Toward a robust physical and chemical characterization of heterogeneous lines of sight: The case of the Horsehead nebula

Léontine Ségal, Antoine Roueff, Jérôme Pety +28

Dense cold molecular cores/filaments are surrounded by an envelope of translucent gas. Some of the low-J emission lines of CO and HCO${}^{+}$ isotopologues are more sensitive to the co…