Ionized reflection is one of the possible mechanisms proposed to explain the small short-timescale variability of the MCG–6-30-15 Fe Kα line. In this contribution, we fit the Ross & Fabian ionized reflection models to the 325 ks XMM-Newton observation of MCG–6-30-15. It is found that the spectrum above 2.5 keV can be fitted with a combination of an ionized reflector from 5 r g and a neutral rep...

An edge-coloured graph G is rainbow connected if any two vertices are connected by a path whose edges have distinct colours. A graph G is called rainbow k-connected, if there is an edge-colouring of G with k colours such that G is rainbow-connected. In this talk we will study rainbow k-connected graphs with a minimum number of edges. For an integer n ≥ 3 and 1 ≤ k ≤ n− 1 let t(n, k) denote the ...