POSDYON Population Synthesis Configuration Guide

This documentation provides a detailed overview of the configuration options available in the Posydon software package.

TODO: fill each table cell with a description of the parameter and the options

Environment Variables

The environment variable PATH_TO_POSYDON will be read from your shell session.

Parameter	Description/Value
PATH_TO_POSYDON	<PATH_TO_POSYDON>

SimulationProperties

TODO: add description

Flow Chart

The flow chart is the core of POSYDON. It controls the mapping between a POSYDON binary object and its step evolution, see the Flow Chart Object page for more details.

Parameter	Description/Value
import	[‘posydon.binary_evol.flow_chart’, ‘flow_chart’]
absolute_import = None	‘package’ (kwarg for importlib.import_module)

Step MESA (HMS-HMS, CO-HMS_RLO, CO-HeMS, CO-HeMS_RLO)

The MESA step is the most important step of POSYDON as it leverages the POSYDON MESA grids to evolve the binary object according to one of the supported MESA binary-star grids.

Parameter	Description/Value
import	[‘posydon.binary_evol.MESA.step_mesa’, ‘MS_MS_step’]
absolute_import = None	‘package’ (kwarg for importlib.import_module)
interpolation_path	None (found by default)
interpolation_filename	None (found by default)
interpolation_method	‘1NN_1NN’ (‘nearest_neighbour’, ‘linear3c_kNN’, ‘1NN_1NN’ are options)
save_initial_conditions	True (only for interpolation_method=’nearest_neighbour’)
track_interpolation	False
stop_method	‘stop_at_max_time’ (‘stop_at_end’, ‘stop_at_max_time’, ‘stop_at_condition’ are options)
stop_star	‘star_1’ (only for stop_method=’stop_at_condition’, ‘star_1’ and ‘star_2’ are options)
stop_var_name	None (only for stop_method=’stop_at_condition’, string)
stop_value	None (only for stop_method=’stop_at_condition’, float)
stop_interpolate	True
verbose	False

Step Detached

TODO: add description

Parameter	Description/Value
import	[‘posydon.binary_evol.DT.step_detached’, ‘detached_step’]
absolute_import	None (‘package’ kwarg for importlib.import_module)
matching_method	‘minimize’ (options ‘minimize’ ‘root’)
do_wind_loss	True
do_tides	True
do_gravitational_radiation	True
do_magnetic_braking	True
do_stellar_evolution_and_spin_from_winds	True
RLO_orbit_at_orbit_with_same_am	False
verbose	False

Step Disrupted

TODO: add description

Parameter	Description/Value
import	[‘posydon.binary_evol.DT.step_disrupted’,’DisruptedStep’]

Step Merged

TODO: add description

Parameter	Description/Value
import	[‘posydon.binary_evol.DT.step_merged’,’MergedStep’]

Step Initially Single

TODO: add description

Parameter	Description/Value
import	[‘posydon.binary_evol.DT.step_initially_single’,’InitiallySingleStep’]

Step Common Envelope

TODO: add description

Parameter	Description/Value
import	[‘posydon.binary_evol.CE.step_CEE’, ‘StepCEE’]
absolute_import	None(‘package’ kwarg for importlib.import_module)
prescription	‘alpha-lambda’
common_envelope_efficiency	1.0 (float in [0, inf])
common_envelope_option_for_lambda	‘lambda_from_grid_final_values’ (options are: (1) ‘default_lambda’, (2) ‘lambda_from_grid_final_values’, (3) ‘lambda_from_profile_gravitational’, (4) ‘lambda_from_profile_gravitational_plus_internal’, (5) ‘lambda_from_profile_gravitational_plus_internal_minus_recombination’)
common_envelope_lambda_default	0.5 (float in [0, inf] used only for option (1))
common_envelope_option_for_HG_star	‘optimistic’ (options are ‘optimistic’, ‘pessimistic’)
common_envelope_alpha_thermal	1.0 (float in [0, inf] used only for option for (4), (5))
core_definition_H_fraction	0.1 (options are 0.01, 0.1, 0.3)
core_definition_He_fraction	0.1
CEE_tolerance_err	0.001 (float in [0, inf])
common_envelope_option_after_succ_CEE	‘core_not_replaced_noMT’ (options are ‘core_not_replaced_noMT’ ‘core_replaced_noMT’, ‘core_not_replaced_stableMT’ ‘core_not_replaced_windloss’)
verbose	False

