Ian Padgett was born and raised in Tallahassee, Florida. While in Florida, he gained a lasting interest in space by watching the final space shuttle launches at Kennedy space center and joining his local astronomy club. Paired with a want to explore, this led him to move to Hawaii in 2019 to pursue a Bachelor of Science in Astrophysics at University of Hawaii at Manoa. While there, he started introductory research projects involving Pan-STARRS and currently works with gravitational lens modeling. Ian intends to pursue an observing position on Mauna Kea to gain experience and continue to do post bachelor research before pursuing a doctorate in astrophysics in Europe. Ian loves public outreach events, snorkeling, photography, and sweet tea!
Home Island: Mainland
High School:
Institution when accepted: University of Hawai’i at Manoa
Project Site: Institute for Astronomy, Hilo: IfA, Hilo, Big Island HI
Mentor: David Jones
Project Title: Characterizing Linear Bias Between Galaxy and Dark Matter Distributions
Project Abstract: The universe is expanding at an ever-accelerating rate; however, the value of this rate (the Hubble constant, or H0) is not agreed upon and is currently the subject of one of the largest debates in cosmology. One way to measure H0 is by measuring the velocity at which galaxies move away from us divided by their distance. However, galaxy velocities are also gravitationally influenced by local dark matter; thus, to measure the global expansion velocity, small-scale velocity perturbations resulting from local gravitational influences (peculiar velocities) must be accounted for. The aim of this project is to use cosmological simulations to understand whether peculiar velocity predictions are reliable. Peculiar velocities are primarily dependent on dark matter, which we cannot directly observe. In order to get a peculiar velocity measurement, the dark matter distribution is inferred from the visible galaxy distribution. To test how well this relation is calibrated, we can use large-scale galaxy simulations, such as IllustrisTNG. In these simulations, the dark matter content of the galaxies is known; thus, a true peculiar velocity can be measured. Our results will improve our understanding of peculiar velocities in our local Universe which in turn will improve the accuracy of H0 measurements.