bilby_to_lalsimulation_spins¶
- bilby_to_lalsimulation_spins(theta_jn, phi_jl, tilt_1, tilt_2, phi_12, a_1, a_2, mass_1, mass_2, reference_frequency, phase)[source]¶
Convert Bilby spin parameters to the Cartesian representation used by lalsimulation.
The definitions follow Table E1 of Romero-Shaw et al. (2020), https://arxiv.org/abs/2006.00714, and the corresponding lalsimulation transformation.
- Parameters:
- theta_jnfloat
Zenith angle between the total angular momentum and the line of sight, in radians.
- phi_jlfloat
Azimuthal angle of the Newtonian orbital angular momentum on its cone about the total angular momentum, in radians.
- tilt_1float
Zenith angle between the primary spin and the Newtonian orbital angular momentum, in radians.
- tilt_2float
Zenith angle between the secondary spin and the Newtonian orbital angular momentum, in radians.
- phi_12float
Difference between the azimuthal angles of the two spin vectors, in radians.
- a_1float
Primary dimensionless spin magnitude, between 0 and 1.
- a_2float
Secondary dimensionless spin magnitude, between 0 and 1.
- mass_1float
Detector-frame primary mass, in kilograms.
- mass_2float
Detector-frame secondary mass, in kilograms.
- reference_frequencyfloat
Non-zero reference gravitational-wave frequency, in Hz.
- phasefloat
Orbital phase at
reference_frequency, in radians.
- Returns:
- iotafloat
Zenith angle between the Newtonian orbital angular momentum and the line of sight, in radians.
- spin_1x, spin_1y, spin_1z, spin_2x, spin_2y, spin_2zfloat
Dimensionless Cartesian spin components in the frame used by lalsimulation waveform generators.