How do galaxies stop forming stars?

I use JWST data to trace neutral gas outflows and uncover their role in shutting down star formation in the early Universe.

• Constructed a quiescent galaxy sample at 2.0 < z < 5.0 from the JWST NIRSpec catalog using Hα equivalent width, separating quiescent, green-valley, and star-forming populations.
• Built matched spectroscopic–photometric datasets and performed SED fitting with Prospector to derive stellar continua and physical parameters.
• Subtracted stellar continua and performed spectral stacking of residual spectra to enhance Na I D absorption features.
• Measured equivalent widths and velocity offsets of stacked absorption lines to probe neutral-gas outflows.