The Astrochemical Impact of Cosmic Rays in Protoclusters II: CI-to-H${}_2$ and CO-to-H${}_2$ Conversion Factors

We utilize a modified astrochemistry code which includes cosmic ray attenuation in-situ to quantify the impact of different cosmic-ray models on the CO-to-H${}_2$ and CI-to-H${}_2$ conversion factors, $X_{\mathrm{C}\mathrm{O}}$ and $X_{\rm CI}$, respectively. We consider the impact of cosmic rays accelerated by accretion shocks, and show that clouds with star formation efficiencies greater than 2% have $X_{\mathrm{C}\mathrm{O}}=(2.5\pm 1)\times {10}^{20}$ cm${}^{-2}$(K km s${}^{-1}$)${}^{-1}$, consistent with Milky Way observations. We find that changing the cosmic ray ionization rate from external sources from the canonical $\zeta \approx 10^{-17}$to$\zeta \approx 10^{-16}$s$^{-1}$, which better represents observations in diffuse gas, reduces $X_{\mathrm{C}\mathrm{O}}$ by 0.2 dex for clusters with surface densities below 3 g cm${}^{-2}$. We show that embedded sources regulate $X_{\mathrm{C}\mathrm{O}}$ and decrease its variance across a wide range of surface densities and star formation efficiencies. Our models reproduce the trends of a decreased $X_{\mathrm{C}\mathrm{O}}$ in extreme cosmic ray environments. $X_{\mathrm{C}\mathrm{I}}$ has been proposed as an alternative to $X_{\mathrm{C}\mathrm{O}}$ due to its brightness at high redshifts. The inclusion of internal cosmic ray sources leads to 1.2 dex dispersion in $X_{\rm CI}$rangingfrom$2\times10^{20} < X_{\rm CI} < 4\times10^{21}$cm$^{-2}$ (K km s${}^{-1}$)${}^{-1}$. We show that $X_{\mathrm{C}\mathrm{I}}$ is highly sensitive to the underlying cosmic ray model.