AR 12632 (Archival Research)

Fri Dec 8 10:01:42 GMT 2023

Principal Investigator: Gurtina Besla
PI Institution: University of Arizona
Investigators (xml)

Title: Modeling the Star Formation Histories and Kinematics of the Magellanic Clouds
Cycle: 19

One of the most surprising results to come out of HST in recent years is the proper motion measurements of the Large and Small Magellanic Clouds, which indicate that the Magellanic Clouds {MCs} are moving significantly faster than previously believed {Kallivayalil et al. 2006a,b}, and may be on their first infall towards the Milky Way {MW} {Besla et al. 2007}. Such a drastically different orbital history overturns a paradigm that has existed for decades and is consequently a controversial result. A detailed theoretical study illustrating the compatibility of these measurements with our understanding of the properties {kinematic structure and star formation histories} of the MCs is thus critical to the verification of these measurements and the establishment of HST as a reliable method of determining high precision proper motions. Furthermore, as the closest pair of interacting dwarf galaxies to the MW, detailed comparisons between the observed star formation histories {SFHs} of the MCs and simulations of the star formation induced by tidal encounters between them will provide a theoretical basis for explaining the various SFHs of dwarf galaxies observed by HST in our local volume. Similarly, models of the kinematic evolution of the gaseous and stellar components of the MCs will help to identify the role of dwarf-dwarf interactions to the evolution of dwarf galaxies into different morphological types {dSph vs. dIrr}. These studies will be extended to various environments, including groups of galaxies and clusters, and compared to, e.g., ACS surveys of dwarfs in the Virgo and Coma clusters in order to assess the impact of environment on the evolution of dwarf galaxies.