Journal of The Korean Astronomical Society (천문학회지)

The Korean Astronomical Society (한국천문학회)
권호 표지
DOI QR코드

DOI QR Code

EXPANSION VELOCITY INVESTIGATION OF THE ELLIPTICAL PLANETARY NEBULA NGC 6803

  • Choi, Youn-Su (School of Science Education (Astronomy), Chungbuk National University) ;
  • Lee, Seong-Jae (School of Science Education (Astronomy), Chungbuk National University) ;
  • Hyung, Siek (School of Science Education (Astronomy), Chungbuk National University)
  • Published : 2008.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

Using the spectral data in the 3700 to $10050{\AA}$ wavelength range secured with the Hamilton Echelle Spectrograph (HES) at the Lick observatory, we have investigated the expansion velocities and the physical conditions of the elliptical planetary nebula NGC 6803. Various forbidden and permitted lines, e.g. HI, HeI, HeII, [OIII], [NII], [ArIII], and [SII], indicate complicated but systematic physical conditions variation: electron temperatures $T_{\varepsilon}\;{\sim}\;9000$ - 11000 K and electron number densities $N_{\varepsilon}\;{\sim}\;2000$ - $9000\;cm^{-3}$. The line profile analysis of these ions also indicates the systematic change or the acceleration of the expansion velocities in the range of 10 - $22\;km\;s^{-1}$. We show that the velocity gradient and physical condition found in various ions are closely related to the prolate ellipsoidal structure of NGC 6803. The expansion velocity and the ionic abundance of $O^{2+}$ were derived based on the OII and [OIII] lines. In spite of the discrepancy of ionic abundances derived by the two cases and their line profiles, the expansion velocities of them agree well. We find that the ratios of the red to blue line component of the HeII & OII lines are different from those of the [OIII] or other forbidden lines that indicates a possible involvement of emission of HeII & OII lines. This subtle difference and the different physical condition of the lines are likely to be caused by the elongated geometry and the latitude dependence of the emission zone.

Keywords

References

  1. Aller, L. H., 1956, Gaseous Nebulae (London: Chapman & Hall)
  2. Barlow, M. J., Hales, A. S., Storey, P. J., Liu, X.-W., Tsamis, Y. G., & Aderin, M. E., 2006, bHROS high spectral resolution observations of PN forbidden and recombination line profiles, IAU Symposium, 234, 367
  3. Castor, J. I., Lutz, J. H., & Seaton, M. J., 1981, Ultraviolet spectra of planetary nebulae. III - Mass loss from the central star of NGC 6543, MNRAS, 194, 547 https://doi.org/10.1093/mnras/194.3.547
  4. Clegg, R. E. S., Miller, S., Storey, P. J., & Kisielius, R., 1999, Recombination Line Intensities for Hydrogenic Ions: The fine-structure components of HI and HeII, A&A, 135, 359 https://doi.org/10.1051/aas:1999178
  5. Hyung, S., 1994, Density contrast shell models for the planetary nebula IC 2165, ApJS, 90, 119 https://doi.org/10.1086/191860
  6. Hyung, S. & Aller, L. H., 1998, The Optical Spectrum of the Planetary Nebula NGC 2440, PASP, 110, 466 https://doi.org/10.1086/316155
  7. Hyung, S., Aller, L. H., & Feibelman, W. A., 1993, The spectrum of the planetary nebula NGC 6567, PASP, 105, 1279 https://doi.org/10.1086/133308
  8. Hyung, S. & Feibelman, W. A., 2004, Optical and IUE Spectra of the Planetary Nebula NGC 7026, ApJ, 614, 745 https://doi.org/10.1086/423660
  9. Jacoby, G. H. & Ford, H. C., 1983, The hydrogendepleted planetary nebulae Abell 30 and Abell 78, ApJ, 266, 298 https://doi.org/10.1086/160779
  10. Lee, H. W. & Hyung S., 2000, Broad $H{\alpha}$ Wing Formation in the Planetary Nebula IC 4997, ApJ, 530, 49 https://doi.org/10.1086/312479
  11. Liu, X. W., Storey, P. J., Barlow, M. J., & Clegg, R. E. S., 1995, The rich OII recombination spectrum of the planetary nebula NGC 7009: new observations and atomic data, MNRAS, 272, 369-388 https://doi.org/10.1093/mnras/272.2.369
  12. Mellema, G., 1997, The formation of bipolar planetary nebulae, A&A, 321, 29
  13. Peimbert, M., 1967, Temperature Determinations of H II Regions, ApJ, 150, 825 https://doi.org/10.1086/149385
  14. Pequignot, D., Petitjean, P., & Boisson, C., 1991, Total and effective radiative recombination coefficients, A&A, 251, 680-688
  15. Sabbadin, F., Turatti, M., Cappellaro, E., Benetti, S., & Ragazzoni, R., 2004, The 3-D ionization structure and evolution of NGC 7009 (Saturn Nebula), A&A, 416, 955 https://doi.org/10.1051/0004-6361:20031729
  16. Sabbadin, F., Benetti, S., Cappellaro, E., Ragazzoni, R., & Turatto, M., 2005, The 3-D shaping of NGC 6741: A massive, fast-evolving Planetary Nebula at the recombination-reionization edge, A&A, 436, 549 https://doi.org/10.1051/0004-6361:20042447
  17. Sabbadin, F., Turatto, M., Ragazzoni, R., Cappellaro, E., & Benetti, S., 2006, The structure of planetary nebulae: theory vs. practice, A&A, 451, 937 https://doi.org/10.1051/0004-6361:20054554
  18. Storey, P. J., 1994, Recombination coefficients for OII lines at nebular temperatures and densities, A&A, 282, 999-1013
  19. Wesson, R., Liu, X. W., & Barlow, M. J., 2005, The abundance discrepancy - recombination line versus forbidden line abundances for a northern sample of galactic planetary nebulae, MNRAS, 362, 424-454 https://doi.org/10.1111/j.1365-2966.2005.09325.x
  20. Wilson, O. C., 1950, A Survey of Internal Motions in the Planetary Nebulae, ApJ, 111, 279 https://doi.org/10.1086/145264
  21. Zhang, Y., Liu, X.-W., Luo, S.-G., Pequignot, D., & Barlow, M. J., 2005, Integrated spectrum of the planetary nebula NGC 7027, A&A, 442, 249 https://doi.org/10.1051/0004-6361:20052869

Cited by

  1. Spectroscopic Study of the Planetary Nebula NGC 6210: Velocity Structure and Permitted Lines vol.30, pp.5, 2009, https://doi.org/10.5467/JKESS.2009.30.5.611
  2. HIGH-DISPERSION SPECTRUM OF THE HALO PLANETARY NEBULA DdDm 1 vol.705, pp.1, 2009, https://doi.org/10.1088/0004-637X/705/1/509
  3. High-resolution spectra of the planetary nebula NGC 6803 vol.549, 2013, https://doi.org/10.1051/0004-6361/201219263