Dust in Clusters of Galaxies

TL;DR

This review discusses the complex presence and behavior of dust in galaxy clusters' intracluster medium, highlighting observational challenges, potential sources, and mechanisms affecting dust survival.

Contribution

It provides a comprehensive overview of observational and theoretical insights into dust in the ICM, emphasizing dust transport, survival mechanisms, and the implications for galaxy cluster studies.

Findings

Dust exists in the ICM despite harsh conditions.

Dust is primarily transported from galaxies into the ICM.

Survival of dust depends on shielding and environmental factors.

Abstract

The presence of dust in the intracluster medium (ICM) has been a long-standing problem that is still awaiting elucidation. Direct observational diagnostics are rather challenging (though not impossible) either because of a sparse distribution of dust in the intracluster space that makes extinction measurements difficult or because of a low surface brightness of infrared emission from dust. Complex indirect approaches are currently available that can overcome uncertainties and provide a reasonable understanding of the basic regulations of the physical state of dust in the ICM. Contrary to the common opinion that the hot ICM does not allow dust to survive and manifest, many sparse observational data either directly point out that dust exists in the intracluster space or its presence is consistent with the data. Highly divergent data in direct evidence and highly uncertain indirect indicators are often connected either with dust fragility in a hot environment, the possible compactness of spatial (clumpy) dust distribution in the ICM, or dynamical features of dust transport. The source of dust is obviously connected with galaxies, and it turns out that in most cases, dust is carried from galaxies into the ICM while being thermally and dynamically shielded against the hostile influence of high-energy ions. In this review, we briefly discuss related issues from observational and theoretical points of view, including the transport of dust into the ICM, and the associated destructive and protective mechanisms and their characteristic time scales.