GWRemnantCalculator

class gw_remnant.gw_remnant_calculator.GWRemnantCalculator(time, h_dict, q, chi1=None, chi2=None, e_ref=None, E_initial=None, L_initial=None, M_initial=1, use_filter=False)[source]

Bases: GWPlotter, PeakLuminosityCalculator, AngularMomentumCalculator, TrajectoryCalculator, LinearMomentumCalculator, RemnantMassCalculator, InitialEnergyMomenta

Calculator for remnant properties of binary black hole mergers.

This class computes remnant properties and time evolution of physical quantities from gravitational waveform data. It combines functionality from multiple calculator classes to provide comprehensive analysis of binary black hole mergers.

Computed quantities include: - Energy flux and radiated energy - Linear momentum and kick velocity evolution - Angular momentum and spin evolution - Final remnant mass, spin, and kick velocity - Peak luminosity

All calculations are performed in geometric units where G=c=1, with masses in units of total mass M and time in units of M.

Parameters:

  • time (ndarray) – Array of time values in geometric units (M)

  • h_dict (dict[tuple[int, int], ndarray]) – Dictionary of complex waveform modes with (l,m) tuple keys, e.g., {(2,2): h_22(t), (3,3): h_33(t), …}

  • q (float) – Mass ratio q = m1/m2, where m1 >= m2

  • chi1 (ndarray | list[float] | None) – Spin vector [sx, sy, sz] for primary black hole at the start of the waveform, in dimensionless units. Default is None

  • chi2 (ndarray | list[float] | None) – Spin vector [sx, sy, sz] for secondary black hole at the start of the waveform, in dimensionless units. Default is None

  • e_ref (float | None) – Eccentricity at the reference time. User must provide accurate value; code does not validate. Default is None

  • E_initial (float | None) – Initial energy of the binary in units of total mass M. If None, computed using PN expressions. Set to 0 to inspect energy changes relative to reference. Set to known value (e.g., from NR simulation) for absolute tracking. Default is None

  • L_initial (float | None) – Initial angular momentum of the binary in units of M^2. If None, computed using PN expressions. Set to 0 to inspect angular momentum changes relative to reference. Set to known value (e.g., from NR simulation) for absolute tracking. Default is None

  • M_initial (float) – Initial total mass in units of M. Default is 1

  • use_filter (bool) – Whether to apply filtering to computed quantities. Default is False

h_dot

Time derivative of waveform modes

Type:

dict

E_dot

Energy flux as a function of time

Type:

np.ndarray

E_rad

Total radiated energy

Type:

float

Eoft

Cumulative radiated energy as a function of time

Type:

np.ndarray

Moft

Binary mass as a function of time

Type:

np.ndarray

remnant_mass

Final remnant black hole mass

Type:

float

P_dot

Time derivative of linear momentum vector [3 x N_times]

Type:

np.ndarray

Poft

Linear momentum vector as a function of time [3 x N_times]

Type:

np.ndarray

voft

Center of mass velocity vector as a function of time [3 x N_times]

Type:

np.ndarray

kickoft

Kick velocity magnitude as a function of time

Type:

np.ndarray

remnant_kick

Final kick velocity magnitude

Type:

float

remnant_kick_vector

Final kick velocity vector (3,) in units of c

Type:

np.ndarray

J_dot

Time derivative of angular momentum vector [3 x N_times]

Type:

np.ndarray

Joft

Angular momentum vector as a function of time [3 x N_times]

Type:

np.ndarray

spinoft

Dimensionless spin z-component as a function of time

Type:

np.ndarray

remnant_spin

Final remnant dimensionless spin z-component

Type:

float

spin_vector_oft

Dimensionless spin vector [3 x N_times] (x, y, z)

Type:

np.ndarray

remnant_spin_vector

Final remnant dimensionless spin vector (3,)

Type:

np.ndarray

L_peak

Peak luminosity

Type:

float

peak_kick

Peak kick velocity

Type:

float

xoft

Center-of-mass displacement vector [N_times x 3] in units of M

Type:

np.ndarray

remnant_displacement

Final center-of-mass displacement vector (3,)

Type:

np.ndarray

Inherits From:

GWPlotter: Plotting utilities for visualizing results PeakLuminosityCalculator: Peak luminosity calculations AngularMomentumCalculator: Angular momentum evolution TrajectoryCalculator: Center-of-mass trajectory LinearMomentumCalculator: Linear momentum and kick velocity RemnantMassCalculator: Mass and energy calculations InitialEnergyMomenta: Initial condition calculations

Example

>>> import numpy as np
>>> time = np.arange(-1000, 100, 0.1)
>>> h_dict = {(2,2): h_22_data, (3,3): h_33_data}
>>> calc = GWRemnantCalculator(time, h_dict, q=2.0,
...                           chi1=[0, 0, 0.5])
>>> calc.print_remnants()
>>> calc.plot_mass_energy()
get_remnant_properties()[source]

Return remnant properties as a dictionary.

Returns:

Dictionary containing:

  • ’mass_ratio’: Mass ratio q = m1/m2

  • ’M_initial’: Initial total mass

  • ’E_rad’: Total radiated energy

  • ’L_peak’: Peak luminosity

  • ’remnant_mass’: Final remnant mass

  • ’remnant_spin’: Final dimensionless spin (z-component)

  • ’remnant_spin_x’: Final dimensionless spin x-component

  • ’remnant_spin_y’: Final dimensionless spin y-component

  • ’remnant_spin_z’: Final dimensionless spin z-component

  • ’remnant_kick’: Final kick velocity in units of c

  • ’remnant_kick_kmps’: Final kick velocity in km/s

  • ’remnant_kick_x/y/z’: Final kick velocity vector components in units of c

  • ’peak_kick’: Peak kick velocity in units of c

  • ’remnant_displacement_x/y/z’: Final center-of-mass displacement

    components in units of M

Return type:

dict[str, float]

print_remnants()[source]

Print summary of remnant properties.

Displays key remnant quantities including mass ratio, initial mass, total radiated energy, peak luminosity, and final remnant mass, spin, and kick velocity. All quantities are printed in geometric units.

Return type:

None