RII Track-4:NSF: Probing the Dark Sector through Telescopes

University Of New Mexico, Albuquerque NM

Investigators

Abstract

In the last three decades, detailed observations of the night sky with powerful telescopes have revealed physical phenomena that appear extremely important for the evolution of the cosmos but have never been observed in the laboratory here on Earth. One such phenomenon is the existence of dark matter, a mysterious constituent of the Universe that is about five times as abundant as the matter familiar to us in our everyday life. Its fundamental nature remains one of the most important questions in particle physics and cosmology. As some of the most dark-matter-dominated objects in the night sky, small satellite galaxies orbiting our own Milky Way galaxy are ideal laboratories to study its properties. This Research Infrastructure Improvement Track-4 EPSCoR Research Fellows project will provide a fellowship to an Assistant Professor and training for a graduate student at the University of New Mexico. This work will be conducted in collaboration with researchers at the University of California, Irvine. The project will allow the PI to gain critical expertise during two visits at the University of California, Irvine. As part of this award, the co-hosts from UC Irvine will come visit the University of New Mexico to give colloquia and public talks, providing a networking opportunity to our local graduate students. The PI will also share his expertise about the mysteries of dark matter by giving a public talk in Irvine. Workforce training will be provided to a graduate student as part of this award. Researchers will use detailed observations of the Milky Way satellites to explore the fundamental properties of dark matter. Since these small satellite galaxies reside within some of the least massive dark matter halos that we can directly probe, they are ideal laboratory for testing whether the standard cold dark matter predictions extend all the way to these tiny scales. During two extended visits to the University of California, Irvine, the PI and graduate student will collaborate with expert particle astrophysicists there to build the necessary numerical infrastructure to forward-model the impact of dark matter physics on the observed properties of the Milky Way satellites. Project analysis will focus on two key properties that could indicate a deviation from the cold dark matter scenario: a suppression of structure at the smallest scales and the presence of significant dark matter self-interaction within the small halos surrounding these satellites. With the forward model in hand, researchers will use current observations of the Milky Way satellites to constrain these two key properties and test, for the first time with this level of precision, whether dark matter is really cold and collisionless at these scales. We will finally perform forecast for what future data from the Vera Rubin Observatory will be able to contribute to these constraints. Project outcomes have potential to lead to the most thorough picture to date of what the population of Milky Way satellites can tell us about the physics of dark matter. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.