The Inner Workings of Starbursts and Their Winds

Astronomers have realized since the mid-1990s that the star formation in the Universe has not been constant, and that in fact, the star formation rate per unit volume has steadily decreased since attaining a peak at z ~ 2. While still not completely understood, this is thought to be due to a combination of a steady decrease in the inflow of pristine gas from the Cosmic Web, a more efficient mode of star formation in the past, and the effects of large-scale galactic winds from regions of intense star formation.

This research centers on high spatial resolution sub/millimeter wavelength line and continuum observations of local starburst galaxies, where high efficiency star formation and associated wind-driven outflows occur, in order to better understand the physical processes driving star formation at its peak epoch (i.e., "cosmic noon"). This project will support two research graduate students and one undergraduate student, the latter participating in a side project working to increase STEM participation among minority populations.

Using high angular resolution sub/millimeter and radio observations of the local starburst galaxies NGC 253, M82, and NGC 4945, this project will advance knowledge of the physical processes that shape their evolution. A key goal of this research is a better understanding of the physics of star formation “quenching" through (e.g.) observationally constraining the entrainment of cold gas in galactic scale wind-driven outflows powered by starbursts and the physical conditions in the outflowing gas that influence its fate.

The research team will also measure basic properties of young, massive starburst clusters and improve our knowledge of the fraction of stars that form in them and determine how molecular gas properties vary among starburst galaxies. All these results will lead to more physically realistic numerical models of galaxy evolution. The researchers will place these results in the context of main sequence galaxies at the peak of cosmic star formation by comparing the physical state of the local starbursts with spatially resolved molecular properties in a new large galaxy sample (DYNAMO).

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.