HUBBLE-SPACE-TELESCOPE OBSERVATIONS OF PLANETARY-NEBULAE IN THE MAGELLANIC CLOUDS - VI - CYCLE-4 AND CYCLE-5 ULTRAVIOLET SPECTROSCOPY USINGTHE FAINT OBJECT SPECTROGRAPH

The Faint Object Spectrograph on board the Hubble Space Telescope (HST ) is used to obtain spectra in the wavelength range lambda lambda 1150 -4800 of three planetary nebulae in the Small Magellanic Cloud and 10 planetary nebulae in the Large Magellanic Cloud. This sample extends t he sample of 12 objects previously observed with HST and reported in t he third paper of this series. Observed and dereddened emission-line f luxes are presented. Reddening estimates from the He II lambda 1640/la mbda 4686 flux ratio are generally up to 0.2 dex lower than the redden ing derived from the Balmer decrement. Nebular temperatures are estima ted from the N+ lambda lambda 2138, 2142/lambda lambda 6548, 6583 flux ratio. Nebular densities are calculated from the O IV] complex at lam bda 1400, the N IV] lambda lambda 1483, 1487 doublet, and the Si III] lambda lambda 1883, 1892 doublet. Densities calculated using the oxyge n lines are comparable to those determined from the optical lines. Den sities calculated from the nitrogen lines show a scatter of over 3 dex , which is relatively large compared to the optically derived densitie s. Three of the five densities derived from the silicon lines are grea ter than 10,000 cm(-3). The C+2/O+2, Si+2/C+2, and N+2/O+2 ionic abund ance ratios are calculated using the available ultraviolet emission fe atures. The C/O and N/O ratios are anticorrelated, which supports the premise that third dredge-up has taken place during the asymptotic gia nt branch phase. In contrast to the third paper in this series, type I classification does not imply the presence of Si mi emission. Three o bjects show P Cygni-like line profiles at C IV lambda lambda 1548, 155 1, indicative of stellar winds.