NEWS The Swedish Research Council awards 12 MSEK to a project that will provide accurate experimental data about the highly excited energy levels of small molecules such as methane, ammonia and acetylene that are of importance in astrophysics. This data will help improve the accuracy of the theoretical models used to interpret the high-temperature spectra of hot-Jupiter exoplanets and other astronomical objects.
"It feels wonderful! Actually, I was not on the initial list of recipients and I was already mentally preparing for another round of writing proposals when a few days later I received a message from the Swedish Research Council that someone declined their grant and it is now given to me. I felt euphoric, because this grant is very prestigious and generous and it implies six years of funding that will allow us to concentrate on research," says Aleksandra Foltynowicz Matyba, associate professor at the Department of Physics at Umeå University.
An exoplanet is a planet that orbits a star other than the Sun. Many exoplanets are as large as Jupiter and orbit so close to their stars that their temperature reaches up to 700 degrees Celsius. Even though life as we know it cannot exist on those hot exoplanets, studying them gives us unique insights into our universe.
All information about these objects comes from satellite- and ground-based observations. The observed spectra carry information about the composition and conditions in the exoplanetary atmospheres, photochemistry and planetary formation. To extract it, we need accurate theoretical models of the high-temperature spectra verified by laboratory measurements. Such data is often missing even for the simplest molecules. Our understanding of the molecular structure is limited by the lack of high-precision experimental data about transitions to highly excited levels.
Within this project Aleksandra Foltynowicz-Matyba will measure and assign transitions to highly-excited energy levels of methane, ammonia and acetylene and provide experimental data that will help improve the accuracy of the theoretical models used to interpret the high-temperature spectra. To do this, she will use a technique called double-resonance spectroscopy. In this technique, a high power laser is used to increase the number of molecules in one particular excited energy level. Afterwards, a weaker probe laser is used to measure transitions from this level to higher energy levels.
To detect a large number of transitions Aleksandra will use an optical frequency comb as the probe laser. A frequency comb is a laser whose spectrum consists of hundreds of thousands of evenly spaced lines. This gives broad spectral coverage and high spectral resolution, a combination not available with any other light source.
"The molecular data that our project will provide is currently missing and cannot be obtained with any other technique. In a few years, the NASA’s James Webb Telescope and the European Ariel Space Mission will provide infrared spectra of exoplanetary atmospheres with resolution and sensitivity that much supersede what is currently available. I am excited that we got the chance to contribute to better understanding of these spectra and new scientific discoveries."
Foundation: Swedish Research Council Consolidator Grant
Grant: 12 million Swedish crowns for 2021-2026
Project title: Double-resonance spectroscopy of small molecules using an optical frequency comb
Project leader: Aleksandra Foltynowicz Matyba, Department of Physics, Umeå University.