Journal of the Korean earth science society (한국지구과학회지)

The Korean Earth Science Society (한국지구과학회)
권호 표지
DOI QR코드

DOI QR Code

Photoionization Models for Planetary Nebulae: Comparison of Predictions by NEBULA and CLOUDY

  • Lee, Seong-Jae (School of Science Education (Astronomy), Chungbuk National University) ;
  • Hyung, Siek (School of Science Education (Astronomy), Chungbuk National University)
  • Published : 2008.09.30
Download PDF
⟨ Previous Next ⟩

Abstract

The Galactic planetary nebulae emit many strong recombination and forbidden lines. By analyzing such lines, the physical condition of the planetary nebulae has been inferred using the strategically important diagnostic line ratios. In order to fully understand the physical condition of a planetary nebula and to derive its chemical abundances, the photoionization model codes, e.g., CLOUDY and NEBULA, were employed for an analysis of gaseous nebular spectra. For the well-studied, relatively simple planetary nebula NGC 7026, theoretical investigation was done with about the same input parameters in models. The predictions made by both codes seem to be in good accord. However, the predicted physical conditions, such as electron temperature and density, are slightly different. Especially, the electron temperatures are predicted to be higher in CLOUDY, which may cause a problem in chemical abundance determination. Our analysis shows that the main discordance may occur due to the diffuse radiation.

Keywords

References

  1. Aller, L.H., 1984, Physics of thermal gaseous nebulae. Reidel Publisher Company, Netherland, 350 p
  2. Ferland, G.J., 1997, Hazy I, a brief introduction to Cloudy 90 introduction and commands. Department of Physics and Astronomy, University of Kentucky, Lexington, 157 p
  3. Hubeny, I., 1988, a computer program for calculating non-LTE model stellar atmospheres. Computer Physics Community, 52, 103-130 https://doi.org/10.1016/0010-4655(88)90177-4
  4. Hyung, S., 1994, Density contrast shell models for the planetary nebula IC 2165. The Astrophysical Journal Supplement Series, 90, 119-148 https://doi.org/10.1086/191860
  5. Hyung, S. and Aller, L.H., 1998, The optical spectrum of the planetary nebula NGC 2440. Publications of the Astronomical Society of the Pacific, 111, 466-479
  6. Hyung, S., Aller, L.H., and Feibelman, W.A., 1994, The spectrum of the planetary nebula IC 418. Publications of the Astronomical Society of the Pacific, 106, 745-755 https://doi.org/10.1086/133438
  7. Hyung, S. and Feibelman, W.A., 2004, Optical and IUE spectra of the planetary nebula NGC 7026. The Astrophysical Journal, 614, 745-756 https://doi.org/10.1086/423660
  8. Kim, H. and Hyung, S., 2008, Chemical abundances of the symbiotic nova AG Pegasi. Journal of the Korean Astronomical Society, 41, 23-37 https://doi.org/10.5303/JKAS.2008.41.2.023
  9. Osterbrock, D.E., 1989, Astrophysics of gaseous nebulae and active galactic nuclei. University Science Books, Sausalito, California
  10. Osterbrock, D.E., 1989, Astrophysics of gaseous nebulae and active galactic nuclei. University Science Books, Sausalito, California
  11. Sabbadin, F., Turatti, M., Cappellaro, E., Benetti, S., and Ragazzoni, R., 2004, The 3-D ionization structure and evolution of NGC 7009 (Saturn Nebula). Astronomy and Astrophysics, 416, 955-981 https://doi.org/10.1051/0004-6361:20031729
  12. Workshop on Model Nebulae, 1986, edited by D. Pequignot (University of Paris), 1-108
  13. Zanstra, H., 1931, Publication of Dominion Astrophysics Observatory, 4, 209-272

Cited by

  1. Patterns of Astronomical Seeing at KSA SEM Observatory vol.30, pp.4, 2009, https://doi.org/10.5467/JKESS.2009.30.4.485
  2. 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
  3. High-resolution spectra of the planetary nebula NGC 6803 vol.549, pp.1432-0746, 2013, https://doi.org/10.1051/0004-6361/201219263
  4. Spectroscopic Study of the Symbiotic Star CI Cyg vol.35, pp.5, 2014, https://doi.org/10.5467/JKESS.2014.35.5.313
  5. Expansion velocities of the planetary nebula NGC 7009—the high dispersion spectra line profiles vol.352, pp.1, 2014, https://doi.org/10.1007/s10509-014-1893-z