Collaborative Research: Exploring Galaxy Evolution at High Resolution with Gravitational Lensing and ALMA

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

This project studies the growth of massive galaxies in the first few billion years after the Big Bang. The target galaxies are magnified by "gravitational lensing," the bending of light around intervening galaxies, which allows them to be detected more easily and studied in greater detail than other galaxies at similar distance. The primary data come from the Atacama Large Millimeter/submillimeter Array (ALMA). With these and other data, the team will determine how these galaxies form stars so rapidly and shut down their formation so quickly, look for evidence of black hole growth in the galaxies, determine the number of such galaxies in the Universe to see how they affect the overall history of cosmic star formation, and test the modern cosmological paradigm by exploring their lensing in great detail. This award will support the teaching of astronomy through examples from this research to fifth grade classes in Illinois, hands-on radio astronomy technology experiences for high school students in Arizona, and training of undergraduate and graduate students in advanced techniques of radio astronomy and interferometry. The project will pursue several goals using gravitationally lensed galaxies discovered by the South Pole Telescope: (1) determine the triggering mechanisms for the most intense star formation events in the high redshift Universe, (2) study the regulation and termination of star formation by observing gas dynamics and outflows, (3) study the assembly of massive elliptical galaxies by determining stellar masses, star formation rates, and gas content in such galaxies at very high redshift, (4) explore the coevolution of black hole accretion and stellar mass assembly in these objects, (5) measure metal enrichment with far-infrared atomic lines, (6) determine the space density of these extreme starbursts and connect them to state of the art galaxy formation simulations, and (7) identify substructure in the halos lensing these galaxies to test the predictions of current cosmology models. These goals are largely achievable based on the data already promised in ALMA cycles 3 and 4 using the advanced interferometric analysis tools that have been built up over the past several years. The team incorporates both observers and theorists to ensure that the lessons derived from these high-resolution views of the early Universe can be compared against and fed back into state-of-the-art galaxy formation simulations.