Complex molecules : from molecular clouds to protoplanetary disks

Séminaire IPAG de Cécile Favre (IPAG), jeudi 12 novembre 2015 à 11h00, IPAG seminar room

One of the most important questions in the astrophysics of the interstellar medium (ISM) is whether, how, when, and where complex organic molecules (i.e. molecules that contain 6 or more atoms), including prebiotic species, are formed. And in the Interstellar-Earth connection context, could this have a bearing on the origin of life on Earth ? Formation mechanisms of complex organic species, which include potentially prebiotic molecules, are still much debated and may include grain-mantle chemistry and/or gas-phase chemistry. Understanding the mechanisms that lead to the interstellar molecular complexification, along with the involved physico–chemical processes, is mandatory to answer the above questions. The analysis of the emission of the interstellar molecules gives strong insight into the understanding of the physical conditions (temperature, density) and chemistry that are occurring in such environments. I will present some notable results on the detection of complex molecules, such as methyl formate and glycolaldehyde (pre-sugar), towards low- and high-mass star forming regions. They are based on (sub)millimeter single-dish (APEX, IRAM-30m, Herschel) and/or interferometric (PdBI, SMA, ALMA) observations of ISM sources. Then, in the second part of my talk, I will present our recent studies on the physico-chemistry of protoplanetary disks that are based on HD and C18O observations (SMA and HSO/PACS) and the chemical modeling of the DCO+ ion.