We re-analyse a combined 198 ks Chandra observation of NGC 4696 , the brightest galaxy of the Centaurus cluster .
We extract temperature and metallicity profiles from the data , and we confirm the presence of a sharp drop in iron abundance , from \sim 1.8 Z \odot to \sim 0.4 Z \odot , within the central 5 kpc of the cluster .
We estimate that this central abundance drop corresponds to a total “ missing ” iron mass of 1.4 \times 10 ^ { 6 } M _ { \odot } .
We propose that part of this missing iron is locked up in cool ( \sim 19 K ) , far-IR emitting dust , as found by Spitzer and Herschel observations .
This can occur if the iron injected by stellar mass loss in the central region is in grains , which remain in that form as the injected dusty cold gas mixes and joins the cold dusty filamentary nebula observed within the same region .
The bubbling feedback process observed in the cluster core then drags filaments outward and dumps them at 10–20 kpc radius , where the metallicity is high .