Power of PolyFiX at NOEMA to study disk chemistry: sulfur species in DM Tau

Dima Semenov

Tuesday December 1st, 14:45

We performed a deep search for CCS, SO2, OCS, H2S, H2CS and other molecules in the DM Tau protoplanetary disk at 2mm with PolyFiX@NOEMA. With a beam of ~2''x1'' and a spectral resolution of 0.3 km/s, a high sensitivity of ~3.8 mJy/beam was achieved. We detected o-H2S, o-H2CS, and DNC (first time in DM Tau) as well as H13CO+, N2D+, and, tentatively, HC3N. We have not detected SO2, our main target molecule, as well as OCS. We used the non-LTE radiative transfer code pyRADEX to derive disk-averaged column densities and their upper limits. These values, together with our previous ALMA CS data were used for disk chemical modeling. The best-fit model that fits reasonably well the CS, H2S and H2CS column densities and the upper limits of SO, OCS and SO2 in the DM Tau disk assumes a non-solar gas-phase C/O ratio of ~1 and a stellar X-ray luminosity of 10^31 erg/s, supporting previous findings.