Collaborative Research: Absorption and Emission Line Probes of Galactic Winds with eBOSS

Star formation is a very inefficient process with only 5% - 20% of the gas converted into stars. Galactic outflows play an important role in self-regulating star formation and maintaining the low efficiency. The Principal Investigators (PIs) Tremonti, Diamond-Stanic and Lundgren, will use observations of 300,000 galaxies from the extended Baryon Oscillation Spectroscopic Survey (eBOSS) to measure the physical properties of galaxies, including the outflowing gas, to investigate the underlying physics responsible for the low efficiency of galactic star formation.

To promote student engagement in science technology engineering and mathematics (STEM) the PIs will design a set of web-based computational astronomy activities suitable for both high school and undergraduate students using the eBOSS survey data. The team will disseminate these activities through a series of workshops for educators and evaluate their effectiveness in improving students’ data literacy, computational skills, and interests in science.

The team will create and analyze high-quality spectra based on stacks of thousands of individual eBOSS galaxy spectra at redshifts of 0.4 < z < 1. They will compare outflowing gas traced via absorption lines to outflowing gas traced via emission lines to test whether these methodologies are measuring the same or different components of the outflow. They will also measure the geometry and spatial extent of the outflows through backlighting experiments that use the spectra of background quasars and use this information to estimate robust mass outflow rates.

The team will identify clear empirical relationships between galactic outflows and galaxies. They will release a catalog of stacked spectra and associated physical properties to the public.

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.