Investigating Aeroacoustic Sources in a Subsonic Jet

George, W\"{a}nstr\"{o}m, and Jordan (2007) suggested an alternative approach to identifying aeroacoustic sources. Through this method, contributions to the pressure field are effectively separated into three separate terms. One term is unique in that it present only in compressible flows. This compressible term has been argued to be the only term that can radiate acoustically. An investigation into this approach is presented in the specific case of a subsonic jet. Particular attention is paid to the compressible term and its interaction with the mechanism that is responsible for the hydrodynamic pressure in an incompressible flow. We extend our thanks to Jonathan B. Freund for access to data from his DNS jet simulation.