posydon.binary_evol.SN
posydon.binary_evol.SN.profile_collapse
Collapse the profile of a star object into a BH.
This script is based on the physics explained in Appendix D of Bavera+2020.
- posydon.binary_evol.SN.profile_collapse.BZ_jet_power(M_dot, eta_phi, eta_a)[source]
Compute the Blandford-Znajek jet power.
This function computes the Blandford-Znajek jet power given the mass accretion, the efficiency factor for the magnetic flux, and the efficiency factor for the BH spin. This is based on the decomposition of the jet power in terms of the magnetic flux and the BH spin, see Gottlieb et al. (2023, 2024). We do not assume any disk state in this calculation, i.e. magnetically arrested disk (MAD), Neutrino dominated accretion flow (NDAF), or advection dominated accretion flow (ADAF). However, the functions for eta_phi and eta_a can be dependent on the disk type. Moreover, the efficiency factors are not constant and can change with the magnetic field and BH spin.
- posydon.binary_evol.SN.profile_collapse.compute_isco_properties(a, m_BH)[source]
Compute the BH innermost stable circular orbit (ISCO) parameters.
- posydon.binary_evol.SN.profile_collapse.do_core_collapse_BH(star, mass_collapsing, mass_central_BH=2.51, neutrino_mass_loss=None, max_neutrino_mass_loss=NEUTRINO_MASS_LOSS_UPPER_LIMIT, verbose=False)[source]
Do the core collapse of a star object with MESA profile provided.
- Parameters:
star (object) – Star object of a collapsing star containing the MESA profile.
mass_collapsing (float) – Remnant barionic mass in M_sun collapsing to form the BH. This is the mass left to collapse after applying a supernova prescriptions, see e.g. rapid and delayed mechanisms of Fryer et al. (2012).
mass_central_BH (float) – Mass of the central stellar layers (in M_sun) collasping directly to form a proto BH.
neutrino_mass_loss (float) – Mass (in M_sun) lost thorugh neutrinos in the formation of the central BH.
max_neutrino_mass_loss (float) – Maximum mass (in M_sun) lost thorugh neutrinos.
verbose (bool) – If True, it prints some informations.
- Returns:
core_collapse_results – A dictionary containing the following keys: ‘M_BH_total’ : float
The mass of the final BH in M_sun.
- ’a_BH_total’float
The dimensionless spin of the final BH.
- ’m_disk_accreted’float
The mass of the disk accreted by the BH in M_sun.
- ’m_disk_radiated’float
The mass of the disk radiated away in M_sun.
- ’BZ_jet_power_total’float
The total Blandford-Znajek jet power in erg/s.
# Additional keys that are not used in the current implementation: # ‘BZ_jet_power_array’ : np.array(BZ_jet_power_array), # Blandford-Znajek jet power at each shell collapse in erg/s # ‘M_BH_array’ : np.array(M_BH_array) # BH mass evolution in g # ‘a_BH_array’: np.array(a_BH_array) # Dimensionless spin evolution # ‘J_accreted_array’: np.array(J_accreted_array) # Angular momentum accreted from a given shell by the BH in CGS units. # ‘J_total_array’: np.array(J_total_array) # Total angular momentum in accreted shells + BH’s initial J # ‘J_disk_shell_array’: np.array(J_disk_shell_array) # Angular momentum accreted from the shell’s part collapsing to form a # disk in CGS units. # ‘radiation_eff_array’: np.array(radiation_eff_array) # Fraction of accretion disk radiated away, this is one minus accretion # efficiency. # ‘r_isco_array’: np.array(r_isco_array) # Radius of the innermost stable circular orbit in cm. # ‘j_isco_array’: np.array(j_isco_array) # Specific angular momentum at ISCO (prograde orbits) in CGS. # ‘M_direct_collapse_array’: np.array(M_direct_collapse_array) # Cumulative mass accreted through direct collapse in g. # ‘M_disk_array’: np.array(M_disk_array) # Cumulative mass accreted through the disk in g. # ‘dm_direct_array’: np.array(dm_direct_array) # Mass in shell with j < j_isco (direct collapse) in g # ‘dm_disk_array’: np.array(dm_disk_array) # Mass in shell with j > j_isco (forms a disk) in g # ‘j_shell_array’: np.array(j_shell_array) # Shell’s specific angular momentum in CGS # ‘M_total_array’: np.array(M_total_array) # Integrated mass (shells + initial BH) in g # ‘a_star_array’: np.array(a_star_array) # Star’s spin parameter # ‘max_he_mass_ejected’: max_he_mass_ejected # Max He mass that can be ejected during the disk formation
- Return type:
- posydon.binary_evol.SN.profile_collapse.get_ejecta_element_mass_at_collapse(star, compact_object_mass, verbose)[source]
Calculate the masses of H1, He4, and O16 in the ejecta. :param star: Star object of a collapsing star containing the MESA profile. :type star: object :param compact_object_mass: The mass of the compact object (in Msun), hence all above this mass will be ejected. :type compact_object_mass: float :param verbose: If True, it prints some informations. :type verbose: bool
- Returns:
h1_mass_ej (float) – Hydrogen mass in the ejecta. (in Msun)
he4_mass_ej (float) – Helium mass in the ejecta. (in Msun)
- posydon.binary_evol.SN.profile_collapse.get_initial_BH_properties(star, mass_collapsing, mass_central_BH, neutrino_mass_loss, max_neutrino_mass_loss, verbose)[source]
Collapse directly the center of the star and return useful quantities.
- Parameters:
star (object) – Star object of a collapsing star containing the MESA profile.
mass_collapsing (float) – Remnant barionic mass in M_sun collapsing to form the BH. This is the mass left to collapse after applying a supernova prescriptions, see e.g., rapid and delayed mechanisms of Fryer et al. (2012).
mass_central_BH (float) – Mass of the central stellar layers (in M_sun) collasping directly to form a proto BH.
neutrino_mass_loss (float) – Mass (in M_sun) lost through neutrinos in the formation of the central BH.
max_neutrino_mass_loss (float) – Maximum mass (in M_sun) lost thorugh neutrinos.
verbose (bool) – If True, it prints some informations.
- Returns:
mass_initial_BH (float) – Mass of the initial BH in units of g.
a_initial_BH (float) – Dimensionless spin of the initial BH.
J_initial_BH (float) – Angular momentum of the initial BH in g*cm^2/s.
angular_frequency_i (array floats) – Shell’s angular frequencies in s^-1 collapsing onto the initially-formed BH.
enclosed_mass_i (array floats) – Shell’s enclosed masses in g collapsing onto the initially formed BH.
radius_i (array floats) – Shell’s radii in cm collapsing onto the initially formed BH.
density_i (array floats) – Shell’s densities in g/cm^3 collapsing onto the initially formed BH.
dm_i (array floats) – Shell’s masses in g collapsing onto the initially formed BH.
dm_i (array floats) – Shell’s width in cm collapsing onto the initially formed BH.