HOT EVOLVED OBJECTS IN DIFFERENT PARENT GALAXIES: THE STELLAR WINDS OF THREE PLANETARY NEBULA NUCLEI IN THE LARGE MAGELLANIC CLOUD

摘要

Three planetary nebulae in the Large Magellanic Cloud (LMC) were observed with the Faint Object Spectrograph on board the Hubble Space Telescope. Their central stars display P Cygni-like features in the ultraviolet. We modeled these profiles to derive the stellar wind velocities. The wind velocities of the LMC planetary nebula nuclei (PNNs) are comparable to those of some Galactic counterparts, but other Galactic objects of similar temperatures exist with higher wind velocities. One object, LMC-SMP 61, has a Wolf-Rayet (WR) type central star. For this nucleus we derived a wind velocity of - 1600 km s~(-1) and an upper limit to the mass-loss rate of M ≤ 7 x 10~(-7) solar mass yr~(-1) from the He and C lines. The observed continuum emission in the UV and optical range is modeled with a combination of stellar and nebular contributions, yielding independent determinations of stellar and nebular quantities. The sample is numerically too limited for a significant comparison between LMC and Galactic PNN populations, but represents the first exploration of mass-loss properties of evolved stellar objects beyond the Milky Way.