We run numerical simulations of molecular clouds ( MCs ) , adopting properties similar to those found in the Central Molecular Zone ( CMZ ) of the Milky Way .
For this , we employ the moving mesh code A repo and perform simulations which account for a simplified treatment of time-dependent chemistry and the non-isothermal nature of gas and dust .
We perform simulations using an initial density of n _ { 0 } = 10 ^ { 3 } cm ^ { -3 } and a mass of 1.3 \times 10 ^ { 5 } M _ { \odot } .
Furthermore , we vary the virial parameter , defined as the ratio of kinetic and potential energy , \alpha = E _ { \text { kin } } / |E _ { \text { pot } } | , by adjusting the velocity dispersion .
We set it to \alpha = 0.5 , 2.0 and 8.0 , in order to analyze the impact of the kinetic energy on our results .
We account for the extreme conditions in the CMZ and increase both the interstellar radiation field ( ISRF ) and the cosmic-ray flux ( CRF ) by a factor of 1000 compared to the values found in the solar neighbourhood .
We use the radiative transfer code R admc -3 d to compute synthetic images in various diagnostic lines .
These are [ C ii ] at 158 \mu m , [ O i ] ( 145 \mu m ) , [ O i ] ( 63 \mu m ) , ^ { 12 } CO ( J = 1 \rightarrow 0 ) and ^ { 13 } CO ( J = 1 \rightarrow 0 ) at 2600 \mu m and 2720 \mu m , respectively .
When \alpha is large , the turbulence disperses much of the gas in the cloud , reducing its mean density and allowing the ISRF to penetrate more deeply into the cloud ’ s interior .
This significantly alters the chemical composition of the cloud , leading to the dissociation of a significant amount of the molecular gas .
On the other hand , when \alpha is small , the cloud remains compact , allowing more of the molecular gas to survive .
We show that in each case the atomic tracers accurately reflect most of the physical properties of both the H _ { 2 } and the total gas of the cloud and that they provide a useful alternative to molecular lines when studying the ISM in the CMZ .