Collaborative Research: MASSIVE - A Survey of the 100 Most Massive Galaxies within 100 Mpc

Princeton University, Princeton NJ

Investigators

Abstract

One of the key questions scientists are trying to answer is how the very massive galaxies in our Universe were assembled. In order to do that, they must understand both how they are physically organized right now and how they have changed over time. This proposal will complete an ambitious new survey of the 100 most massive nearby galaxies using powerful instruments called integral field units, which allow scientists to obtain information about the composition and physical properties of multiple positions in galaxies all at the same time. Using that information, they can create a three-dimensional map that includes where the stars and gas are located in a galaxy, how they are moving, and what their composition is. They can also determine the mass of the black holes at the centers of these galaxies. The combination of all this information yields important clues to when the galaxies first began to form (how old they are), and how they changed over time, similar to the rings in tree trunks which reveal their ages and information about their growth patterns through the spacing of the rings. In addition, the PI is mentoring talented high school students and exposing them to cutting-edge science research. The Co-PI teaches inmates in New Jersey State Correctional Facilities through the Prison Teaching Initiative. This provides basic math and science training to underserved incarcerated minorities. This proposal seeks to conduct a large integral field spectroscopy survey of 100 of the nearest, most massive elliptical galaxies. Using a combination of wide-field and adaptive-optics-assisted integral field spectroscopy (IFS), this proposal examines all components of these galaxies, from supermassive black holes on 100 pc scales, to stellar populations and kinematics on kpc scales, and dark matter halos on 10-20 kpc scales. This survey probes a mass range that has not been systematically studied to date, and explores a volume more than an order of magnitude greater than that of the ATLAS-3D project. Characterizing the dynamical and structural properties of these massive galaxies is essential for understanding the trends in the mass assembly histories of the majority of stars in the universe, and for elucidating the relationship of these properties to the growth of supermassive black holes. As a part of the study, they will measure the black hole masses for 27 galaxies, which should double the current number in this mass range, and look for direct evidence of a bottom-heavy IMF.