mergerfirstfuns¶
This is the documentation for the mergerfirstfuns module, which consists of the pre-matching parts of the procedure for simulating the merger/ringdown portions of gravitational waves from binary black holes, collected into modular functions.
quasi_normal_modes¶
quasi_normal_modes(eta)
Calculation of the final spin and quasi-normal mode factor used in the calculation of angular frequency for the merger/ringdown waveform, based on Buskirk et al. (2019) equations 19 and 20.
Parameters¶
- eta: float
Symmetric mass ratio of the binary, can be obtained from get_M_and_eta() in inspiralfuns.
Returns¶
- (sfin,wqnm): tuple of floats
The first constant is the final spin, the second is the quasi-normal mode factor used in subsequent calculations.
gIRS_coefficients¶
gIRS_coefficients(eta,sfin)
Calculation of several gIRS (generic implicit rotating source)-related coefficients used in the calculation of angular frequency for the merger/ ringdown waveform, based on Buskirk et al. (2019) Appendix C.
Parameters¶
- eta: float
Symmetric mass ratio of the binary, can be obtained from get_M_and_eta() in inspiralfuns.
- sfin: float
Final spin value, from quasi_normal_modes().
Returns¶
- (alpha,b,C,kappa): tuple of floats
Four gIRS-related constants used in subsequent calculations. (NOTE: alpha is not used by anything in mergerfirstfuns but is used in mergersecondfuns.)
merger_freq_calculation¶
merger_freq_calculation(wqnm,b,C,kappa)
Calculation of orbital angular frequency for the merger/ringdown portion, based on Buskirk et al. (2019) equations 17 and 18.
Parameters¶
- wqnm: float
Quasi-normal mode factor, from quasi_normal_modes().
- b: float
A gIRS coefficient, from gIRS_coefficients().
- C: float
A gIRS coefficient, from gIRS_coefficients().
- kappa: float
A gIRS coefficient, from gIRS_coefficients().
Returns¶
- [fhat,m_omega]: list of lists of floats
First list is the values over time of a sort of frequency parameter called fhat (f^), second list is the angular frequency.
fhat_differentiation¶
fhat_differentiation(fhat)
Calculation of derivative of fhat used by amplitude calculations in mergersecondfuns.
Parameters¶
- fhat: list of floats
Values of a sort of frequency parameter called fhat (f^) over time, from merger_freq_calculation().
Returns¶
- fhatdot: list of floats
Values of the time-derivative of fhat over time.
merger_time_conversion¶
merger_time_conversion(M)
Calculating times in real units corresponding to the times in geometric units used by other merger/ringdown functions.
Parameters¶
- M: float
Total mass of the binary, can be obtained from get_M_and_eta() in inspiralfuns.
Returns¶
- m_time: list of floats
The list of timesteps used by other merger/ringdown functions, but in seconds instead of geometric units.