CAREER: Exploring the Invisible Universe With Milky Way Dwarfs and Streams

Haverford College, Haverford PA

Investigators

Abstract

Dr. Willman will use Milky Way stellar streams and dwarf galaxies to study the Galaxy's dark matter sub-halos and formation history. She will implement a photometric technique to mitigate contamination from unresolved galaxies in Sloan Digital Sky survey and Dark Energy Survey point source catalogs. She will apply new techniques to optical (Sloan Digital Sky Survey, Dark Energy Survey) and infrared (UKIDSS) datasets to study known stellar streams with higher fidelity and to reveal the presence of previously unseen streams and dwarfs in previously unmapped Milky Way volume. The data are already publicly available for both the Sloan Digital Sky Survey and UKIDSS. The Dark Energy Survey is scheduled to begin survey operations in 2012. Dr. Willman will also use N-body and N-body + SPH simulations to explore a possible new method to "see" purely dark sub-halos. She will investigate the merging histories of the Milky Way's dwarf galaxies and possible observational signatures thereof. This work provides a direct approach to astronomically measure the properties of dark matter on the smallest possible sub-galactic scales - a major problem facing observational cosmology. It will also leave the field well-poised for the upcoming wide-field optical and infrared surveys. A postdoctoral researcher and undergraduate students will be trained as they participate in this research and in related public outreach. The postdoctoral researcher will also engage in closely mentored undergraduate teaching experiences at Haverford College. Dr. Willman will lead an undergraduate seminar in science diversity in Years 1, 3, and 5. Students and Dr. Willman will collaborate on developing Haverford's student-run Strawbridge Observatory public program. Numerous undergraduates will have the opportunity to participate in a student-led research program based on KPNO 0.9m telescope observations. Dr. Willman will also release star catalogs for the Sloan Digital Sky Survey and the Dark Energy Survey informed by broad-band photometry.