Sarah Nickerson (she/her)
Research Scientist
I am currently studying the molecular chemistry around a massive protostar in the Orion Nebula.
Current research
Questions
I am studying molecules at a crucial stage in their journey through the interstellar medium. Around the hot cores of massive protostars we can observe the molecules as they heat up and are liberated from icy mantels. This stage links the cold molecular clouds that birth stars to planetary systems such as our own.
The molecules in hot cores bear information on the physical conditions and chemistry in massive star forming regions. By studying them, we can also find the origins of these molecules themselves. We are studying high resolution spectra with SOFIA/EXES and the molecules we find here will provide a library by which to compare lower resolution James Webb Space Telescope observations and identify molecules in protoplanetary systems.
Approach
When a light source, such as a protostar, shines through gas, the molecules in that gas absorb the light at characteristic frequencies. Similarly, excited molecules release light at other characteristic frequencies. These molecular signatures show up as spectra that we can use to study the molecular content of the gas in space.
Innovations & Discoveries
By analyzing hot core spectra in the mid-infrared, I have found molecules that are inaccessible to other wavelengths. Ratios of these molecules can then date the evolutionary stage of the hot core because they are destroyed and created at different rates as the protostar heats up.
Technical Description
Sub-mm/mm, radio, and far infrared observations can probe molecules in the cooler outer envelopes of hot cores, but in order to study the molecular chemistry closest to the center of hot cores, one needs to observe in the mid infrared (MIR). Many molecules and transition types are accessible exclusively in the MIR. Despite the regime’s importance, there is a paucity of high-resolution spectral observations in the MIR compared to longer wavelengths. This is due to heavy atmospheric interference from the ground, and relatively lower spectral resolution from space-based missions. Only SOFIA/EXES can access the entire MIR with high enough spectral resolution to study individual molecular transitions and identify them with clarity. I am currently studying the MIR spectra of hot cores in order to gain unique access to these molecules.
About Sarah
Where are you from, and what were you doing before BAERI?
I grew up in Toronto and now live in the Bay Area. Before coming to BAERI I was working on my PhD at the University of Zürich where I modeled molecular hydrogen in galaxy-scale simulations.
What’s one job-related thing that you love talking about with other people?
All of it. I love astrophysics and could talk to anyone about anything in the field.
How about a non-job related thing?
I love hiking and immersing myself in nature on the weekends.
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explorers, writers, and more. Our shared belief
in the power of science inspires our work to
better understand our planet, and the universe.