Space Science Reviews

, Volume 84, Issue 1–2, pp 95–103 | Cite as

Temperature Fluctuations, H II Region Abundances, and Primordial Helium

  • Gary Steigman
  • Sueli M. Viegas
  • Ruth Gruenwald


There is evidence for temperature fluctuations in Planetary Nebulae and in some Galactic H II regions. If such fluctuations occur in the low metallicity, extragalactic H II regions used to probe the primordial helium abundance, the derived 4He mass fraction, YP, could be systematically different from the true primordial value. Although this effect could be large, there are no data which allow us to estimate the size of the temperature fluctuations for the extragalactic H II regions. Therefore, we have explored this effect via Monte Carlo simulations of the data in which the abundances derived from a fiducial data set are modified by ΔT chosen from a distribution with 0 ≤ ΔT ≤ ΔTmax where ΔTmax is varied from 500 K to 4000 K.

Temperature Fluctuations H II Region Abundances Primordial Helium 


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  1. Brocklehurst, M.: 1972, MNRAS 157, 211.Google Scholar
  2. Clegg, R. E. S.: 1987, MNRAS 229, 31P.Google Scholar
  3. Cox, D. P., and Daltabuit, E.: 1971, ApJ 167, 257.Google Scholar
  4. Davidson, K., and Kinman, T. D.: 1985, ApJS 58, 321.Google Scholar
  5. Esteban, C., and Peimbert, M.: 1995, A&A 300, 78.Google Scholar
  6. Ferland, G. J.: 1986, ApJ 310, L67.Google Scholar
  7. González-Delgado, R. M., Pérez, E., Tenorio-Tagle, G., Vilchez, J. M., Terlevich, E., Terlevich, R., Telles, E., Rodriguez-Espinosa, J. M., Mas-Hesse, M., García-Vargas, M. L., Díaz, A. I., Cepa, J., and Castañeda, J.: 1994, ApJ 437, 239.Google Scholar
  8. Hata, N., Scherrer, R. J., Steigman, G., Thomas, D., Walker, T. P., Bludman, S., and Langacker, P.: 1995, Phys. Rev. Lett. 75, 3977.Google Scholar
  9. Izotov, Y. I., Thuan, T. X., and Lipovetsky, V. A.: 1994, ApJ 435, 647 (ITL).Google Scholar
  10. Izotov, Y. I., Thuan, T. X., and Lipovetsky, V. A.: 1997, ApJS 108, 1 (ITL).Google Scholar
  11. Kingdon, J., and Ferland, G. J.: 1995, ApJ 442, 714.Google Scholar
  12. Liu, X., and Danziger, J.: 1993, MNRAS 263, 256.Google Scholar
  13. Olive, K. A., Skillman, E., and Steigman, G.: 1997, ApJ 483, 788 (OSS).Google Scholar
  14. Olive, K. A., and Steigman, G.: 1995, ApJS 97, 49 (OS).Google Scholar
  15. Osterbrock, D. E. 1989, ‘Astrophysics of Gaseous Nebulae and Active Galactic Nuclei’, (Mill Valley, University Science Books)Google Scholar
  16. Pagel, B. E. J., Simonson, E. A., Terlevich, R. J., and Edmunds, M.: 1992, MNRAS 255, 325 (PSTE).Google Scholar
  17. Peimbert, M.: 1971, Bol. Obs. Tonantzintla y Tacubaya 6, 29.Google Scholar
  18. Peimbert, M.: 1995, in ‘The Analysis of Emission Lines’, ed. R. E. Williams and M. Livio (Cambridge; Cambridge Univ. Press), 165.Google Scholar
  19. Peimbert, M.: 1996, Rev. Mex. Astr. Astrofis., