A 2000 Kilometer per Second ``Pristine'' Post-asymptotic Giant Branch Wind in the Proto-planetary Nebula He 3-1475

Abstract

We analyze (archival) Space Telescope Imaging Spectrograph long-slit Hα spectra of the proto-planetary nebula He 3-1475. We find two remarkable blueshifted absorption features arising from the inner ~5×10¹⁶ cm of the nebula, revealing the presence of two different winds outflowing at high velocity from the central star. The kinematic age of these winds is only tens of years. We find that the fast wind is flowing with velocities in the range ~150-1200 km s^-1 whereas the ultrafast wind is moving much faster (up to 2300 km s^-1). The latter is highly collimated (length/width >~7) close to the central star (~10¹⁶ cm) along a direction different from previous mass ejection axes and shows a radially increasing velocity. We identify the ultrafast wind with a ``pristine'' post-asymptotic giant branch (post-AGB) outflow that has not been (strongly) altered by its interaction with the AGB envelope. We discuss the implications of the spatiokinematic structure of this wind for current theories of the formation and shaping of planetary nebulae.