Tracing the geometry of the inner protoplanetary disc
In protoplanetary discs dynamical effects due to planet formation are expected to lead to a gradual removal of material close to the orbit of the planet. This can lead to the presence of gaps or holes in the disc.
The ro-vibrational line transitions of the CO molecule are frequently observed from the warm inner parts of protoplanetary discs, the same regions where we expect these gaps or holes caused by planet formation to be present.
Using observed spectra collected with CRIRES/VLT, and detailed models calculated with the thermo-chemical disc code ProDiMo, I have studied how CO ro-vibrational line profiles from high resolution near-IR spectra can reveal the location of gaps/holes in protoplanetary discs.
Studying the line fluxes, widths and shapes of these line profiles, dust gaps, dust+gas gaps, or unusually extended emitting regions can be identified. Hence, inner disc geometries that appear degenerate from dust observations alone, can be characterized in much greater detail by the analysis of CO ro-vibrational line profiles.