Directly tracing the vertical stratification of molecules in protoplanetary disks

We aim to directly trace the vertical location of emitting surface multiple molecular tracers in protoplanetary disks. Our sample disks includes Elias 2-27, WaOph 6 and sources targeted by MAPS ALMA Large Program. The set molecules studied include CO isotopologues various transitions, HCN, CN, H2CO, HCO+, C2H c-C3H2. region is determined from channel maps, implementing accurate masking emission recover even at large radial distances star for low-SNR lines. layer obtained 4-10 lines each disk. IM Lup, HD163296 MWC 480 12CO 13CO show modulations, which are coincident with dust gaps kinematical perturbations. also present estimates gas pressure scale height sample. Compared physical-chemical models we find good agreement isotopologues. In HD 163296 CN HCN a similar intermediate layer, other disks, UV flux profiles lower than predicted theoretical models. H2CO highly structured profile, possibly indicative different formation pathways. It possible locations species that wide variety physical chemical disk properties. distribution found range heights $z/r = $ 0.5-0.05. Other mostly \leq $0.15. layering theory some systems, but not all, therefore dedicated chemical-physical needed further study understand surfaces.