WUNA Lunch Talk:

Valentine Wakelam

Laboratoire d'Astrophysique de Bordeaux

Interstellar chemistry: from dense clouds to protoplanetary disks

September 19

12:10PM, Room 230, NRAO, Edgemont Road


The observation of molecules in the interstellar medium (ISM) gives information on the physic of the formation of stars and planets. For instance, each step of the formation of a planetary system is characterized by a chemical composition, which directly reflects the physical conditions of the medium and its evolutionary stage. Dense clouds show large abundances of unsaturated species formed in cold gas phase whereas in protostars, gas warm up favors grain surface reactions and the formation of large saturated molecules. With the improvement of observational instrument sensitivity and the opening of new wavelength ranges, more and more trace molecules are detected in the ISM. The future (sub) millimeter interferometer ALMA is promise of opening new windows on the ISM wealth. The more molecules are discovered, the more complex chemical models have to be to reproduce this peculiar chemistry.

In this presentation, I will present the chemical models that have been developed over the year to study the chemical composition of dense regions, their strengths and their weaknesses. I will also show how they can be used to better understand the chemical composition of protoplanetary disks and the link between the disk composition and the parent cloud.