Step Supernova

TODO: add description

Parameter	Description/Value
import	[‘posydon.binary_evol.SN.step_SN’, ‘StepSN’]
absolute_import	None (‘package’ kwarg for importlib.import_module)
mechanism	‘Patton&Sukhbold20-engine’ (options are: ‘direct’, Fryer+12-rapid’, ‘Fryer+12-delayed’, ‘Sukhbold+16-engine’, ‘Patton&Sukhbold20-engine’)
engine	‘N20’ (options are ‘N20’ for ‘Sukhbold+16-engine’, ‘Patton&Sukhbold20-engine’ or None for the others)
PISN	‘Marchant+19’ (options are None, “Marchant+19”)
ECSN	“Podsiadlowksi+04” (options are “Tauris+15”, “Podsiadlowksi+04”)
conserve_hydrogen_envelope	True
max_neutrino_mass_loss	0.5 (float in [0,inf])
max_NS_mass	2.5 (float in [0,inf])
use_interp_values	True
use_profiles	True
use_core_masses	True
approx_at_he_depletion	False
kick	True
kick_normalisation	‘one_over_mass’ (options are “one_minus_fallback”, “one_over_mass”, “NS_one_minus_fallback_BH_one”, “one”, “zero”)
sigma_kick_CCSN_NS	265.0 (float in [0,inf])
sigma_kick_CCSN_BH	265.0 (float in [0,inf])
sigma_kick_ECSN	20.0 (float in [0,inf])
verbose	False

Step Double Compact Object

TODO: add description

Parameter	Description/Value
import	[‘posydon.binary_evol.DT.double_CO’, ‘DoubleCO’]
absolute_import	None (‘package’ kwarg for importlib.import_module)
n_o_steps_interval	None

Step End

TODO: add description

Parameter	Description/Value
import	[‘posydon.binary_evol.step_end’, ‘step_end’]
absolute_import	None (‘package’ kwarg for importlib.import_module)

Extra Hooks

TODO: add description

Parameter	Description/Value
import	[‘posydon.binary_evol.simulationproperties’, ‘TimingHooks’]
absolute_import_1	None
kwargs_1	{}
import	[‘posydon.binary_evol.simulationproperties’, ‘StepNamesHooks’]
absolute_import_2	None
kwargs_2	{}

BinaryPopulation

TODO: add description

BinaryPopulation Options

TODO: add description

Parameter	Description/Value
optimize_ram	True (save population in batches)
ram_per_cpu	None (set maximum ram per cpu before batch saving in GB)
dump_rate	1000 (batch save after evolving N binaries)
temp_directory	‘batches’ (folder for keeping batch files)
tqdm	False (progress bar)
breakdown_to_df	True (convert BinaryStars into DataFrames after evolution)
use_MPI	True ( if True evolve with MPI, equivalent to the following: from mpi4py import MPI, comm = MPI.COMM_WORLD)
metallicity	[2., 1., 0.45, 0.2, 0.1, 0.01, 0.001, 0.0001] (In units of solar metallicity)
entropy	None (Random Number Generation: uses system entropy (recommended))
number_of_binaries	1000000 (int)
star_formation	‘burst’ (options are ‘constant’ ‘burst’ ‘custom_linear’ ‘custom_log10’ ‘custom_linear_histogram’ ‘custom_log10_histogram’)
max_simulation_time	13.8e9 (float in [0,inf])
binary_fraction	1 (float 0< fraction <=1)
primary_mass_scheme	‘Kroupa2001’ (options are ‘Salpeter’, ‘Kroupa1993’, ‘Kroupa2001’)
primary_mass_min	6.5 (float in [0,300])
primary_mass_max	250.0 (float in [0,300])
secondary_mass_scheme	‘flat_mass_ratio’ (options are ‘flat_mass_ratio’, ‘q=1’)
secondary_mass_min	0.35 (float in [0,300])
secondary_mass_max	250.0 (float in [0,300])
orbital_scheme`	‘period’ (options are ‘separation’, ‘period’)
orbital_period_scheme	‘Sana+12_period_extended’ (used only for orbital_scheme = ‘period’)
orbital_period_min	0.75 (float i [0,inf])
orbital_period_max	6000.0 (float i [0,inf])
#orbital_separation_scheme	‘log_uniform’ (used only for orbital_scheme = ‘separation’, ‘log_uniform’, ‘log_normal’)
#orbital_separation_min	5.0 (float i [0,inf])
#orbital_separation_max	1e5 (float i [0,inf])
#log_orbital_separation_mean	None (float i [0,inf] used only for orbital_separation_scheme =’log_normal’)
#log_orbital_separation_sigma	None (float i [0,inf] used only for orbital_separation_scheme =’log_normal’)
eccentricity_scheme	‘zero’ (options are ‘zero’, ‘thermal’, ‘uniform’)

