Deep Chandra and XMM–Newton X-ray observations of AWM 7 – I. Investigating X-ray surface brightness fluctuations

摘要: We investigate the levels of small-scale structure in surface brightness images core X-ray bright cool-core galaxy cluster AWM 7. After subtraction a model smooth emission, we find number approximately radial depressions which are not present simulated and seen both Chandra XMM–Newton data. The most strongly south have magnitude around 4 per cent brightness. see these features an energy band sensitive to density (0.6–5 keV) more pressure (3.5–7.5 keV). Histograms data, when compared realizations model, reveal stronger variations. use Δ-variance technique characterize fluctuations as function length scale. that spectrum 0.6–5 keV is flatter than expected for Kolmogorov index fluctuations. If characterized by power spectrum, on large scales it would −1.7, rather −3.7. implied three-dimensional (3D) standard deviation cent. 3D variations at Most longer scale contributed southern half cluster, where seen. northern sector about 2 per