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Temperature Scale and Iron Abundances of Very Hot Central Stars of Planetary Nebulae

Published online by Cambridge University Press:  26 May 2016

Klaus Werner
Affiliation:
Institut für Astronomie und Astrophysik, Univ. Tübingen, Germany
Jochen L. Deetjen
Affiliation:
Institut für Astronomie und Astrophysik, Univ. Tübingen, Germany
Stefan Dreizler
Affiliation:
Institut für Astronomie und Astrophysik, Univ. Tübingen, Germany
Thomas Rauch
Affiliation:
Institut für Astronomie und Astrophysik, Univ. Tübingen, Germany
Jeff W. Kruk
Affiliation:
Department of Physics and Astronomy, JHU, Baltimore MD, U.S.A.

Abstract

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The determination of effective temperatures of very hot central stars (Teff > 70 000 K) by model atmosphere analyses of optical H and He line profiles is afflicted with considerable uncertainty, primarily due to the lack of neutral helium lines. Ionization balances of metals, accessible only with UV lines, allow more precise temperature estimates. The potential of iron lines is pointed out. At the same time iron and other metal abundances, hardly investigated until today, may be derived from UV spectra. We describe recent HST spectroscopy performed for this purpose.

A search for iron lines in FUV spectra of the hottest H-deficient central stars (PG1159-type, Teff >100000 K) taken with FUSE was unsuccessful. The derived deficiency is interpreted in terms of iron depletion due to n-capture nucleosynthesis in intershell matter, which is now exposed at the stellar surface as a consequence of a late He shell flash.

Type
Part IV: Central Stars and their Atmospheres
Copyright
Copyright © Astronomical Society of the Pacific 2003 

References

Asplund, M., Lambert, D.L., Kipper, T., et al. 1999, A&A, 343, 507 Google Scholar
Blöcker, T. & Schönberner, D. 1990, A&A 240, L11 Google Scholar
Busso, M., Gallino, R., Wasserburg, G.J. 1999, ARA&A, 37, 239 Google Scholar
Deetjen, J.L., Dreizler, S., Rauch, T., Werner, K. 1999, A&A, 348, 940 Google Scholar
Heap, S.R. 1975, ApJ 196, 195 CrossRefGoogle Scholar
Heap, S.R. 1983, in Planetary Nebulae, IAU Symp. 103, ed. Flower, D.R., Dordrecht, Reidel, p. 375 Google Scholar
Herwig, F. 2001, in Low Mass Wolf-Rayet Stars: Origin and Evolution, ed. Waters, R., Zijlstra, A., Blöcker, T., Ap&SS 275, 15 Google Scholar
Herwig, F., Blöcker, T., Langer, N., Driebe, T. 1999, A&A 349, L5 Google Scholar
Hoare, M.G., Drake, J.J., Werner, K., Dreizler, S. 1996, MNRAS 283, 830 Google Scholar
Kudritzki, R.P., Méndez, R.H., Puls, J., McCarthy, J.K. 1997, in Planetary Nebulae, IAU Symp. 180, ed. Habing, H.J., Lamers, H.J.G.L.M., Kluwer, p. 64 Google Scholar
Liebert, J.W. 1993, in Planetary Nebulae, IAU Symp. 155, ed. Weinberger, R., Acker, A., Kluwer, p. 443 Google Scholar
Méndez, R.H., Kudritzki, R.P., Herrero, A., et al. 1988, A&A 190, 113 Google Scholar
Méndez, R.H. 1991, in Evolution of Stars: The Photospheric Abundance Connection, IAU Symp. 145, ed. Michaud, G., Tutukov, A.V., Kluwer, p. 375 Google Scholar
Miksa, S., Deetjen, J.L., Dreizler, S., et al. 2001, in White Dwarfs, ed. Provencal, J.L., Shipman, H.L., MacDonald, J., Goodchild, S., ASP Conf. Series 226, 60 Google Scholar
Miksa, S., Deetjen, J.L., Dreizler, S., et al. 2002, A&A submitted Google Scholar
Napiwotzki, R. 1992, in Atmospheres of Early-Type Stars, ed. Heber, U., Jeffery, C.S., LNP 401, Springer, Berlin, p. 310 Google Scholar
Napiwotzki, R. 1999, A&A 350, 101 Google Scholar
Parthasarathy, M., Acker, A., Stenholm, B. 1998, A&A 329, L9 Google Scholar
Rauch, T., Dreizler, S., Wolff, B. 1998, A&A 338, 651 Google Scholar
Rauch, T., Heber, U., Werner, K. 2002, A&A 381, 1007 Google Scholar
Schönberner, D. 1983, ApJ 272, 708 Google Scholar
Schönberner, D. & Drilling, J.S. 1985, ApJ 290, L49 Google Scholar
Torres-Peimbert, S., Peimbert, M., Peña, M. 1990, A&A 233, 540 Google Scholar
Tweedy, R.W. & Napiwotzki, R. 1992, MNRAS 259, 315 Google Scholar
Werner, K. 1992, in Atmospheres of Early-Type Stars, ed. Heber, U., Jeffery, C.S., LNP401, Springer, Berlin, p. 273 Google Scholar
Werner, K. 1996, ApJ 457, L39 Google Scholar
Werner, K. 2001, in Low Mass Wolf-Rayet Stars: Origin and Evolution, ed. Waters, R., Zijlstra, A., Blöcker, T., Ap&SS 275, 27 Google Scholar
Werner, K., Dreizler, S. 1999, Journal of Comp. and Applied Math. 109, 65 Google Scholar