Collaborative Research: ACES Galactic Center Mass Flow

University Of Florida, Gainesville FL

Investigators

Abstract

The center of our Milky Way Galaxy is dynamic, with stars forming in clouds of molecular gas. The pressure on the flow of gas regulates the star formation process. As gas moves in and out of galaxy centers, the galaxies grow and change. Gas flows form new stars, feed the central supermassive black hole, and eject mass in energetic outflows. The Milky Way center is the nearest and best laboratory for studying the life cycle of gas flows. The team of investigators will make the first high resolution maps of gas across the entire Milky Way center. By simultaneously mapping the gas motions and the distribution of star formation, the team will reveal how these processes are connected. This will be a significant advance in our understanding of the physics that drive the activity cycle in all galaxy centers. In addition, this work will support the creation of a program to support underrepresented students in the transition year between undergraduate and graduate school. Students will be integrated into this research collaboration and will receive data analysis training and targeted mentoring. A key research area in the National Academy’s “Pathways to Discovery in Astronomy and Astrophysics for the 2020s” report is the study of cosmic mass flows on large and small scales. The center region of the Milky Way, called the Central Molecular Zone (CMZ) is a unique ecosystem for these studies. The CMZ is the only location where gas flows from kilo-parsec scales down to proto-stellar disks can be explored simultaneously. The team will lead critical parts of the ALMA CMZ Exploration Survey (ACES), an ALMA large program to survey the entire Milky Way center and will make the first comprehensive measurement of mass flows in a galaxy nucleus. This program represents an unprecedented combination of a large observing area with high-resolution imaging. The investigators will conduct a complete census of the mass in molecular gas and protostars spanning four orders of magnitude in size scale and characterize the associated gas kinematics with more than a dozen molecular tracers. Products of this work will include a catalog of extended (diffuse) and compact (dense) mass components in the CMZ, as well as a complete kinematic model of gas motions through the CMZ. Ultimately, this project will make the definitive measurements of the rates of inflow, outflow, star formation, and accretion toward the central supermassive black hole. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.