Model of Hydrogen Deficient Nebulae in H II Regions at High Temperature

Belay S. Goshu^1,2, Derck P. Smits²

¹Dire-Dawa University, Dire-Dawa, Ethiopia.
²Department of Mathematics, Astronomy and Computing Science, UNISA, Pretoria, South Africa.

DOI: 10.4236/msce.2015.38004                

Abstract

In current photoionization models, determination of the ionization structure of the nebulae is a crucial part of the calculations for non-uniform hydrogen density. We have been tried to compute temperature fluctuations of electron and electron density by changing hydrogen density by scale factor of 10 at high temperature of blackbody. We have studied the ionization structure of hydrogen and helium by means of cloudy C13.01 codes. We find a reasonable close agreement of the computed value. Moreover, the ionization structure of oxygen at ionization stages of, O I - O IV, in gaseous nebulae are studied by changing non uniform hydrogen density with power law. Our simulation also shows that how the change of this density affect temperature fluctuations, electron density and ionization structures of oxygen, helium and hydrogen with and without grains. The result also shows the impact of the forbidden lines of [O III] and [O II] to cool down the temperature of electron.

Keywords

H II Regions, Planetary Nebulae, UV, Abundances, Interstellar Medium (ISM)

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Osterbrock, D.E. (1989) Astrophysics of Gaseous Nebulae and Active Galactic Nuclei. University Science Books, Mill Valley.
[2]	Tielens, A.G.G.M. (2005) The Physics and Chemistry of the Interstellar Medium. Cambridge University Press, New York.
[3]	Dopita, M.A. and Sutherland, R.S. (1999) Diffuse Matter in the Universe. The Australian National University, Canberra.
[4]	Smith, D. (2011) Model of Hydrogen Deficient Nebulae. African Skies/Cieux Africans, No. 16.
[5]	Stasinska, G. (2002) Abundance Determinations in H ii Regions and Planetary Nebulae.
[6]	Draine, B.T. (2011) Physics of the Interstellar and Intergalactic Medium. Princeton University Press, Princeton and Oxford.
[7]	Stassinska, G. (2002) The Electron Temperature in Ionized Nebulae.
[8]	Stasinska, G. and Schaerer, D. (1997) Combined Stellar Structure and Atmosphere Models for Massive Stars: IV. The Impact on the Ionization Structure of Single Star H II Regions. Astronomy & Astrophysics, 322, 615-623.
[9]	Ferland, G.J. (2013) Hazy: Introduction to Cloudy c13.1. Cloudy and Associates.
[10]	Gutierrez, L. and Beckman, J.E. (2008) The Physics of the H II Regions: The Photoionization Equilibrium in the H II Regions M51.
[11]	Mathis, J.S. (1984) Ionization Correction Factors for Low Excitation Gaseous Nebulae. The Astrophysical Journal, 291, 247-259. http://dx.doi.org/10.1086/163063
[12]	Rodriguez, M. and Rojas, J.G. (2010) Temperature Structure and Metallicity in H II Regions. The Astrophysical Journal, 708, 1551-1559.