Dr. Daniel Savin and Dr. Holger Kreckel at Columbia University will examine destruction rates for the hydrogen molecule H3+ in the laboratory with applications for studying molecular clouds and emission line objects such as Galactic and extragalactic gaseous nebulae. The laboratory measurements will focus on measurements of H3+ dissociative recombination, which plays an important role in the formation of complex molecules observed in molecular clouds. The team will also make similar measurements for oxygen (O2+), sulfur (S2+), and neon (Ne2+) molecules to determine the effective temperature of ionizing stars in HII regions.
This work will impact the astronomical community by generating atomic and molecular data that can be used to interpret astronomical observations. This will be a trans-disciplinary effort, bringing together astrophysics, atomic and molecular physics. The research will also help foster international collaborations in astrophysics as it will be carried out using the heavy-ion Test Storage Ring at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany, as no facilities currently exist in the U.S. for the proposed studies.
Molecules play an important role in the universe where they are a key component of primordial clouds, diffuse, translucent and dense molecular clouds, hot cores, photon dominated regions, protostellar disks, protoplanetary disks, planetary and satellite ionospheres, cometary comae, and circumstellar envelopes around dying stars. As we strive to improve our understanding of these objects, it is necessary to be able to model and interpret their chemical composition, charge balance, emission and/or absorption spectra, and thermal structure. This, in turn, requires reliable knowledge of the underlying molecular collisions which control these properties. We have carried out a series of experimental and modeling studies of various molecular reactions important for the cosmic objects listed above. Our experimental work includes studies of the chemistry leading to the formation of the first stars, electron driven chemistry, and molecular spectroscopy. Our modeling work includes studies of molecular-driven cooling in primordial clouds leading to the formation of the first stars and studies of the chemistry in dense molecular clouds. The broader impacts of our work have been many. We have trained three postdoctoral research scientists, one undergraduate, and a high school science teacher. The project has brought together researchers from many different institutions and countries. It has lead to several talks for the general public and inspired an art piece which was shown in New York City. Lastly, our first star results were widely reported in the media both in the U.S.A and around the world including in Brazil, Ethopia, France, Germany, India, Portugal, Russia, South Africa, Spain, Ukraine and Vietnam.
