*************** 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.