This is a basic reproduction package for the paper "BH-BH mergers with & without EM counterpart: A model for stable tertiary mass transfer in hierarchical triple systems" by Kummer et al. (2024).
To run the scripts in this package, the following software has been used:
The data.tar.gz
package contains all the data files necessary for producing intermediate and final products of the paper.
This package contains the following data:
data_orig
: This directory contains the sample of all simulated triple star systems relevant for this project. The directory contains the following folders and files:
lum_rd_pop_z0d005_test
& lum_rdc_pop_z0d005_test_extended_a_out
: Evolutionary data of individual triple star systems that evolve chemically homogeneous with metallicity Z=0.005 from the ZAMS up to the moment of interaction.lum_rd_pop_z0d0005_test
: Evolutionary data of individual triple star systems that evolve chemically homogeneous with metallicity Z=0.0005 from the ZAMS up to the moment of interaction .Collect_TMT.py
: Filters and saves the systems that undergo TMT with a BHBH inner binary.input_data_lum_z0d005.csv
: File produced by running Collect_TMT.py and used as input for the mass transfer scripts.input_data_lum_z0d0005.csv
: File produced by running Collect_TMT.py and used as input for the mass transfer scripts.data_siwek2023
: This directory contains orbital evolution parameters of a binary surrounded by a CBD which are used in the model. The data originates from Siwek et al. (2023).
data_example_system
: This directory contains output data for the example system discussed in Section 4 of the paper.
data_models
: This directory contains output data for the population of triple stars discussed in Section 5 of the paper. The metallicity of the population has been denoted in the filenames by Z005 or Z0005, corresponding to Z=0.005 and Z=0.0005, respectively. The high_density files refer to a gas density of 10^-8 g/cm^3 and nuclear mass transfer rate. The low_density files refer to a gas density of 10^-10 g/cm^3 and thermal mass transfer rate. The thermal_high_density files refer to a gas density of 10^-8 g/cm^3 and thermal mass transfer rate. The nuclear_low_density files refer to a gas density of 10^-10 g/cm^3 and nuclear mass transfer rate.
The scripts.tar.gz
package contains the python scripts that simulates the TMT phase and calculates the merger rates of BHBH mergers.
TMT_model_example.py
: This script calculates the orbital evolution of an example system during TMT. Creates output files in the data_example_system directory.
TMT_model.py
: This script calculates the orbital evolution for a set of input systems during TMT. Creates output files in the data_models directory.
TMT_model_GW.py
: This script calculates the orbital evolution for a set of input systems during TMT and the ensuing gravitational-wave inspiral. Creates output files in the data_models directory.
merger_rate_density.py
: This script calculates the merger rate of the BHBH systems simulated with the TMT model and is used to reproduce Figure 9 and obtain the data in Table A.2 of the paper.
Almost all the options for running the TMT models can be found at the end of the files.
TMT_model.py
and TMT_model_GW.py
need an input file. By default this is the ../data/data_orig/input_data_lum_z0d005.csv
file, but can also be replaced by ../data/data_orig/input_data_lum_z0d0005.csv
.
The output filename can be set in the print_systems()
function.
When running the script from the command line, various arguments can be passed along. We give an overview of the options:
--target_time
: total simulation time (default: 13.5 Gyr). Important that this is longer than the mass-transfer timescale--tau_mt
: Mass-transfer timescale (default: 'nuclear', options: ['nuclear', 'thermal'])--density
: Gas density during ballistic accretion (default: 10^-8 g/cm^3)--c_s
: Sound speed in gas during ballistic accretion (default: 3e6 cm/s)--include_cbd
: Allow formation of CBD (default: 'true', options: ['true', 'false'])--include_gdf
: Include gravitational drag forces (default: true, options: ['true', 'false'])--include_hydr
: Include hydrodynamic drag forces (default: true, options: ['true', 'false'])--outflow
: Type of mass outflow from inner binary during CBD (default: 'false', options: ['false', 'iso'])--ecc_GDF
: Eccentricity evolution during gas drag phase (default: 'false', options: ['false', 'true'])--I_GDF
: Prescription for the wake of the GDF (default: 'Ostriker99', options: ['Ostriker99', 'Kim08'])--retrograde
: Modified torques for retrograde CBDs (default: 'false', options: ['false', 'true'])By default, the script runs the Basic model. To run the different model variations presented in the paper, we include the following arguments:
Model Simple
: --include_cbd 'false'Model Basic+BinGDF
: --I_GDF 'Kim08'Model Basic+EccGDF
: --ecc_GDF 'true'Model Basic+Iso
: --outflow 'iso'Model Basic+Retro
: --retrograde 'true'Model Advanced
: --I_GDF 'Kim08' --ecc_GDF 'true' --outflow 'iso' --retrograde 'true'Model Basic+NoDrag
: --include_gdf 'false' --include_hydr 'false'Model Advanced+NoDrag
: --include_gdf 'false' --include_hydr 'false' --I_GDF 'Kim08' --ecc_GDF 'true' --outflow 'iso' --retrograde 'true'At the start of the System class, you can specificy whether your accretor is a compact object or not with the self.compact_object option, and in case you have the SeBa code installed with AMUSE, you can turn it on to determine the stability of the mass transfer with the self.use_seba option.
The figures.tar.gz
package contains jupyter notebooks that reproduce each figure and the tables with data from the paper (with the exclusion of Figures 1 & 3, which are cartoons).