Saving Output

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BinaryStar Output

TODO: add description

Parameter

Description/Value

extra_columns

{‘step_names’:’string’, ‘step_times’:’float64’} (‘step_times’ with from posydon.binary_evol.simulationproperties import TimingHooks)

only_select_columns

[‘state’, ‘event’, ‘time’, ‘orbital_period’, ‘eccentricity’, ‘lg_mtransfer_rate’] (all options: ‘state’, ‘event’, ‘time’, ‘separation’, ‘orbital_period’, ‘eccentricity’, ‘V_sys’, ‘rl_relative_overflow_1’, ‘rl_relative_overflow_2’, ‘lg_mtransfer_rate’, ‘mass_transfer_case’, ‘trap_radius’, ‘acc_radius’, ‘t_sync_rad_1’, ‘t_sync_conv_1’, ‘t_sync_rad_2’, ‘t_sync_conv_2’, ‘nearest_neighbour_distance’)

SingleStar 1 and 2 Output

TODO: add description

Parameter	Description/Value
include_S1	True
only_select_columns	[‘state’, ‘mass’, ‘log_R’, ‘log_L’, ‘lg_mdot’, ‘he_core_mass’, ‘he_core_radius’, ‘co_core_mass’, ‘co_core_radius’, ‘center_h1’, ‘center_he4’, ‘surface_h1’, ‘surface_he4’, ‘surf_avg_omega_div_omega_crit’, ‘spin’,] (options are: ‘state’, ‘metallicity’, ‘mass’, ‘log_R’, ‘log_L’, ‘lg_mdot’, ‘lg_system_mdot’, ‘lg_wind_mdot’, ‘he_core_mass’, ‘he_core_radius’, ‘c_core_mass’, ‘c_core_radius’, ‘o_core_mass’, ‘o_core_radius’, ‘co_core_mass’, ‘co_core_radius’, ‘center_h1’, ‘center_he4’, ‘center_c12’, ‘center_n14’, ‘center_o16’, ‘surface_h1’, ‘surface_he4’, ‘surface_c12’, ‘surface_n14’, ‘surface_o16’, ‘log_LH’, ‘log_LHe’, ‘log_LZ’, ‘log_Lnuc’, ‘c12_c12’, ‘center_gamma’, ‘avg_c_in_c_core’, ‘surf_avg_omega’, ‘surf_avg_omega_div_omega_crit’, ‘total_moment_of_inertia’, ‘log_total_angular_momentum’, ‘spin’, ‘conv_env_top_mass’, ‘conv_env_bot_mass’, ‘conv_env_top_radius’, ‘conv_env_bot_radius’, ‘conv_env_turnover_time_g’, ‘conv_env_turnover_time_l_b’, ‘conv_env_turnover_time_l_t’, ‘envelope_binding_energy’, ‘mass_conv_reg_fortides’, ‘thickness_conv_reg_fortides’, ‘radius_conv_reg_fortides’, ‘lambda_CE_1cent’, ‘lambda_CE_10cent’, ‘lambda_CE_30cent’, ‘lambda_CE_pure_He_star_10cent’, ‘profile’)
scalar_names	[ ‘natal_kick_array’, ‘SN_type’, ‘f_fb’, ‘spin_orbit_tilt’, ‘m_disk_accreted’, ‘m_disk_radiated’]