2025MNRAS.541.3445N

Our aim is to evaluate the maximum attainable energies of electrons accelerated by means of the magnetocentrifugal mechanism. We examine how the range of maximum possible energies, as well as the primary limiting factors, vary with black hole mass. Additionally, we analyse the dependence of the maximum relativistic factor on the initial distance from the black hole and its spin factor in the range 0.1-0.2. We model the acceleration of electrons on rotating magnetic field lines and apply several constraining mechanisms: the inverse Compton scattering, curvature radiation, and the breakdown of the bead-on-the-wire approximation. As a result, the maximum Lorentz factors for electron acceleration vary with the type of black hole. For stellar mass black holes, electrons can be accelerated up to the Lorentz factors $1.3 \times 10^{3} - 1.3 \times 10^{4}$ with only co-rotation constraint affecting the maximum relativistic factor. In intermediate-mass black holes, the Lorentz factors are in the interval $1.3 \times 10^4 - 1.1 \times 10^{5}$. For the supermassive black holes the Lorentz factors range from $7 \times 10^{4}$ to $1.7 \times 10^{5}$, while the ultramassive black hole located at the centre of Abell 1201 can accelerate electrons up to $10^{6}$ with both the co-rotation and Inverse Compton in Thomson regime determining the final Lorentz factor for the last three categories.