JWST/NIRSpec IFU Maps AGN Outflow Quenching in Massive z=3-9 Galaxies

{"The GA-NIFS program used NIRSpec IFU in both low- and high-resolution modes to map ionized gas kinematics and stellar populations across six targets spanning starburst- and AGN-dominated regimes. Outflow properties derived from previous R~2700 analysis were cross-matched with pixel-by-pixel SFH fitting, revealing that only the two most massive AGN hosts exhibit clear post-starburst signatures inside 3 kpc. Less massive starbursts at z>5 display continuous star formation despite powerful outflows.","This spatial decoupling indicates that AGN feedback can suppress star formation on ~100 Myr timescales at early epochs, a regime where current hydrodynamical simulations underpredict outflow coupling efficiency. The rejuvenation event in GS20936, dated to 10-30 Myr and spatially offset, further implies merger-triggered gas inflows can temporarily override prior quenching, a process rarely resolved in large-volume runs.","These patterns connect directly to cosmic reionization: massive galaxies with episodic quenching may contribute harder ionizing spectra at earlier times than steady starbursts, altering the topology of reionization bubbles. The absence of quenching signatures in weaker-outflow massive systems underscores that outflow power, not merely presence, drives the observed SFH diversity.","Next steps require deeper IFU coverage of a statistically complete mass-selected sample at z>6 together with ALMA [C II] maps to test whether molecular gas reservoirs are indeed depleted inside the same nuclear radii showing stellar population truncation."}