3 years ago

# Possible depletion of metals into dust grains in the core of the Centaurus cluster of galaxies.

K. Lakhchaura, F. Mernier, N. Werner

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 (%CONTENT%gt;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.

Publisher URL: http://arxiv.org/abs/1812.00121

DOI: arXiv:1812.00121v2

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.