SURF

Hunter Martin

Impact of Baryons on Intrinsic Galaxy Alignments using Cosmological Simulations

One of the principal probes of cosmology is weak gravitational lensing whereby gravitational effects of mass bend the path of light. This causes small but correlated distortions in the images of distant galaxies which we can measure and then use to study the distribution of matter over cosmological distances and time scales. However, one of the fundamental assumptions of this method is that galaxy shapes (which we can model as ellipses) are randomly oriented in the universe, and that these distortions serve to align them. But what happens when the galaxies are already aligned before the distortion? My area of study is on these intrinsic alignments and how to disentangle their alignments from the alignments caused by lensing. My project involves working with data from large cosmological simulations to measure how the presence of nearby matter, especially gas and stars, causes the galaxy shapes to intrinsically align. The goal of this project is to produce better models for intrinsic alignments. Such models will lead to more accurate analysis of weak lensing measurements and will also help in understanding the physics of galaxy formation and evolution.

Message to Sponsor

I would like to sincerely thank the McKinley Fund for providing the financial resources that allowed me to continue my work on this project this summer. I truly feel as though my work this summer has helped me develop as a physicist. After working on this project for about a year, this summer allowed me the opportunity to apply myself and really try to learn and understand the theory behind my work, and how to connect it to the larger research area as a whole, as opposed to going through the motions of writing code and performing calculations without much understanding as to why these calculations were important. Furthermore, the opportunity to present my work at the SURF conference was invaluable, as it forced me to zoom out and look at the big picture of my research in order to explain it to a general audience. That experience alone allowed me to have incredibly insightful conversations with my advisor that I might not have had otherwise. This summer helped to further cement my interest in the field of cosmology, and I do intend to continue following this interest well into graduate school if given the opportunity. The opportunity I was given this summer allowed me to attack my research project with renewed vigor, and was also able to move me very close to publishing my first paper. My newfound understanding of the nature of my work has also allowed me to want to actively seek out opportunities to present my work, and to ignite the same passion for this field in other people like my project has.
  • Major: Mathematics and Physics
  • Sponsor: McKinley Fund
  • Mentor: Sukhdeep Singh