Denoting \(\tau =\) attack and \(\delta = \) slip time,* the source's time dependence is \begin{align}\label{eq:h} h(t) = \exp[{-(t+\delta)^2/\tau^2}] (t+\delta)/\tau, \qquad \Delta \equiv \delta/\tau \end{align}
*Pavlidou and Richardson 1997, Derveaux et al. 2003, Chadefaux et al. 2012