Complex organic molecules are detected in various astrophysical environments. They are particularly abundant in the warm inner regions of protostars, where planets, comets and asteroids are expected to form. These molecules may survive during the star formation process and be incorporated into asteroids and comets, which could deliver them to planetary embryos through impacts. This molecular delivery could favor the emergence of life. It is, therefore, important to understand how these molecules form and how they evolve towards more complexity.

Thanks to the high spatial resolution and high sensitivity of the interferometers ALMA and NOEMA, new opportunities were offered to astronomers to characterize the molecular complexity in low-mass star-forming regions. In particular, several new detections of complex molecules were obtained in the framework of the PILS program, an unbiased spectral survey of the solar-type protostar IRAS 16293-2422 with ALMA (e.g., Jorgensen et al. 2016, Lykke et al. 2017, Ligterink et al. 2017). Isotopologues of several complex molecules (D, 15N, 13C) were also detected for the first time in the interstellar medium (e.g., Coutens et al. 2016, Jorgensen et al. 2016), which can help constrain formation pathways of molecules. In this talk, I will present some of the recent results obtained with the ALMA/PILS survey. I will especially mention the recent detection of cyanamide (NH2CN), one of the rare interstellar molecules with 2 Nitrogen atoms, as well as its deuterated form (Coutens et al. 2018) and I will discuss what these observations teach us regarding its formation.

References :
Coutens et al. 2016, A&A, 590, L6
Coutens et al. 2018, A&A in press (arXiv 1712.09548)
Jørgensen et al. 2016, A&A, 595, A117
Ligterink et al. 2017, MNRAS 469, 2219
Lykke et al. 2017, A&A 597, A53