Astro2020 Science White Paper: What is the lifecycle of gas and stars in galaxy centers?

The closest galaxy center, our own Central Molecular Zone (CMZ; the central 500 pc of the Milky Way), is a powerful laboratory for studying the secular processes that shape galaxies across cosmic time, from large-scale gas flows and star formation to stellar feedback and interaction with a central supermassive black hole. Research over the last decade has revealed that the process of converting gas into stars in galaxy centers differs from that in galaxy disks. The CMZ is the only galaxy center in which we can identify and weigh individual forming stars, so it is the key location to establish the physical laws governing star formation and feedback under the conditions that dominate star formation across cosmic history. Large-scale surveys of molecular and atomic gas within the inner kiloparsec of the Milky Way (~10 degrees) will require efficient mapping capabilities on single-dish radio telescopes. Characterizing the detailed star formation process will require large-scale, high-resolution surveys of the protostellar populations and small-scale gas structure with dedicated surveys on the Atacama Large Millimeter/submillimeter Array, and eventually with the James Webb Space Telescope, the Next Generation Very Large Array, and the Origins Space Telescope.

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