Over the last 20 years, six major infrared galactic surveys (2MASS, spitzer/glimpse, ukidss-galactic plane survey, VVV, wise, and apogee) have yielded an enormous wealth of information on the…

This federal contract award is a $303,768.59 grant from the National Aeronautics and Space Administration (NASA) to the University of Wisconsin System, with the University of Wisconsin-Whitewater as the prime awardee. The grant supports research to create photometrically-selected catalogs of red clump and red giants in the Milky Way galaxy using data from major infrared surveys. These catalogs will be used to produce three-dimensional maps of the stellar mass distribution in the galactic disk, bulge, and bar. The research aims to address key unresolved questions about the structure of the Milky Way, including the nature of non-axisymmetric features like the galactic bar and spiral arms. The results will inform the planning of future NASA missions such as SPHEREx and WFIRST. This is an unset-aside grant awarded directly to the University of Wisconsin System, a public university system in Wisconsin that has participated in a range of federally-funded research and development efforts across various domains.

Over the last 20 years, six major infrared galactic surveys (2MASS, spitzer/glimpse, ukidss-galactic plane survey, VVV, wise, and apogee) have yielded an enormous wealth of information on the stellar and star-forming content of the disk, bulge, and bar(s) of the milky way. Using data from these surveys, we will create photometrically-selected catalogs of red clump and red giants candidates to trace the stellar mass of the milky way galaxy. We will validate these samples using spectroscopic information from apogee and parallax information from gaia. A second catalog of stellar proper motions will also be created using two epochs of spitzer observations along the galactic plane taken a decade apart to search for non-axisymmetric stellar motions due to the galactic bar(s). These catalogs will be used to produce non-parametric three-dimensional maps of the stellar mass of the disk, bulge, and bar(s) of the galaxy. These maps will then be used to address the following unresolved questions of milky way galactic structure: (1) what is the amplitude and distribution of non-axisymmetric stellar density in the inner galactic disk due to spiral structure; (2) what is the density structure of the stellar disk interior to 4 KPC where gas tracers show a hole ; (3) does the milky way have an inner or outer stellar ring; (4) what is the three dimensional structure of the truncated" and warped stellar disk and the outer exponential (?) scalelength of the stellar disk beyond the truncation distance. The results of this research will be used to inform the planning of future NASA missions, principally spherex and wfirst.