the circumbinary coplanar toroid is
gamma**2 * orbital_separation
mass_transfer_alpha = 0.0d0
mass_transfer_beta = 0.0d0
mass_transfer_delta = 0.0d0
mass_transfer_gamma = 0.0d0
limit_retention_by_mdot_edd
Limit accretion using mdot_edd
. The current implementation is intended for use with
black hole accretors, as in e.g. Podsiadlowski, Rappaport & Han (2003), MNRAS, 341, 385.
For other accretors mdot_edd
should be set with use_this_for_mdot_edd
, the hook
use_other_mdot_edd
, or by appropriately setting use_this_for_mdot_edd_eta
.
Note: MESA versions equal or lower than 8118 used eta=1 and did not correct
the accreted mass for the energy lost by radiation.
If accreted material radiates an amount of energy equal to L=eta*mtransfer_rate*clight**2
,
then accretion is assumed to be limited to the Eddington luminosity,
Ledd = 4*pi*cgrav*Mbh*clight/kappa
which results in the Eddington mass-accretion rate
mdot_edd = 4*pi*cgrav*Mbh/(kappa*clight*eta)
the efficiency eta is determined by the properties of the last stable circular orbit, and for a BH with no initial spin it can be expressed in terms of the initial BH mass Mbh0 and the current BH mass,
eta = 1-sqrt(1-(Mbh/(3*Mbh0))**2)
for Mbh < sqrt(6) Mbh0. For BHs with initial spins different from zero, an effective Mbh0 can be computed, corresponding to the mass the black hole would have needed to have with zero spin to reach the current mass and spin.
limit_retention_by_mdot_edd = .false.
use_es_opacity_for_mdot_edd
If .true., then the opacity for mdot_edd
is computed as 0.2*(1+X)
If .false., the opacity of the outermost cell of the donor is used
use_es_opacity_for_mdot_edd = .true.
use_this_for_mdot_edd_eta
Fixed mdot_edd_eta
, if negative, eta will be computed consistently as material is accreted.
Values should be between ~0.06-0.42, the minimum corresponding to a BH with spin parameter a=0, and the maximum to a=1.
use_this_for_mdot_edd_eta = -1
use_radiation_corrected_transfer_rate
If true, then reduce the increase in mass of the BH to account for the radiated energy eta*mtransfer_rate_clight**2
so that in a timestep
delta_Mbh = (1-eta)*mass_transfer_rate*dt
use_radiation_corrected_transfer_rate = .true.
initial_bh_spin
Initial spin parameter of the black hole “a”. Must be between 0 and 1. Evolution of BH spin is done with eq. (6) of King & Kolb (1999), MNRAS, 305, 654
initial_bh_spin = 0
use_this_for_mdot_edd
Fixed mdot_edd
in Msun/yr, ignored if negative
use_this_for_mdot_edd = -1
mdot_scheme
How to compute mass transfer. Options are:
“Ritter” : Ritter 1988, A&A, 202, 93
“Kolb” : Optically thick overflow of Kolb & Ritter 1990, A&A, 236, 385
- “roche_lobe”Set mass transfer rate such that the donor remains inside
its Roche lobe. Only works implicitly.
- “contact”Extends the roche_lobe scheme to include contact systems as in
Marchant et al. (2016), A&A, 588, A50
mdot_scheme = 'Ritter'
explicit mass transfer computation.
