Collaborative Research: Tests of Dark Matter physics with isolated dwarf galaxies in the Dark Energy Survey

University Of Chicago, Chicago IL

Investigators

Abstract

One-quarter of the Universe consists of a form of matter whose nature is unknown --- dark matter (DM). The most striking prediction of the leading cold dark matter (CDM) paradigm is the existence and abundance of small collapsed clouds of dark matter, called halos. Small “dwarf” galaxies are expected to live in these small DM halos. By using observations of dwarf galaxies to count halos, the investigators will test CDM models. The investigators will complete a census of dwarf galaxies near our Milky Way Galaxy. With these observations, the investigators will search for a connection between galaxies and DM halos. The investigators will share the exciting story connecting galaxies to DM through a planetarium show developed in collaboration with the Ohio State University’s Slettebak Planetarium. The investigators will also assess and improve an early start summer program for undergraduates from underrepresented groups. The investigators will use a combination of optical data from the Dark Energy Survey (DES) and radio data from the Parkes-IMAGINE atomic hydrogen survey to detect and characterize nearby dwarf galaxies that contain as few as a million solar masses in gas and stars. They will use this census of dwarf galaxies to build theoretical models connecting dwarf galaxies with the dark matter halos that they inhabit. They will explore both isolated dwarf galaxies and ``satellite” galaxies orbiting more massive galaxies. Because much of the existing work on the connection between dwarf galaxies and their DM halos focuses on satellite galaxies, we must determine how the evolution of the stars and gas in satellite galaxies affects the matching between galaxies and their halos. The investigators will build a semi-empirical theoretical framework to interpret the data in the context of CDM. The investigators will use a variety of techniques, including surface-brightness fluctuation distance measurements on wide-field imaging data, automated dwarf galaxy and globular cluster identification and cross-matching between the stellar and atomic gas components of small galaxies. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.