A significant fraction of the energy in the universe has been absorbed and re-emitted by dust, in dusty star-forming galaxies (DSFGs). Most of the star formation in the universe at cosmological redshifts between 2 and 3 may have taken place in such galaxies and emitted no visible or ultraviolet light because of dust obscuration. Using the NSF- and DOE-funded South Pole Telescope (SPT), the proposing team has identified approximately 100 bright DSFGs, all of which are magnified and brightened by gravitational lensing. They now intend to use the Atacama Large Millimeter/Submillimeter Array (ALMA) to observe these galaxies, obtaining spectroscopic redshifts, measuring elemental abundances, and inferring the distribution of dark matter. The goals are to determine the distribution of DSFGs in redshift, the physical conditions in their interstellar media, and the mass function of dark matter substructure. As a broader impact, the proposers intend to develop new interferometric analysis tools that incorporate self-calibration as a modeled uncertainty for gravitationally lensed objects. The project will support the work of two graduate students, and the PI will conduct outreach presentations and develop undergraduate laboratory exercises on interferometry.
