Accretion Rates onto Massive Black Holes in Four Quiescent Elliptical Galaxies

Four quiescent elliptical galaxies were imaged with the NRAO VLA at 8.5 GHz. Within the context of canonical advection-dominated accretion flows (ADAFs), these VLA images plus published black hole masses constrain the accretion rates to be $ <1.6times10^{-4}$, $ <3.6times10^{-4}$, $le7.8times10^{-4}$, and $le7.4times10^{-4}$ of the Eddington rates. These ADAF accretion rates derived at 8.5 GHz have important implications for the levels of soft and hard X-rays expected from these quiescent galaxies.