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 $<1.6\times {10}^{-4}$, $<3.6\times {10}^{-4}$, $\le 7.8\times {10}^{-4}$, and $\le 7.4\times {10}^{-4}$ 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.