Dependence of the diffuse X-ray luminosities of virialized systems on the masses of their central objects

Abstract

Based on the available observational data on the diffuse X-ray emission from hot gas in virialized systems (the central regions of clusters of galaxies or the coronas of spherical galaxies) and the masses of the central objects in these systems (the central galaxies in clusters or massive compact objects—supermassive black holes—in the galactic nuclei), we show that the X-ray luminosity is proportional to the square of the mass of the central object. This is consistent with the dependence obtained earlier between X-ray luminosities of systems and the square of their optical luminosities (i.e., the luminosity of stars in these systems). The existence of such dependences for virialized systems on various scales may provide evidence that they are all formed by a single mechanism, such as hierarchical gravitational clustering. Although the times to achieve hydrostatic equilibrium between the gaseous and stellar components in systems on various scales differ, the relation between certain internal parameters of these systems may remain the same. This enables us to estimate certain parameters of virialized systems in terms of others, in particular, to estimate the masses of their central objects based on the diffuse X-ray luminosity of their coronas.