The cloud crushing time is given by: $t_{cc}=\frac{\chi^{1/2}a_0}{v_b}.$ So, for a cloud of radius $a_0=0.1~\text{kpc}$, the cloud crushing times are:
| $\chi$ | Physical Scenario | $v_b=10~\text{km}\text{s}^{-1}$ | $v_b=100~\text{km}\text{s}^{-1}$ | $v_b=1000~\text{km}\text{s}^{-1}$ |
|---|---|---|---|---|
| $10^2$ | Cold atomic cloud embedded in warm neutral or ionized medium, Warm gas embedded in coronal gas | $9.8\times10^{6}~\text{yr}$ | $9.8\times10^{5}~\text{yr}$ | $9.8\times10^{4}~\text{yr}$ |
| $10^3$ | Molecular gas in warm gas | $3.1\times10^{7}~\text{yr}$ | $3.1\times10^{6}~\text{yr}$ | $3.1\times10^{5}~\text{yr}$ |
| $10^4$ | Cold atomic gas in coronal gas | $9.8\times10^{7}~\text{yr}$ | $9.8\times10^{6}~\text{yr}$ | $9.8\times10^{5}~\text{yr}$ |
In general, cold molecular gas exists at around $\sim10~\text{K}$, cold atomic gas is $\sim10^2~\text{K}$, warm neutral or photoionized warm ionized gas is $\sim10^4~\text{K}$, and hot coronal gas is $\sim10^6~\text{K}$. The information for these phases and the cloud crushing scales are taken from Klein et al. (1994).