Observational approach
How I investigate this question
I compare resolved X-ray, optical emission-line, radio, and molecular-gas structures across nuclear, circumnuclear, and kiloparsec scales to locate measurable changes in the host-galaxy gas.
Observatories
ChandraHubbleVLTALMAeMERLIN
Physical interpretation
What the observations allow us to test
Ionization or morphological alignment identifies an AGN influence, but galaxy-scale feedback requires evidence that the nucleus changes the gas distribution, dynamics, or energy budget.