The prime objective of this project directed by Dr. Karen Magee-Sauer is to measure and compare abundances of ammonia (NH3), hydrogen cyanide (HCN), and acetylene (C2H2) in several comets. Other nitriles (HNC, HC3N) and hydrocarbons (C4H2) will be targeted when a relatively bright comet is available. The nitrogen chemistry of comets is not very well characterized. This is largely due to the difficulty in measuring emission from N2. Thus, it is very important to gain an understanding of the products of N2 processing to characterize the nitrogen abundance in comets. Comparing the abundances of nitriles in comets with their corresponding abundances in interstellar clouds will provide clues to nitrogen processing during comet formation. Determining relative abundances of interrelated symmetric hydrocarbon species (CH4, C2H2, C2H6) is important for constraining cometary formation scenarios. Common relative hydrocarbon abundances for a group of comets might reflect common processing histories.
The focus of this project is to utilize the expanding field of ground-based infrared spectroscopy to determine cometary composition through quantitative measurements of several key volatile species. The high spectral and spatial resolution afforded by long-slit infrared spectroscopy enables the detection of multiple emission features of each species, and yields information on their production. When the signal-to-noise is sufficiently high, the spatial profiles can separately identify material released from the nucleus from that produced in the coma. This will help answer the basic question of the composition of native ices in comets, and help constrain models of the solar system. Because comets are intrusive visitors to the planets within our solar system, they introduce new molecules into these environments. What role the delivery of organics and water by comets played in the emergence and evolution of life on Earth is a key question in the field of astrobiology. The composition of comets is also an important link to the study of the evolution of planetary atmospheres.
Broader Impacts: The broader objectives of this project are to strengthen the research environment and to promote the integration of research and education at Rowan University, an undergraduate institution. To work toward these objectives, this work will involve undergraduate students in all aspects of the research. The goal will be to develop students trained in computational, analytical, and communication skills required for future success in science, engineering, and education fields. The interdisciplinary nature of astronomical research makes it open to students from varying backgrounds. Participation in astronomical research provides transferable computer and analytical skills to other scientific fields. As a result, past research students are currently employed and/or studying in engineering, chemistry, and marine biology fields. Students from under-represented groups correspond to over 50% of past student participation in this research. This project offers undergraduates the opportunity to do research that they would otherwise not have the opportunity to do. This research program has enabled students to attend national undergraduate conferences, participate in summer research programs, and travel to major observatories. Continuing to provide these types of external experiences, along with learning everyday in a research-rich environment play a central role in the development of future scientists. ***