MESA can compute mass transfer rates either explicitly (at the beggining
of the step) or implicitly (iterating the solution until the mass transfer
rate matches the value computed at the end of the step). The explicit method
is used if max_tries_to_achieve <= 0
.
cur_mdot_frac
Average the explicit mass transfer rate computed with the old in order to smooth large changes.
mass_transfer = mass_transfer_old * cur_mdot_frac + (1-cur_mdot_frac) * mass_transfer
cur_mdot_frac = 0.5d0
max_explicit_abs_mdot
Limit the explicit mass transfer rate to max_explicit_abs_mdot
, in Msun/secyer
max_explicit_abs_mdot = 1d-7
implicit mass transfer computation.
max_tries_to_achieve
The implicit method will modify the mass transfer rate and redo the step until
it either finds a solution, or the number of tries goes above max_tries_to_achieve
.
if max_tries_to_achieve <= 0
the explicit method is used.
max_tries_to_achieve = 20
solver_type
Method use to solve for mass transfer. The solver first attempts to increase or reduce the mass transfer rate used through the step until finding an upper and lower limit to it. This controls what is done after that point. Options are:
- “cubic”Given an upper and lower limit, plus a new try in between,
the root of the equation is estimated by using a cubic matching the three points.
“bisect” : Simply takes the average of the boundaries for the next try
“both” : Alternates between cubic and bisect each iteration
solver_type = 'both'
implicit_scheme_tolerance
Tolerance for which a solution is considered valid. For the Ritter and Kolb schemes if we call mdot the mass transfer rate used for the step, and mdot_end the one computed at the end of it, a solution is valid if
abs((mdot-mdot_end)/mdot_end) < b% implicit_scheme_tolerance
For the roche_lobe scheme, a solution will be considered valid if
-implicit_scheme_tolerance < (r-rl)/rl < 0
When using the roche_lobe scheme smaller values of order 1d-3 or smaller are recommended.
implicit_scheme_tolerance = 1d-2
implicit_scheme_tiny_factor
During the implicit scheme the solution is bracketed between a minimum and a maximum value mdot_hi and mdot_lo. Even if the desired tolerance is not achieved, the solution is accepted if the difference between abs(mdot_hi-mdot_lo) is smaller than implicit_scheme_tiny_factor*min(abs(mdot_hi),abs(mdot_lo))
implicit_scheme_tiny_factor = 1d-6
initial_change_factor
change_factor_fraction
implicit_lambda
The implicit scheme works by adjusting the mass transfer rate from the previous
step until it finds a solution. If the mass transfer needs to increase/reduce after
a try, then it is multiplied/divided by change_factor
. initial_change_factor
provides
the initial value for this parameter, however, since at certain points the mass
transfer rate will increase steeply and at others remain mostly constant from step
to step, MESA adjusts the value of the change factor to make it easier to find
solutions. Whenever the mass transfer rate changes from the previous value, MESA
will modify the change_factor
according to:
if(mass_transfer_rate < mass_transfer_prev) then
change_factor = change_factor*(1.0-implicit_lambda) &
+ implicit_lambda*(1+change_factor_fraction*(mass_transfer_rate/mass_transfer_prev-1))
else
change_factor = change_factor*(1.0-implicit_lambda) &
+ implicit_lambda*(1+change_factor_fraction*(mass_transfer_prev/mass_transfer_rate-1))
end if
Choosing implicit_lambda = 0
will keep the change factor constant.
initial_change_factor = 1.5d0
change_factor_fraction = 0.9d0
implicit_lambda = 0.25d0
max_change_factor
min_change_factor
Maximum and minimum values for the change_factor
max_change_factor = 1.5d0
min_change_factor = 1.05d0
num_tries_for_increase_change_factor
change_factor_increase
If after every num_tries_for_increase_change_factor
iterations the implicit scheme does not have upper
and lower bounds for the mass transfer rate, multiply change_factor
by change_factor_increase
. Ignored if
num_tries_for_increase_change_factor < 1
. Increase is limited to max_change_factor
.
num_tries_for_increase_change_factor = 20
change_factor_increase = 1.1d0
starting_mdot
When using the roche_lobe
scheme, if the donor overflows for the first time
use starting_mdot
(in Msun/secyer) as an initial guess for the mass transfer rate.
starting_mdot = 1d-12
roche_min_mdot
When using the roche_lobe
scheme, if mass transfer rate is below roche_min_mdot
(in Msun/secyer) and the donor is not overflowing its roche lobe, assume detachment
and stop mass transfer.
