(i) the energy difference of 10.77cm$^{-1}$ ($E/k\approx 15.5$K) between the lowest *para* and *ortho* rotational levels, and (ii) the spin statistical weights, this ratio corresponds to an equilibrium temperature of $9\pm 1$K. Due to the different beam sizes used to observe the $N_{Ka,\,Kc} = 1_{1,1} \leftarrow 0_{0,0}$, and $2_{1,2} \leftarrow 1_{0,1}$ transitions, the $p$- is preferentially sampled in the inner warmer region; therefore, this value is likely to be slightly overestimated.

For the same reason, the evaluation of the abundance ratios between amidogen isotopologues requires some careful considerations. From the averaged $N$ values we obtained $[\ce{NHD}]/[\ce{NH2}] = 0.87\pm 0.14$, hinting to a very high deuteration level for amidogen, lying in the 70-100% range. We consider this results as robust. The HPBW of the observations differs by only 25%, thus the source area sampled by the antenna is similar for both and lines. Furthermore, the energy difference between *ortho* and *para* species of is 21.11cm$^{-1}$ ($E/k_{\ensuremath{\mathrm{B}}}\approx 30.4$K), and the contribution of the unobserved $p$- is expected to be less than 5% at 10K. Finally, since the used transitions have their lower level located at “zero” energy, the product of two exponential terms in Eq.  tends to 1 for small $h\nu_0/k_{\ensuremath{\mathrm{B}}}T_{\ensuremath{\mathrm{ex}}}$, and 