High resolution X-ray spectroscopy allows accurate determinations of the temperature
distribution of the intracluster medium (ICM) in the cores of galaxy clusters. For
the first time we detect O VII emission, emitted from material around 0.35 keV
(~4MK), in a stacked 1.2 Ms spectrum of objects with central temperatures below 1
keV. The ratio of the O VII to Fe XVII emission is 1/4 to 1/8 of the amount expected
if the material is cooling radiatively. Another interesting finding is that the
average nitrogen to oxygen abundance ratio is 4 times the Solar value, which has
implications for understanding intermediate mass stars in these objects.
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