roche_min_mdot = 1d-16
min_mdot_for_implicit
For any choice except for the roche_lobe
scheme mass transfer will be computed explicitly
until the explicit computation of mdot is > min_mdot_for_implicit
(in Msun/secyer),
even if max_tries_to_achieve
> 0. This is to avoid spending many iterations when the stars
are detached and the explicit calculation gives very low values of mdot.
min_mdot_for_implicit = 1d-16
max_implicit_abs_mdot
Limit the implicit mass transfer rate to max_implicit_abs_mdot
, in Msun/secyer
max_implicit_abs_mdot = 1d99
report_rlo_solver_progress
Set true to see info about the iterations to compute mass transfer from RLOF
report_rlo_solver_progress = .false.
Tidal wind enhancement
do_enhance_wind_*
Use the Tout & Eggleton mechanism to tidally enhance the wind mass loss from one or both components according to:
Mdot_w = Mdot_w * ( 1 + B_wind * min( (R/RL)^6, 0.5^6 ) )
Tout & Eggleton 1988,MNRAS,231,823 (eq. 2)
“_1” refers to first star, “_2” to the second one.
do_enhance_wind_1 = .false.
do_enhance_wind_2 = .false.
tout_B_wind_*
The B_wind
parameter from the previous equation. Default value is
taken from Tout & Eggleton 1988,MNRAS,231,823
“_1” refers to first star, “_2” to the second one.
tout_B_wind_1 = 1d4
tout_B_wind_2 = 1d4
Wind mass accretion
do_wind_mass_transfer_*
transfer part of the mass lost due to stellar winds from the mass losing component to its companion. Using the Bondi-Hoyle mechanism. “_1” refers to first star, “_2” to the second one.
do_wind_mass_transfer_1 = .false.
do_wind_mass_transfer_2 = .false.
wind_BH_alpha_*
Bondi-Hoyle accretion parameter for each star. The default for alpha is 3/2 taken from Hurley et al. 2002, MNRAS, 329, 897, in agreement with Boffin & Jorissen 1988, A&A, 205, 155. The default for beta is 1/8=0.125 in accordance for results of cool supergiants from Kucinskas A., 1999, Ap&SS, 262, 127 “_1” refers to first star, “_2” to the second one.
wind_BH_alpha_1 = 1.5d0
wind_BH_alpha_2 = 1.5d0
wind_BH_beta_1 = 1.25d-1
wind_BH_beta_2 = 1.25d-1
max_wind_transfer_fraction_*
Upper limit on the wind transfer fraction for star * “_1” refers to first star, “_2” to the second one.
max_wind_transfer_fraction_1 = 0.5d0
max_wind_transfer_fraction_2 = 0.5d0
orbital jdot controls
do_jdot_gr
Include gravitational wave radiation in jdot
do_jdot_gr = .true.
do_jdot_ml
Include loss of angular momentum via mass loss. The parameters
mass_transfer_*
determine the fractions of mass lost from the vincinity
of the donor, the accretor, or a circumbinary coplanar toroid.
do_jdot_ml = .true.
do_jdot_ls
Fix jdot such that the total angular momentum of the system is conserved, except for loses due to other jdot mechanisms, or angular momentum loss from winds. This is meant to take care of L-S coupling due to tides.
do_jdot_ls = .true.
do_jdot_missing_wind
Usually MESA computes stellar AM loss due to winds by taking the angular momentum from
the removed layers of the star. However, when mass transfer is included, wind mass
loss and mass accretion are added up, and only the remainder, if corresponding to
net mass loss, contributes to stellar AM loss. jdot_missing_wind
compensates for this,
by removing from the orbit an amount of angular momentum equal to the mass lost
that does not contribute to stellar AM loss, times the specific angular momentum
at the surface.
do_jdot_missing_wind = .false.
do_jdot_mb
Include magnetic braking as in Rappaport, Verbunt, and Joss. apj, 275, 713-731. 1983.
