Mark Gaskins

Mark Gaskins

Biography

Mark Anthony Gaskins is an Applied Physics student at North Carolina A&T State
University with interests in computational physics, astrophysics, dark matter, and data-driven
research. He is participating in the MIT Summer Research Program, where he is conducting
theoretical astrophysics research on dark matter and the evolution of stellar structures in the
Milky Way. Mark Anthony has also gained research experience at Duke University’s HIGS
facility, where he participated in a nuclear physics experiment in a particle accelerator-based
research environment. Outside of physics, he has worked as a software developer and educator,
teaching programming and leadership through The Hidden Genius Project and developing
AI-powered educational software with ScholarPrep Nation. Mark Anthony hopes to pursue
graduate study and continue developing as a researcher. He is passionate about combining
scientific research, technical problem-solving, and mentorship to advance discovery and
support the next generation of STEM students.

Constraining Dark Matter with the Gaia Snail
Mark Anthony Gaskins II1, Zeineb Mezghanni2,3, Elliot Davies3 and Lina Necib2,3
1Department of Physics, North Carolina Agricultural & Technical State University
2Department of Physics, Massachusetts Institute of Technology
3Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology

Dark matter (DM) provides the gravitational scaffolding for galaxy formation. Because
it only interacts with baryonic matter through gravity, its properties must be inferred from
its dynamical influence on stars. Data from the Gaia space mission revealed a spiral-shaped
overdensity in the (z, vz) space of solar neighborhood disk stars in the Milky Way (MW),
dubbed the Gaia Snail. This discovery is a signature of phase mixing following a gravitational
disturbance caused by the passage of the Sagittarius dwarf galaxy (Sgr). The open question of
whether the type of DM affects Snail’s properties may help provide insight into the particle
nature of DM. To connect DM physics to observable stellar motions, we create MW-like
galaxies with a DM halo, a stellar disk, and a bulge using the GalIC code. We simulate the
impact of a Sgr-like merger using GIZMO N-body simulations, reproducing the Snail in the
stellar disk and comparing its evolution across DM self-interaction cross sections. Preliminary
results show similar evolution across SIDM cross sections of 0.5-5.0 cm2/g, with typical action
differences below 3% and vertical-period differences below 0.4%. This work can guide future
modeling efforts to constrain dark matter physics using the Gaia Snail.