Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-19T04:46:29.015Z Has data issue: false hasContentIssue false
  • English
  • Français

Some Recent Results from UV Observations

Published online by Cambridge University Press:  18 September 2017

M. J. Seaton
M. J. Seaton*
Affiliation:
Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

UV observations with IUE have led to recognition of the importance of di-electronic recombination in PN, for the calculation of ionization equilibria and for production of the features C II λ1335 and C III λ2297.

The determination of C abundances is discussed. In high-excitation nebulae one must allow for absorption of C IV λ1549 by dust. It has been shown that C/O ≤ 0.5 for five PN with a silicate IR feature and that C/0 ≳ l for four with a SiC feature.

Dust opacities τD have been deduced from observed ratios (C IV λ1549)/(C III λ2297) and (C II λ1335)/(C I λ4267). The values obtained, τD ≃ 0.1, are consistent with the observed strength of thermal infra-red emission.

Earlier UV observations of PN were made by Pottasch et al. (1978) using ANS. Results obtained using IUE support neither their downward revisions of star temperatures nor their claim that a number of stars with TZ(He II) >> TZ (H I) are optically thick for H I.

From IUE observations it is concluded that the planetary κ 648 in M 15 has C/O = 2.4 and that its central star has a temperature of 30 000 κ and a luminosity of 1700 L⊙.

Type
Section I: Observations of Planetary Nebulae
Information
Symposium - International Astronomical Union , Volume 103: Planetary Nebulae , 1983 , pp. 129 - 139
Copyright
Copyright © Reidel 1983 

References

1. Adams, S, 1982, Mon. Not. R. astr. Soc., to be submitted.Google Scholar
2. Adams, S and Seaton, MJ, 1982a, Mon. Not. R. astr. Soc., to be submitted.Google Scholar
3. Adams, S and Seaton, MJ, 1982b, Mon. Not. R. astr. Soc., 200, 7P.Google Scholar
4. Aitken, DK and Roche, PF, 1982, Mon. Not. R. astr. Soc., 200, 217 Google Scholar
5. Aurière, M, Adams, S and Seaton, MJ, 1982, Mon. Not. R. astr. Soc., to be submitted.Google Scholar
6. Aurière, M and Cordoni, J-P, 1981, Astr. Astrophys., 100, 307.Google Scholar
7. Clavel, J, Flower, DR and Seaton, MJ, 1981, Mon. Not. R. astr. Soc., 197, 301.CrossRefGoogle Scholar
8. Flower, DR, 1980, Mon. Not. R. astr. Soc., 193, 511.Google Scholar
9. Flower, DR and Pen, CJ, 1981, Mon. Not. R. astr. Soc., 194, 13P.Google Scholar
10. Flower, DR, Penn, CJ and Seaton, MJ, 1982, Mon. Not. R. astr. Soc., in press.Google Scholar
11. Harrington, JP, Lutz, JH, Seaton, MJ and Stickland, DJ, 1980, Mon. Not. R. astr. Soc., 191, 13.Google Scholar
12. Harrington, JP, Lutz, JH and Seaton, MJ, 1981, Mon. Not. R. astr. Soc., 195, 21P.Google Scholar
13. Harrington, JP, Seaton, MJ, Adams, S and Lutz, JH, 1982, Mon. Not. R. astr. Soc., 199, 517.Google Scholar
14. Hawley, SA and Miller, JS, 1978, Astrophys. J. 220, 609.Google Scholar
15. Hummer, DG and Kunasz, PB, 1980, Astrophys. J., 236, 609 Google Scholar
16. Johnson, HM, Balick, B and Thompson, AR, 1979, Astrophys. J., 233, 919.CrossRefGoogle Scholar
17. Lambert, DL, 1978, Mon. Not. R. astr. Soc., 182, 249.Google Scholar
18. Moseley, H, 1980, Astrophys. J., 238, 892.Google Scholar
19. O'Dell, CR, Peimbert, M and Kinman, TD, 1964, Astrophys. J., 140, 119.CrossRefGoogle Scholar
20. Peimbert, M, 1973, Mém. Soc. Roy. Sci. Liège, 5, 307.Google Scholar
21. Pengelly, RM, 1963, , London (see also Seaton MJ, 1978, Planetary Nebulae (ed Terzian, Y.), p.131, Reidel).Google Scholar
22. Pottasch, SR, Wesselius, PR and van Duinen, RJ, 1978, Astr. Astrophys. 70, 629.Google Scholar
23. Pottasch, SR, Wesselius, PR, Wu, C-C, Fieten, H and van Duinen, RJ, 1978, Astron. Astrophys., 62, 95.Google Scholar
24. Sandage, A, 1970, Astrophys. J., 162, 841.Google Scholar
25. Storey, PJ, 1981, Mon. Not. R. astr. Soc., 195, 27P.CrossRefGoogle Scholar
26. Torres-Peimbert, S and Peimbert, M, 1977, Rev. Mex. Astron. y. Astrophys. 2, 181.Google Scholar