Brian Jackson edited We_can_use_the_encounter__.tex  over 8 years ago

Commit id: 15c558d4a4502deaf5a4d406a2d4692ae91cd232

deletions | additions      

       

We can use the encounter geometry to model the statistical probability for $P_{\rm obs}$ and $\Gamma_{\rm obs}$ to fall within a certain range of values, given a distribution of $P_{\rm act}$- and $\Gamma_{\rm act}$-values. The probability density for passing between $b$ and $b + db$ of a devil is $dp(b) = 2 b\ db / b_{\rm max}^2 $ for $b \le b_{\rm max}$. In this context, we can take $b_{\rm max} = \left( \dfrac{\Gamma_{\rm act}}{2} \right) \sqrt{\dfrac{P_{\rm act} - P_{\rm min}}{P_{\rm min}}}$ min}}}.$  Holding $\Gamma_{\rm act}$ fixed, we can use the above probability density expression and Equation \ref{eqn:Gamma_obs} to calculate the probability density for an encounter to give an observed profile width between $\Gamma_{\rm obs}$ and $\Gamma_{\rm obs} + d\Gamma_{\rm obs}$: \begin{equation}  \label{eqn:dp_dGamma_obs}  \dfrac{dp}{d\Gamma_{\rm obs}} = \dfrac{\Gamma_{\rm obs}}{b_{\rm max}^2} = 4 \Gamma_{\rm act}^{-2} \left( \dfrac{P_{\rm min}}{P_{\rm act} - P_{\rm min}}\right) \Gamma_{\rm obs}.