The project will map the spatial distribution of dust within the Milky Way. Their project traces Galactic structure and star formation, and is a tool for correcting for interstellar extinction. Previous work on dust structure has focused primarily on the projected density of dust, yielding two-dimensional maps of the dust column density across the sky. Their new approach is to produce a dust map is to measure stellar extinction directly. By combining distance and extinction estimates for a large number of stars across the sky, it is possible to produce a three-dimensional map of interstellar extinction. PanSTARRS-1 has been surveying 3ð steradians of the sky, producing a point-source catalog of more than 500,000,000 stars in five passbands They propose to produce a high-resolution three-dimensional dust map across three-quarters of the sky using PanSTARRS-1 photometry, and to make it available to the public.
Their 3-D map will allow estimation of distances to individual dust clouds and filaments, and better utilize information from CO and HI surveys, which suffer from velocity-distance degeneracy. Such a map also improves the understanding of the 3D distribution of stars, allowing for less biased searches for dwarf galaxies and tidal streams. When the researchers combine hundreds or thousands of stars along the same line of sight (in one spatial pixel) they provide a powerful constraint on the dust distribution along the line of sight.
A graduate student will carry out part of this research and will be trained in developing and applying theory, observation, and statistical analysis tools to problems in Galaxy formation and evolution.
They will release the data for use via the World Wide Telescope (WWT). The WWT is a leading educational tool bringing the awe and beauty of astronomy to the public. It allows the user to zoom and pan around the sky, seamlessly merging full-sky maps at various wavelengths with detailed observations of particular objects. WWT has a 3D mode, in which the user can move through the 3D structure of the Solar System, Galaxy, and large-scale structure maps provided by redshift surveys. The PI has previously contributed the SFD dust map and H-alpha maps to the WWT project, and expects to contribute a 3D dust map as soon as possible.
