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Entropy of the intracluster medium at high redshift

Biman B. Nath
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Abstract

Recent observations of entropy of intracluster medium (ICM) at high redshift are not consistent with a redshift independent entropy floor. In order to interpret these observations, we study models in which the entropy of ICM is enhanced at the epoch of cluster formation (z_f), which then passively evolves as a result of radiative cooling until the epoch of observation (z_o). We confirm that a z-independent entropy floor is incompatible with the observations. We find that models in which energy deposition into the ICM increases with redshift (scaling approximately as $\sim M_cl^0.6 (1+z_f)^2.2$) are consistent with observations of low and high redshift clusters. Possible sources of such non-gravitational heating are briefly discussed.

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Biman B. Nath. 2004-06-21. Entropy of the intracluster medium at high redshift. https://doi.org/10.1111/j.1365-2966.2004.08124.x

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