do_jdot_mb = .true.
include_accretor_mb
If true, the contribution to jdot from magnetic braking of the accretor is also taken into account.
include_accretor_mb = .false.
magnetic_braking_gamma
gamma exponent for magnetic braking.
magnetic_braking_gamma = 3.0d0
keep_mb_on
If true keep magnetic braking even when radiative core goes away.
keep_mb_on = .false.
jdot_mb_min_qconv_env
jdot_mb_max_qconv_env
jdot_mb_max_qconv_core
jdot_mb_qlim_for_check_rad_core
jdot_mb_qlim_for_check_conv_env
Conditions for magnetic braking to operate. Magnetic braking is turned off if any of these do not apply. The mass fraction of the convective envelope has to be > jdot_mb_min_qconv_env. The mass fraction of the convective envelope has to be < jdot_mb_max_qconv_env. The mass fraction of the convective core has to be < jdot_mb_max_qconv_core. Here by mass fraction we refer to the mass of the respective zone divided by the total mass of the star. To compute the mass in the envelope we add all convective layers down to jdot_mb_qlim_for_check_conv_env, and keep adding layers downwards until we reach a non-convective zone. This is because the very outermost cell is likely radiative. A similar thing is done for the core with jdot_mb_qlim_for_check_rad_core. For full details check binary_jdot.f90.
jdot_mb_min_qconv_env = 1d-6
jdot_mb_max_qconv_env = 0.99d0
jdot_mb_max_qconv_core = 1d-2
jdot_mb_qlim_for_check_rad_core = 1d-3
jdot_mb_qlim_for_check_conv_env = 0.999d0
jdot_mb_scale_for_low_qconv_env
jdot_mb_mass_frac_for_scale
If jdot_mb_scale_for_low_qconv_env is .true., scale down jdot_mb if mass fraction of the convective envelope is below jdot_mb_mass_frac_for_scale. (Podsiadlowski et al. 2002, The Astrophysical Journal, Volume 565, Issue 2, pp. 1107-1133)
jdot_mb_scale_for_low_qconv_env = .true.
jdot_mb_mass_frac_for_scale = 0.02d0
jdot_multiplier
Multiply total jdot by this factor.
NOTE: jdot_ls
is not affected by this.
jdot_multiplier = 1d0
rotation and sync controls
do_j_accretion
If true, compute accretion of angular momentum following A.3.3 of de Mink et al. 2013, ApJ, 764, 166. Otherwise, incoming material is assumed to have the specific angular momentum of the surface of the accretor.
do_j_accretion = .false.
do_tidal_sync
If true, apply tidal torque to the star
do_tidal_sync = .false.
sync_type_*
Timescale for orbital synchronisation. “_1” refers to first star, “_2” to the second one. Options are:
“Instantaneous” : Keep the star synced to the orbit.
“Orb_period” : Sync in the timescale of the orbital period.
- “Hut_conv”Sync timescale following Hurley et al. 2002, MNRAS, 329, 897
for convective envelopes.
- “Hut_rad”Sync timescale following Hurley et al. 2002, MNRAS, 329, 897
for radiative envelopes.
“None” : No sync for this star.
sync_type_1 = 'Hut_conv'
sync_type_2 = 'Hut_conv'
sync_mode_*
Where angular momentum is deposited for synchronization. “_1” refers to first star, “_2” to the second one. Options are:
“Uniform” : Each layer is synced independently given the sync timescale.
sync_mode_1 = 'Uniform'
sync_mode_2 = 'Uniform'
Ftid_*
Tidal strength factor. Synchronisation and circularisation timescales are divided by this. “_1” refers to first star, “_2” to the second one.
