Evidence for Relativistic Outflows in Narrow-line Seyfert 1 Galaxies

We report the observation of features near 1 keV in the ASCA spectra from three ``Narrow Line Seyfert 1'' (NLS1) galaxies. We interpret these as oxygen absorption in a highly relativistic outflow. If interpreted as absorption edges, the implied velocities are 0.2--0.3 c, near the limit predicted by ``line-locking'' radiative acceleration. If instead interpreted as broad absorption lines, the implied velocities are ~ 0.57 c, interestingly near the velocity of particles in the last stable orbit around a Kerr black hole, although a physical interpretation of this is not obvious. Interpretation in the context of a relativistic wind is supported by the fact that narrow-line Seyfert 1 galaxies share many optical emission-line and broad band properties with broad absorption line quasars. Many of these objects show strong or extreme Fe II and weak [O III] emission, have red continuum spectra and relatively strong infrared emission, and both classes are predominately radio quiet.