3 May 2012
3 May 2012
Speaker: Karin Oberg (CfA)
Title: pH Lecture: The astrochemical origins of prebiotic molecules
Abstract:Simple sugars, amino acids and other prebiotic molecules have been detected in comets and meteorites. This suggests that delivery of volatiles to Earth was accompanied by a complex organic soup. Through chemical imaging of disks around nearby young stars, with the Submillimeter Array and ALMA, we can directly constrain where some of the smaller organics, such as H2CO and HCN, form in analogs to the Solar Nebula. Currently disk observations cannot, however, be used to investigate under which astrophysical conditions these simple molecules evolve into more complex ones. To address this question, we have instead combined gas and ice observations toward embedded protostars with laboratory experiments that simulate the chemistry in icy mantles of interstellar grains. The results show that the CH3OH ice content and the ice temperature are key regulators of formation of prebiotic molecules. When combining this information with our disk imaging results we can begin to predict when and where larger prebiotic molecules form during planet formation in disks. Some of these predictions will soon be tested by ALMA and I will end this lecture with a discussion of some of the exciting disk chemistry results that we can expect in the age of ALMA, and a preview of the next generation of ice experiments that are being constructed to interpret these astrochemical data.