Brian T. Cook

About

Welcome! My name is Brian Cook; I am working on my PhD in astrophysics at the University of North Carolina at Chapel Hill. Generally speaking, I am interested in dense star clusters, Galactic archaeology, and near-field cosmology. Before coming to Carolina, I received my BS in astrophysics from the University of Michigan and my MSc in astronomy from the Sterrewacht in Leiden. You can learn more about my research interests elsewhere on this site.

Research

I briefly describe my previous research experience (and give a broad introduction to each topic) here.

N-body solvers and Star Clusters

There are a variety of ways to simulate a collection of self-gravitating systems, and globular clusters push the boundaries of what can be done computationally. Brute-force, O(N^2) approaches take many months to complete on a supercomputer due to the dramatically varying spatiotemporal scales present in the resolution of the underlying dynamics. I led the development of KRIOS (recently introduced at the 56th DDA meeting), a new Monte Carlo N-body code specifically designed for modeling the evolution of globular clusters in a host galaxy like the Milky Way. The forthcoming code papers will describe the code and demonstrate its ability to act as an intermediary between direct N-body and particle-spray codes.

Galactic Archaeology

Galactic archaeology is the branch of research devoted to determining the formation history of the Milky Way. Galaxies form in what is known as a hierarchical process; smaller galaxies are accreted by larger galaxies, which in turn causes the larger one to grow. As the smaller galaxy is tidally stripped, it leaves behind signatures in the form of objects like stellar streams and globular clusters.

As a summer intern at MIT Lincoln Lab, I developed a routine for identifying substructure in the Milky Way comprised of RR Lyrae variables, a popular standard candle in this context, based on hierarchical clustering. You can learn more about our results in Cook et al. (2022). I have been expanding on this effort with the new Gaia DR3 release with an eye towards a more general identification routine for forthcoming surveys.

Near-field Cosmology

It is theorized that during a period of rapid inflation after the Big Bang, small quantum fluctuations were forced onto macroscopic scales. Cosmologists can use observations of the cosmic microwave background to map these overdense anisotropies in the Universe, in addition to determining the abundances of things like baryonic matter and dark energy. With this set of initial conditions, a wide set of cosmological simulations have been developed.

These simulation suites are comprised of state-of-the-art algorithms that treat astrophysical phenomena operating on different length and time scales simultaneously. The outputs can then be analyzed to test the effects of underlying physics theories (e.g., AGN feedback, small-scale DM distribution) on observables.

During my first year in Leiden, I analyzed low-mass, star-forming galaxies produced by the EAGLE simulations. My first project presents an analysis of the circumgalactic medium (CGM) of these galaxies; often defined as the material gravitationally bound to the galaxy but outside of the disk, the CGM is critical to understanding galaxy formation and evolution.

CV

Curriculum Vitae.

Contact

I can be reached by e-mail (btcook [at] unc.edu).

Links

LinkedIn, GitHub, Google Scholar.

Elements

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