mcfacts.physics.point_masses

Module for handling simple GR orbital evolution (Peters 1964)

Contain functions for orbital evolution and converting between

units of r_g and SI units

This module is its own module because it does not import other parts

of mcfacts, in order to avoid circular imports

mcfacts.physics.point_masses.orbital_separation_evolve(mass_1, mass_2, sep_initial, evolve_time)

Calculates the final separation of an evolved orbit

Parameters:
Returns:

sep_final – Final separation [m] of two bodies

Return type:

astropy.units.quantity.Quantity

mcfacts.physics.point_masses.orbital_separation_evolve_reverse(mass_1, mass_2, sep_final, evolve_time)

Calculates the initial separation of an evolved orbit

Parameters:
Returns:

sep_initial – Initial separation [m] of two bodies

Return type:

astropy.units.quantity.Quantity

mcfacts.physics.point_masses.r_g_from_units(smbh_mass, distance)

Calculate the SI distance from r_g

Parameters:
Returns:

distance_rg – Distances [r_g]

Return type:

numpy.ndarray

mcfacts.physics.point_masses.r_schwarzschild_of_m(mass)

Calculate the Schwarzschild radius from the mass of the object.

Parameters:

mass (numpy.ndarray or float) – Mass [Msun] of the object(s)

Returns:

r_sch – Schwarzschild radius [m] with astropy.units.quantity.Quantity

Return type:

numpy.ndarray

mcfacts.physics.point_masses.si_from_r_g(smbh_mass, distance_rg, r_g_defined=None)

Calculate the SI distance from r_g

Parameters:
  • smbh_mass (float) – Mass [M_sun] of the SMBH

  • distance_rg (array_like) – Distances [r_{g,SMBH}]

Returns:

distance – Distance in SI with astropy.units.quantity.Quantity type

Return type:

numpy.ndarray

mcfacts.physics.point_masses.time_of_orbital_shrinkage(mass_1, mass_2, sep_initial, sep_final)

Calculates the GW time for orbital shrinkage

Calculate the time it takes for two orbiting masses to shrink from an initial separation to a final separation (Peters)

Parameters:
Returns:

time_of_shrinkage – Time [s] of orbital shrinkage

Return type:

astropy.units.quantity.Quantity