Radiative Acceleration of Relativistic Jets from Accretion Disks Around Black Holes

Abstract

Matter falling onto black holes, also called accretion disks, emits intense high-energy radiation. Accretion disks during hard to hard intermediate spectral states also emit bipolar outflows. Radiation drag was supposed to impose the upper limit on the terminal speed. It was later shown that a radiation field around an advective accretion disk imposes no upper limit on speed, about a few hundred of Schwarzschild radius from the disk surface. We study radiatively driven electron-proton and electron-positron jets, for geometrically thick and slim transonic disks by using numerical simulation. We show that pair-dominated jets can reach ultra-relativistic speeds by radiation driving. We also discuss at what limits radiative acceleration may fail. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.