Intracluster Stars and the Chemical Enrichment of the Intracluster Medium

摘要

We explore the contribution of intracluster stars (ICS) to the chemicalenrichment history of the intracluster medium (ICM). In contrast to scenariosin which all the metals originate in cluster galaxies and are then transportedinto the ICM, intracluster stars enrich the ICM in situ, thereby contributing100% of their supernovae ejecta directly into the ICM. Modeling the ICS as anancient, single burst stellar population with a normal initial mass function,we generate ICM iron abundances in the range of the observed values of severaltenths solar. Large observational and theoretical uncertainties preclude usfrom concluding that the intracluster stars are the primary contributor ofmetals to the ICM in general. However, for the two clusters in our sample, andone from the literature, for which all of the required observationalconstraints exist, we are able to reproduce between half and all of the ICMiron. Due to the ubiquity of intracluster stars in clusters and their directconnection with the ICM, we conclude that all models of the chemical enrichmenthistory and energy budget of the ICM should account for the impact of the ICS.