094298

Current studies on ICM cooling are limited to systems showing mature AGNactivities leading to a biased understanding of the cooling process and anincomplete understanding of the feedback cycle especially in the short durationprior to AGN ignition by the cooled gas. To this end we propose deep RGSexposure of RXC J1539.5-8335 a rare case of a cluster in the pre-feedback phaseas indicated by multi-wavelength observations to investigate its massivecooling gas undisturbed by AGN heating. With its multi-phase ICM characterizeddown to < 0.3 keV we aim to build a full image for the cooling process withoutheating disruption for the first time thus providing insights into refining theself-regulated feedback model. [truncated! Please see actual data for full text]