AGNs, X-ray background and the possible candidates for great attractor

In the five last years, different structures (density excess ∼1) have been proposed as the direct cause of our infall toward the direction of Hydra—Centaurus with a velocity of ∼500 km s−1. The direct effect of the mentioned matter accumulations on the X-ray background (XRB) can be estimated as a function of the geometry of the structures and of the cosmological evolution of the sources emitting in the X-ray band (2–10 keV) for different universes (Ω0≤1). If the XRB comes mostly from AGNs with low luminosity (L X <1043 erg s−1 and, therefore, they will have a weak cosmological evolution) and we consider the difference between the intensities coming from both hemispheres (that oriented toward the direction of our motion and the opposite one) obtained by means of different satellites, we can conclude that some candidates are highly unlikely.