Jinjun Liu
University of Louisville, KY·Chemistry
Aging carbon-rich stars shed shells of gas that host exotic molecules, among them metal-bearing free radicals, reactive species carrying unpaired electrons. Finding such molecules with telescopes requires knowing their exact spectral fingerprints in advance, and those fingerprints have to be measured in a laboratory first.
- Fields
Chemistry
Physics
Astronomy & Astrophysics
- Topics
high-resolution laser spectroscopy
free radicals
magnesium-bearing molecules
- Grants
- 1 known grant, through Aug 2028
What they work on
- Develop methods to produce magnesium-bearing carbon chains and clusters with odd numbers of carbon atoms, using laser ablation of magnesium with organic precursors and cooling in a supersonic molecular beam.
- Record vibrationally resolved spectral surveys with nanosecond pulsed lasers and then rotationally resolved optical and infrared spectra with continuous-wave lasers, yielding fingerprints precise enough for astronomical searches.
- Apply quantum chemical calculations and purpose-built Hamiltonian models to characterize pseudo-Jahn-Teller and spin-orbit interactions, non-Born-Oppenheimer effects that govern the molecules' energy levels and internal dynamics.
More about the research
This project targets magnesium-bearing carbon chains and clusters. Those with an odd number of carbon atoms are predicted to exist in the circumstellar envelopes of evolved carbon stars but have never been detected.
Why it matters
Reference spectra from the laboratory are what allow astronomers to recognize a molecule in telescope data, so this work could enable the first detections of predicted magnesium-bearing carbon radicals around evolved carbon stars. The same molecules are central to optical cycling, in which lasers repeatedly excite and cool a molecule, so characterizing them may also support precision spectroscopy, low-temperature chemistry, tests of fundamental physics and quantum information science.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
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David Nesbitt
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Measure how fast molecules such as HCl, DCl, CO, CO2, OCS and NO scatter from liquids including water, salty water, glycerin and oils, using supersonic molecular beams and high-resolution laser spectroscopy.
The school
University of Louisville: 15 labs on PI Pages, $225M a year on research, 159 research doctorates a year.
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