Ftid_1 = 1d0
Ftid_2 = 1d0
do_initial_orbit_sync_*
Relax rotation of star to orbital period at the beggining of evolution. “_1” refers to first star, “_2” to the second one.
do_initial_orbit_sync_1 = .false.
do_initial_orbit_sync_2 = .false.
tidal_reduction
tidal_reduction
accounts for the reduction in the effectiveness of convective
damping of the equilibrium tide when the tidal forcing period is less than the
convective turnover period of the largest eddies. It corresponds to the exponent
in eq. (32) of Hurley et al. 2002, MNRAS, 329, 897
tidal_reduction
= 1 follows Zahn(1966, 1989), while tidal_reduction
= 2 follows
Goldreich & Nicholson (1977).
tidal_reduction = 2.0d0
eccentricity controls
do_tidal_circ
If true, apply tidal circularisation
do_tidal_circ = .false.
circ_type_*
Mechanism for circularisation. Options are: “_1” refers to first star, “_2” to the second one.
- “Hut_conv”Circ timescale following Hurley et al. 2002, MNRAS, 329, 897
for convective envelopes.
- “Hut_rad”Circ timescale following Hurley et al. 2002, MNRAS, 329, 897
for radiative envelopes.
“None” : no tidal circularisation
circ_type_1 = 'Hut_conv'
circ_type_2 = 'Hut_conv'
use_eccentricity_enhancement
Flag to turn on Soker eccentricity enhancement
use_eccentricity_enhancement = .false.
max_abs_edot_tidal
Maximum absolute value for tidal edot (in 1/s). If the computed tidal edot goes above this, then it is fixed at this maximum
max_abs_edot_tidal = 1d-6
max_abs_edot_enhance
Maximum absolute value for eccentricity enhancement (in 1/s). If the computed edot goes above this, then it is fixed at this maximum
max_abs_edot_enhance = 1d-6
min_eccentricity
If after a step eccentricity < min_eccentricity
, then fix it at this value
min_eccentricity = 0.0d0
max_eccentricity
If after a step eccentricity > max_eccentricity
, then fix it at this value
max_eccentricity = 0.99d0
anomaly_steps
For phase dependent processes, the orbit is divided into this number of steps in the true anomaly, to integrate through a full orbit and obtain the secular changes
anomaly_steps = 500
irradiation controls
accretion_powered_irradiation
Flag to turn on irradiation of the donor due to accretion onto a compact object.
accretion_powered_irradiation = .false.
col_depth_for_eps_extra
Energy from irradiation will be deposited in the outer
4*Pi*R^2*col_depth_for_eps_extra
grams of the star.
col_depth_for_eps_extra = -1
use_accretor_luminosity_for_irrad
Flag to turn on irradiation based on the luminosity of the accretor and binary
separation. Requires evolve_both_stars = .true.
in binary_job inlist.
use_accretor_luminosity_for_irrad = .false.
irrad_flux_at_std_distance
std_distance_for_irradiation
If irrad_flux_at_std_distance > 0
then irradiation flux is computed as
s% irradiation_flux = b% irrad_flux_at_std_distance * &
(b% std_distance_for_irradiation/b% separation)**2
irrad_flux_at_std_distance = -1
std_distance_for_irradiation = -1
max_F_irr
Limit irradiation by this amount.
max_F_irr = 5d12
common envelope controls (EXPERIMENTAL, DON’T USE)
CE_alpha
Common envelope efficiency factor
CE_alpha = 1d0
CE_alpha_th
Common envelope thermal efficiency factor
CE_alpha_th = 1d0
CE_alpha_core
Efficiency at which the change of energy in the core of the star contributes to envelope ejection.
CE_alpha_core = 0d0
CE_mass_loss_rate_high
Upper mass loss rate imposed during CE in Msun/yr
CE_mass_loss_rate_high = 1d-1
CE_mass_loss_rate_low
Lower mass loss rate imposed during CE in Msun/yr
CE_mass_loss_rate_low = 1d-6
CE_rel_rlo_for_detachment
Consider the CE phase terminated when (r-rl)/rl < -CE_rel_rlo_for_detachment Between (r-rl)/rl = 0d0 and (r-rl)/rl = -CE_rel_rlo_for_detachment the mass loss rate is adjusted between CE_mass_loss_rate_high and CE_mass_loss_rate_low.
