Ryan Boyden edited section_Methods_label_methods_subsection__.tex  over 8 years ago

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As in \citet{Offner_2015}, we post-process each output with the radiative transfer code {\sc radmc-3d}\footnote{http://www.ita.uni-heidelberg.de/~dullemond/software/radmc-3d/} in order to compute the $^{12}$CO (1-0) emission. We solve the equations of radiative statistical equilibrium using the Large Velocity Gradient (LVG) approach \citep{shetty11}. We perform the radiative transfer using the densities, temperatures, and velocities of the simulations flattened to a uniform $256^3$ grid. We convert to CO number density by defining $n_{\rm H_2} = \rho/(2.8 m_p)$ and adopting a CO abundance of [$^{12}$CO/H$_2$] =$10^{-4}$ \citep{frerking82}. Gas above 800 K or with $n_{\rm H_2} < 10$ cm$^{-3}$ is set to a CO abundance of zero. This effectively means that gas inside the wind bubbles is CO-dark. The CO abundance in regions with densities $n_{\rm H_2} > 2 \times 10^4$ cm$^{-3}$ is also set to zero, since CO freezes-out onto dust grains at higher densities \citep{Tafalla_2004}. In the radiative transfer calculation, we include sub-grid turbulent line broadening by setting a constant micro-turbulence of 0.25$\kms$. The data cubes have a velocity range of $\pm 10\kms$ and a spectral resolution of $\Delta v = 0.156~ \kms$.  [Ryan - explain the next steps in 2-3 sentences]  We convert our runs into synthetic observations of the nearby Perserus molecular cloud by setting them at a distance of 250 pc and redefining their domain’s dimensions as angular position. The emission’s (?) units are scaled to temperature (K) using the Rayeigh-Jeans approximation. [add a sentence on how we’ve create PPV cubes of emission…either here or in start of 2.3]  \subsection{Statistical Analysis}