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.compute_isco_properties(a, m_BH)[source]

Compute the BH innermost stable circular orbit (ISCO) parameters.

Parameters

  • a (float) – Dimnesionless BH spin.

  • m_BH (float) – Mass of the BH in g.

Returns

  • r_isco (float) – Radius of the ISCO in CGS units (cm).

  • j_isco (float) – Specific angular momentum at ISCO in CGS units (cm^2/s).

  • efficiency (float) – Orbital energy efficiency at ISCO.

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=0.5, 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

  • M_BH_total (float) – Mass of the final BH in M_sun.

  • a_BH_total (float) – Dimensionless spin of the final BH.

  • M_BH_array (array floats) – BH mass evelution in g.

  • a_BH_array (array floats) – Dimensionless spin evolution.

  • J_accreted_array (array floats) – Angular momentum accreted from a given shell by the BH in CGS units.

  • J_total_array (array floats) – Total angular momentum in accreted shells plus BH’s initial angular momentum in CGS units.

  • J_disk_shell_array (array floats) – Angular momentum accreted from the shell’s part collapsing to form a disk in CGS units.

  • radiation_eff_array (array floats) – Fraction of accretion disk radiated away, this is one minus accretion efficiency.

  • r_isco_array (array floats) – Radius of the innermost stable circular orbit in cm.

  • j_isco_array (array floats) – Specific angular momentum at the innermost stable circular orbit in CGS.

  • M_direct_collapse_array (array floats) – Cumulative mass accreted through direct collapse in g.

  • M_disk_array (array floats) – Cumulative mass accreted thorugh the disk in g.

  • dm_direct_array (array floats) – Shell’s mass accreted through direct collapse in g.

  • dm_disk_array (array floats) – Shell’s mass accreted thorugh the disk in g.

  • j_shell_array (array floats) – Shell’s specific angular momentum in CGS.

  • M_total_array (array floats) – Cumulative mass of shells and initial BH in g.

  • a_star_array (array floats) – Dimensionless spin parameter of the star.

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.