  We investigate the combined influence of quenched randomness and dissipation
on a quantum critical point with O(N) order-parameter symmetry. Utilizing a
strong-disorder renormalization group, we determine the critical behavior in
one space dimension exactly. For superohmic dissipation, we find a
Kosterlitz-Thouless type transition with conventional (power-law) dynamical
scaling. The dynamical critical exponent depends on the spectral density of the
dissipative baths. We also discuss the Griffiths singularities, and we
determine observables.
