determine_stationarity

legwork.evol.determine_stationarity(f_orb_i, t_evol, ecc_i, m_1=None, m_2=None, m_c=None, stat_tol=0.01)[source]

Determine whether a binary is stationary

Check how much a binary’s orbital frequency changes over t_evol time. This function provides a conservative estimate in that some binaries that are stationary may be marked as evolving. This is because the eccentricity also evolves but only use the initial value. Solving this in full would require the same amount of time as assuming the binary is evolving.

Parameters
forb_ifloat/array

Initial orbital frequency

t_evolfloat

Time over which the frequency evolves

eccfloat/array

Initial eccentricity

m_1float/array

Primary mass (required if m_c is None)

m_2float/array

Secondary mass (required if m_c is None)

m_cfloat/array

Chirp mass (overrides m_1 and m_2)

stat_tolfloat

Fractional change in frequency above which we do not consider a binary to be stationary

Returns
stationarybool/array

Mask of whether each binary is stationary