pint.derived_quantities.dth

pint.derived_quantities.dth(mp: Quantity, mc: Quantity, pb: Quantity) Quantity[source]

Post-Keplerian Roemer delay term

dth (\(\\delta_{\\theta}\)) is part of the relativistic deformation of the orbit

Parameters:
Returns:

dth

Return type:

astropy.units.Quantity

Raises:

Notes

Calculates

\[\begin{split}\\delta_{\\theta} = T_{\\odot}^{2/3} \\left(\\frac{P_b}{2\\pi}\\right)^{2/3} \\frac{3.5 m_p^2+6 m_p m_c +2m_c^2}{(m_p+m_c)^{4/3}}\end{split}\]

with \(T_\\odot = GM_\\odot c^{-3}\).

More details in Timing Models. Also see [13].