A possible model of persistent X-ray-luminous gas around the giant elliptical galaxy M87

We have investigated, through spherically symmetric hydrodynamical simulati on, whether thermal conduction together with stellar activities (mass loss and Type Ia supernovae) can stabilize the X-ray-emitting gas near the cente r of elliptical galaxies. The configurations of the gas are divided into tw o distinct states, depending on the amount of intracluster gas surrounding the galaxy and the stellar mass-loss rate in the galaxy. One is a state of thermal balance between the radiative cooling and thermal conduction that c an persist for more than 10 Gyr. The gas reaches nearly hydrostatic equilib rium in the galactic potential, with the gas density declining as r(-1). Th e X-ray luminosity can be as bright as that observed in M87, depending on t he initial intracluster gas densities. Subsolar Fe abundance of the gas is expected. The other state results in a cooling catastrophe near the center on a timescale of 10(7)-10(8) yr owing to radiative cooling. This catastrop he arises when (1) the initial intracluster gas density is so low that the thermal energy in the intracluster gas is too low to carry enough energy in ward and (2) the stellar mass-loss rate or the initial intracluster gas den sity is so large that the timescale of cooling outweighs that of conduction .