title: Complex Organic Molecules in Protoplanetary Disks

authors: Catherine Walsh*, T. J. Millar, H. Nomura, E. Herbst, S. Widicus Weaver, Y. Aikawa, J. C. Laas, and A. I. Vasyunin

abstract: Protoplanetary disks are vital objects in star and planet formation: they act as the reservoir for the building blocks of planetary systems.  One open question is the origin of chemical complexity in the Solar System (and extrasolar systems) with hypotheses ranging from inheritance from the natal molecular cloud, to processing of simple molecules in ices in the protoplanetary disk, to 'in-situ' formation on and within plantesimal and planetary surfaces.   

In this presentation, I describe the results of an investigation into the synthesis of complex organic molecules (COMs) in a protoplanetary disk around a typical T Tauri star using a large gas-grain chemical network.  I compare the results with existing observational constraints including those molecules observed in nearby disks and cometary comae.  I also show some predictions for ALMA (the Atacama Large Millimetre/Submillimetre Array), which is expected to significantly increase the molecular inventory of protoplanetary disks.  I also discuss the influence of the disk accretion flow on the disk chemistry and postulate on the achievable chemical complexity in disks around stars which are both cooler and hotter than the Sun.