Molecular line surveys are among the main tools to probe the structure and physical conditions in protoplanetary disks, the birthplace of planets. We used the flexibility of the PolyFiX correlator on the NOEMA interferometer to perform a deep survey from ?2.6 to 4mm (where fundamental transitions of most simple molecules occur) of the protoplanetary disk surrounding the well-known triple T-Tauri system GG-Tau A. Its large size, low temperature, and large mass make GG-Tau A disk an ideal laboratory to study cold molecular chemistry.
We present the observation results, including the first detection of CCS in a protoplanetary disk, and the analysis of the data with the radiative code DiskFit.