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.
