Relating the Chemistry of Distant Galaxies to the Milky Way

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

Some of the most exciting research in astronomy focuses on the birth of galaxies over cosmic time. To do this well we must understand how stars form in other galaxies. Stars and their planets assemble out of the densest gas in molecular clouds. Such gas clouds in space typically contain enough material to form more than 10,000 stars like the Sun. Astronomers use radio telescopes to discover the types of molecules in clouds forming stars. The molecules have unique signatures, which are matched to laboratory measurements, enabling studies of chemistry at great distances from the Earth. The radio signatures are patterns of high intensity signals at specific radio frequencies. Astronomers use these identifications to deduce the chemistry, temperature and density of the regions forming stars. Fortunately, specific molecules in molecular clouds are likely tied to specific conditions prevailing in the gas. To give an example, the carbon monoxide (CO) molecule is found to reside in gas at any density. In contrast to this, hydrogen cyanide (HCN) molecule is rather tied to gas at the high densities. Because nearby molecular clouds are brighter, observations of our Milky Way are easier than observations of more distant galaxies. The investigator studies molecular clouds in the Milky Way, where the chemistry is thought to be better understood. The investigator will confirm the accuracy which molecular line observations can be used to measure important parameters relating to star formation and interstellar chemistry. The investigator will combine new observations with models for the physical conditions in these molecular clouds. The investigator will determine how sensitively their observations are tied to the physical conditions in the molecular clouds. The investigator will share their research experience with students in community colleges. The investigator enables easy student access to their data using a computing tool, called "Jupyter Notebooks", which work in common web browsers. This approach teaches computer skills, while not requiring excessive special purpose software to be installed on the students? computers. The data and analysis tools will be developed into classroom material for undergraduate courses. This is done in collaboration with community colleges in Massachusetts. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.