33) The Orbital Histories of Andromeda’s Satellite Galaxies

Abstract: High-precision astrometric data from space observatories, such as the Hubble Space Telescope, and ground-based interferometers, such as the Very Long Baseline Array, are revolutionizing our ability to study galaxies in the Local Group. 6D phase space measurements (3-dimensional position and velocity) now make it possible to rewind the clock and trace the orbital histories of nearly half of all Local Group satellites to their cosmic origins in the early Universe. While 6D phase space information is available for more than 40 of the Milky Way’s satellite galaxies, just four of Andromeda’s 35 known satellites have available phase space information to date. I will discuss the orbital history of Andromeda’s most massive satellite galaxy, M33, and draw parallels with the Milky Way’s most massive satellite galaxy, the Large Magellanic Cloud. Additionally, I will highlight more recent work on the orbits of two of Andromeda’s dwarf elliptical satellite galaxies, NGC 147 and NGC 185, which have long been posited to be binary galaxies. NGC 185 and NGC 147 have also previously been identified as members of the Great Plane of Andromeda (GPoA), a thin plane encompassing nearly half of Andromeda’s known satellite galaxies. With our recent results, we can now assess whether the GPoA is a dynamically coherent structure and draw comparisons with the Milky Way’s plane of satellites, thereby uncovering the role of satellite galaxies in the assembly history of their hosts.

Bio: "Ekta Patel is a Miller Fellow at UC Berkeley’s Miller Institute for Basic Research. She utilizes simulations and models to understand the dynamics of satellite galaxies orbiting around our own Milky Way and its neighboring galaxy, Andromeda. Ekta graduated from New York  University in 2014 with a B.A. in Physics. She completed her Ph.D. in Astronomy & Astrophysics in 2019 under the supervision of Professor Gurtina Besla at the University of Arizona where she was also an NSF Graduate Research Fellow. Ekta enjoys engaging with her local community through science communication and has been involved in a variety of outreach programs in Tucson, AZ and the San Francisco Bay Area. "