CE_rel_rlo_for_detachment = 0.02d0
CE_years_detached_to_terminate
During CE, if the star spends this amount of time detached, terminate CE even if CE_rel_rlo_for_detachment has not been reached. If set to a large number mass loss will only stop when the star definetely wants to detach. If set to a low number system will likely switch to stable mass transfer.
CE_years_detached_to_terminate = 1d-1
CE_begin_at_max_implicit_abs_mdot
If true, initiate a common envelope phase when max_implicit_abs_mdot is reached
CE_begin_at_max_implicit_abs_mdot = .false.
CE_xa_diff_to_terminate
If the absolute difference between central and surface mass fractions of H and He is below this, terminate the simulation. This is to stop the simulation once the entire envelope has been removed
CE_xa_diff_to_terminate = 0.01d0
CE_terminate_when_core_overflows
Terminate if, for the current orbital separation, the radius at the point where CE_xa_diff_to_terminate applies would overflow its Roche lobe
CE_terminate_when_core_overflows = .true.
CE_min_period_in_days
Terminate the simulation if the period is below this during CE used to terminate the simulation early in cases where a merger would be expected.
CE_min_period_in_minutes = 5d0
CE_energy_factor_HII_toHI
Recombination energy for ionized hydrogen will be multiplied by this factor when computing the energy.
CE_energy_factor_HII_toHI = 1d0
CE_energy_factor_HeII_toHeI
Recombination energy for singly ionized helium will be multiplied by this factor when computing the energy.
CE_energy_factor_HeII_toHeI = 1d0
CE_energy_factor_HeIII_toHeII
Recombination energy for doubly ionized helium will be multiplied by this factor when computing the energy.
CE_energy_factor_HeIII_toHeII = 1d0
CE_energy_factor_H2
Dissociation energy for molecular hydrogen will be multiplied by this factor when computing the energy.
CE_energy_factor_H2 = 0d0
CE_fixed_lambda
For comparison to rapid-pop-synth, if this is larger than zero, then compute the binding energy from this value of lambda rather than by integrating through the envelope
CE_fixed_lambda = -1d0
miscellaneous controls
keep_donor_fixed
keep star 1 as donor, even if accretor is closer to filling roche lobe
keep_donor_fixed = .true.
mdot_limit_donor_switch
Do not change donor if mass transfer is larger than this (given in Msun/secyer). Avoids erratic changes when both stars are filling their roche loches.
mdot_limit_donor_switch = 1d-20
use_other_{hook}
Logicals to deploy the use_other routines.
use_other_rlo_mdot = .false.
use_other_check_implicit_rlo = .false.
use_other_implicit_function_to_solve = .false.
use_other_tsync = .false.
use_other_sync_spin_to_orbit = .false.
use_other_mdot_edd = .false.
use_other_adjust_mdots = .false.
use_other_accreted_material_j = .false.
use_other_jdot_gr = .false.
use_other_jdot_ml = .false.
use_other_jdot_ls = .false.
use_other_jdot_missing_wind = .false.
use_other_jdot_mb = .false.
use_other_extra_jdot = .false.
use_other_binary_wind_transfer = .false.
use_other_edot_tidal = .false.
use_other_edot_enhance = .false.
use_other_extra_edot = .false.
use_other_CE_init = .false.
use_other_CE_rlo_mdot = .false.
use_other_CE_binary_evolve_step = .false.
use_other_CE_binary_finish_step = .false.
use_other_e2 = .false.
extra params as a convenience for developing new features
note: the parameter num_x_ctrls
is defined in binary_def.f90
x_ctrl(1:binary_num_x_ctrls) = 0d0
x_integer_ctrl(1:binary_num_x_ctrls) = 0
x_logical_ctrl(1:binary_num_x_ctrls) = .false.
x_character_ctrl(1:binary_num_x_ctrls) = ''