Input files

Inputs to METISSE are provided using the following namelists:

1. SSE input controls

SSE_input_controls holds input parameters describing the initial conditions of the star and stellar populations. For the most up-to-date variable names and their default values refer to main_defaults.

Note

main.input is only read in METISSE’s standalone mode. When METISSE is used with other codes, the input parameters from the overlying code are used.

1.1. EVOLUTION CONTROLS

Variable name	Description
read_mass_from_file	If `.true.`, use initial masses listed in the `input_mass_file`. Default is `.false.`.
input_mass_file	Path to the input mass file if `read_mass_from_file = .true.`. List one mass value per line of the file.
number_of_tracks	Number of stars to be evolved. If `read_mass_from_file = .true.`, it denotes the number of mass values to be read from the `input_mass_file`.
max_mass	Upper limit of the uniform distribution if `read_mass_from_file = .false.` and `number_of_tracks` > 1
min_mass	Lower limit of the uniform distribution if `read_mass_from_file = .false.`
sampling_scheme	Sampling scheme for initial masses if `number_of_tracks` > 1. Options are: (1)“uniform” (2)“Kroupa2001” - Kroupa P. 2001 Default is “uniform”
initial_Z	Initial metallicity
max_age	Maximum age in Myrs

Note

To evolve a single star, set number_of_tracks = 1 and min_mass to the desired initial mass. In this case, max_mass is ignored.
To compute the evolution of a population of stars with uniformly distributed initial masses, use min_mass to set the lower limit of the distribution, max_mass for the upper limit, and number_of_tracks for the size of the population.

! EVOLUTION CONTROLS
read_mass_from_file = .false.     
input_mass_file = ''
number_of_tracks = 0
max_mass = -1.0
min_mass = -1.0
sampling_scheme = 'uniform'
initial_Z = -1.0
max_age = -1.0   

1.2. REMNANT CONTROLS

Variable name	Description
WD_mass_scheme	White Dwarf (WD) luminosity calculation method: (1) “Mestel” - Shapiro S. L., Teukolsky S. A., 1983 (2) “Modified_mestel” - Hurley J. R., Shara M. M., 2003 Default is “Modified_mestel”
use_initial_final_mass_relation	If `.true.` use the initial final mass relation for white dwarfs from Han, Z, Podsiadlowski, P., Eggleton, P. P. 1995. Default is `.false.`
BHNS_mass_scheme	Neutron Star/Black Hole (NS/BH) type and mass calculation method: (1) “original_SSE” - Hurley et al. 2000 (2) “Belczynski2002” - Belczynski et al. 2002 (3) “Belczynski2008” - Belczynski et al. 2008 (4) “Eldridge_Tout2004” - Eldridge J. J., Tout C. A., 2004 Default is “Belczynski2008”
max_NS_mass	Maximum neutron star mass. Recommended 1.8 for BHNS_mass_scheme = “original_SSE”, 3.0 otherwise. Default is 3.0
allow_electron_capture	Allow electron capture supernovae if `.true.` Default is `.true.`

! REMNANT CONTROLS 
WD_mass_scheme = 'Modified_mestel'
use_initial_final_mass_relation = .false.       
BHNS_mass_scheme = 'Belczynski2008'
max_NS_mass = 3.d0
allow_electron_capture = .true.  

1.3. TIMESTEP CONTROLS

Like SSE, METISSE uses pts variables to determine the timestep as the decimal fractions of the time spent in a phase.

Variable name	Description
pts_1	Determine timestep for 95% of MS, and HeMS. Default is 0.05
pts_2	Determine timestep for last 5% of MS, cHeBurn, HeHG, and HeGB. Default is 0.01
pts_3	Determine timestep for HG, RGB, EAGB, and TPAGB. Default is 0.02

! TIMESTEP CONTROLS
pts_1 = 0.05
pts_2 = 0.01
pts_3 = 0.02

1.4. OUTPUT CONTROLS

Variable name	Description
write_output_to_file	Generate a SSE-style file output file (file ending in .dat) at the END of the evolution. Default is `.false.`.

! OUTPUT CONTROLS
write_output_to_file = .false.

1.5. COLUMN CONTROLS

By default, METISSE only uses the essential columns and the additional columns specified in format_file for interpolation. However, when using METISSE in its standalone mode, there exists an option for interpolating in all the columns or certain extra columns of the input tracks. The interpolated quantities are printed in a MIST-style file file if write_eep_file = .true. in METISSE_controls.

Parameter	Description
read_all_columns	If `.true.`, interpolate in all columns of input files. Default is `.false.`
extra_columns	Extra columns to be used for interpolation. Up to 100 column names can be listed as strings, separated by commas. Only read if `read_all_columns` is `.false.`
extra_columns_file	Alternative way for listing extra column names. List one column name per line in the `extra_columns_file` and provide the path of the file here. Only read if `read_all_columns` is `.false.`.

! COLUMN CONTROLS
read_all_columns = .false.
extra_columns = ''
extra_columns_file = ''

2. METISSE input controls

METISSE_input_controls contains input parameters specific to METISSE.

For the most up-to-date variable names and their default values refer to metisse_defaults.

2.1. TRACK CONTROLS

Variable name	Description
METALLICITY_DIR	Absolute path to the folder containing the Metallicity File for the hydrogen stars. METISSE will stop if `METALLICITY_DIR` is an empty string.
METALLICITY_DIR_HE	Absolute path to the folder containing the Metallicity File for the naked helium stars. If `METALLICITY_DIR_HE` is an empty string, SSE fitting formulae for naked helium stars are used.
Z_accuracy_limit	METISSE checks for a match in metallicity based on the condition: $\frac{abs(Z\_files - Z\_input)}{min(Z\_files, Z\_input)} >$ `Z_accuracy_limit`, where $Z\_files$ is the metallicity value of the tracks (from the metallicity file) and $Z\_input$ is the input value. Default is 10^-2
mass_accuracy_limit	METISSE skips mass-interpolation and uses a neighboring mass track if the absolute difference between the initial mass of that track and the input mass is less than the `mass_accuracy_limit`. Default is 10^-4

! TRACK CONTROLS
METALLICITY_DIR = ''
METALLICITY_DIR_HE = ''
Z_accuracy_limit = 1d-2
mass_accuracy_limit = 1d-4

2.2. MISCELLANEOUS CONTROLS

Variable name	Description
verbose	If `.true.`, print important details when reading the input tracks on the terminal. Default is `.false.`.
write_eep_file	Generate a MIST-style file output file at every step of mass interpolation. Useful when computing evolution of isolated single stars with implicit mass loss and for debugging purposes. Default is `.false.`.
write_error_to_file	If `.true.`, error messages from METISSE are written to a file named `fort.99` otherwise they are printed on screen (does NOT apply to errors during reading input files). Default is `.true.`.
construct_postagb_track	Artificially construct the HRD (Hertzsprung-Russell diagram) track between tip of the AGB to the WD cooling track (for low-mass stars). It is important if input tracks do not contain this phase but can be used regardless. Default is `.false.`.

! MISCELLANEOUS CONTROLS

verbose = .false.
write_eep_file = .false.		
write_error_to_file = .true.
construct_postagb_track = .false.