Possible depletion of metals into dust grains in the core of the
  Centaurus cluster of galaxies
  We present azimuthally averaged metal abundance profiles from a full,
comprehensive, and conservative re-analysis of the deep ($\sim$800 ks total net
exposure) \textit{Chandra}/ACIS-S observation of the Centaurus cluster core
(NGC\,4696). After carefully checking various sources of systematic
uncertainties, including the choice of the spectral deprojection method,
assumptions about the temperature structure of the gas, and uncertainties in
the continuum modeling, we confirm the existence of a central drop in the
abundances of the `reactive' elements Fe, Si, S, Mg, and Ca, within
$r\lesssim$10 kpc. The same drops are also found when analyzing the
\textit{XMM-Newton}/EPIC data ($\sim$150 ks). Adopting our most conservative
approach, we find that, unlike the central drops seen for Fe, Si, S, Mg and Ca,
the abundance of the `nonreactive' element Ar is fully consistent with showing
no central drop. This is further confirmed by the significant ($>3\sigma$)
central radial increase of the Ar/Fe ratio. Our results corroborate the
previously proposed `dust depletion scenario' , in which central metal
abundance drops are explained by the deposition of a significant fraction of
centrally cooled reactive metals into dust grains present in the central
regions of the Centaurus cluster. This is also supported by the previous
findings that the extent of the metal abundance drops in NGC\,4696 broadly
coincides with the infrared dust emission.
