Mary Precious Feutsop Ngouane
MIT Department:
Physics
Faculty Mentor:
Kiyoshi Masui
Research Supervisor:
Ryan Raikmann
Undergraduate Institution:
Carleton College
Biography
Mary Precious is a Physics and Computer Science major at Carleton College, whose research runs from galaxy evolution to cosmology. She uses cosmological simulations to trace how merging dwarf galaxies shaped the Milky Way, which she has shared at multiple conferences, including an oral talk at the American Astronomical Society, and is now writing as the first author. Precious has also worked in experimental optics with light-shaped polymers, building and characterizing optical instruments and the systems that push their precision. This summer, as an MSRP researcher at MIT, she is using fast radio bursts to track down the universe’s missing baryons. Precious is also passionate about making physics inclusive and accessible. That commitment led to her role as a student ambassador for the American Physical Society and as an APS Advocacy Champion. She works to advance science policy and broaden support for physics and its future.
Where are the Missing Baryons?: A Modular Framework for FRB
Cross-Correlation Analyses
Mary Precious Ngouane1, Ryan Raikman2,3 and Kiyoshi Masui2,3
1Department of Physics and Astronomy, Carleton College
2Department of Physics, Massachusetts Institute of Technology
3MIT Kavli Institute for Astrophysics and Space Research
A large fraction of the universe’s ordinary matter resides as diffuse ionized gas that galaxy surveys cannot detect directly. Fast radio bursts (FRBs), millisecond flashes of radio light from extragalactic sources, let us probe this gas. Free electrons along each signal’s path delay its frequencies by a measurable amount, the dispersion measure (DM). Cross correlating FRB DMs and positions with galaxy maps has recently yielded first constraints on how this gas is distributed around galaxies. This project consolidates and optimizes the theoretical modeling for these analyses into an importable package, which takes a description of the universe and predicts how DM and FRB positions trace galaxies in the sky. Because DM traces the gas along the line of sight, a stronger small-scale correlation with galaxies means the gas sits in halos, while a weaker one means feedback has expelled it. Independent code implementations validate every statistic to percent-level agreement, the fitting code runs five times faster, and automated tests confirm identical results. To interpret measurements, the framework supports standard cosmological calculations, extended analytic methods reaching smaller scales, and simulations that follow gas physics directly. Testing these models against data brings us closer to where the universe keeps its ordinary matter.
