Parameter definitions and units

The parameters used to describe a CBC within GWFish are as follows:

• 'mass_1': the mass of the primary object in the source frame, in solar masses \(M_{\odot}\);

• 'mass_2': the mass of the secondary object in the source frame, in solar masses \(M_{\odot}\);

• 'redshift': the redshift of the merger;

• 'luminosity_distance': the luminosity distance of the merger, in Megaparsecs;

• 'theta_jn': the angle between the observation direction \(\vec{N}\) and the total angular momentum of the merger - the sum of orbital angular momentum and the compact objects’ spins, \(\vec{J} = \vec{L} + \vec{S}_1 +\vec{S}_2 + (\text{GR corrections})\), as opposed to \(\iota\), which is the inclination angle between the observation direction and the orbital angular momentum \(\vec{L}\) -, in radians;

• 'psi': the polarization angle of the merger, in radians;

• 'phase': the initial phase of the waveform, in radians;

• 'ra': the right ascension of the merger, in radians;

• 'dec': the declination of the merger, in radians;

• 'geocent_time': the time of merger, expressed as GPS time;

• 'max_frequency_cutoff': a maximum frequency at which to cut off the waveform, in Hz;

• 'a_1': component of spin of the primary object along the orbital angular momentum, in units of the square of the mass (often denoted as \(\chi = J / M^2\) in \(c=G=1\) natural units), dimensionless (and \(\in [-1, 1]\)), not available for all approximants;

• 'a_2': component of the spin of the secondary object along the orbital angular momentum, not available for all approximants.

• 'lambda_1': tidal polarizability \(\Lambda_1\) of the primary (compact) star; for details on the definition see e.g. section III.D of the GW170817 properties paper. This parameter is not available for all approximants;

• 'lambda_2': tidal polarizability \(\Lambda_2\) of the secondary (compact) star, not available for all approximants.

Warning

Including parameters which do not apply for a specific approximants (e.g. giving 'a_1' for 'gwfish_TaylorF2') will not currently raise an error, the parameters will be simply ignored.