  We study the single-impurity Anderson model out of equilibrium under the
influence of a bias voltage $\phi$ and a magnetic field $B$. We investigate the
interplay between the shift ($\omega_B$) of the Kondo peak in the spin-resolved
density of states (DOS) and the one ($\phi_B$) of the conductance anomaly. In
agreement with experiments and previous theoretical calculations we find that,
while the latter displays a rather linear behavior with an almost constant
slope as a function of $B$ down to the Kondo scale, the DOS shift first
features a slower increase reaching the same behavior as $\phi_B$ only for $|g|
\mu_B B \gg k_B T_K$.
  Our auxiliary master equation approach yields highly accurate nonequilibrium
results for the DOS and for the conductance all the way from within the Kondo
up to the charge fluctuation regime, showing excellent agreement with a
recently introduced scheme based on a combination of numerical renormalization
group with time-dependent density matrix renormalization group.

Strongly Correlated Electrons;Mesoscale and Nanoscale Physics