Astronomy and Astrophysics, volume 585A, 147-147 (2016/1-1)
The amazing diversity in the hot gas content of an X-ray unbiased massive galaxy clusters sample.
ANDREON S., SERRA A.L., MORETTI A. and TRINCHIERI G.
Abstract (from CDS):
We aim to determine the intrinsic variety, at a given mass, of the properties of the intracluster medium in clusters of galaxies. This requires a cluster sample selected independently of the intracluster medium content for which reliable masses and subsequent X-ray data can be obtained. We present one such sample, consisting of 34 galaxy clusters selected independently of their X-ray properties in the nearby (0.050<z<0.135) Universe and mostly with 14<logM500/M☉ ≲14.5, where masses are dynamically estimated. We collected the available X-ray observations from the archives and then observed the remaining clusters with the low-background Swift X-ray telescope, which is extremely useful for sampling a cluster population expected to have low surface brightness. We found that clusters display a large range (up to a factor 50) in X-ray luminosities within r500 at a given mass, whether or not the central emission (r<0.15r500) is excised, unveiling a wider cluster population than seen in Sunayev-Zeldovich surveys or inferred from the population seen in X-ray surveys. The measured dispersion is 0.5dex in LX at a given mass.
galaxies: clusters: intracluster medium - X-rays: galaxies: clusters - galaxies: clusters: general - methods: statistical