The Genealogy of the Milky Way and the search for the missing Dark Matter

Event Date: 
March 7, 2023
Lina Necib

Galaxies form and grow by merging with other galaxies, making the formation history of a galaxy resemble that of a family tree. Our galaxy, the Milky Way, is no exception, and with recent telescopes like Gaia, we are able to build the Milky Way's family tree. We find that a large galaxy, called Enceladus after the Greek giant son of Gaia, merged with the Milky Way about 10 billion years ago, leaving a large trail of old stars. However, these mergers did not only bring in stars, but also something unseen, the Dark Matter, a hypothesized matter making up 86% of the local universe but is yet to be directly detected. These ethereal Dark Matter particles have different dynamics from the ones born in the Milky Way, affecting Dark Matter searches by creating local dark hurricanes. In this talk, I will show you amazing videos of simulated merging galaxies, and emphasize how these mergers have direct implications on our searches for the mysterious Dark Matter.

Speaker Bio: 
Lina Necib is an astroparticle physicist exploring the origin of Dark Matter through a combination of simulations and observational data that correlate the dynamics of Dark Matter with that of the stars in the Milky Way. She has investigated the local dynamic structures in the Solar neighborhood using the Gaia, contributed to building a catalog of local accreted stars using machine learning techniques, and discovered a new stream called Nyx after the Greek Goddess of the Night. Necib is interested in employing Gaia in conjunction with other spectroscopic surveys to understand the Dark Matter profile in the local solar neighborhood, the center of the Galaxy, and in dwarf galaxies. After obtaining a bachelor’s degree in Mathematics and Physics from Boston University in 2012 and a PhD in theoretical physics from MIT in 2017, Necib was a Sherman Fairchild fellow at Caltech, a Presidential Fellow at the University of California Irvine, and a Fellow in Theoretical Astrophysics at Carnegie Observatories. She returned to MIT in 2021 as an assistant professor in the Department of Physics and a member of the MIT Kavli Institute for Astrophysics and Space Research.