Electromagnetic two-body currents of one- and two- pion range

The nuclear electromagnetic two-body current operator is calculated up to next-to-next-to-leading order in chiral perturbation theory. A number of low-energy electronuclear observables including \textit{np} radiative capture cross section at neutron thermal energies, deuteron magnetic moment and isoscalr and isovector magnetic moments of $^{3}$H and $^{3}$He are calculated. The matrix elements are evaluated using nuclear wave functions obtained from realistic Hamiltonians involving the Argonne $v_{18}$ and CD Bonn two-nucleon and the Urbana IX three-nucleon interactions.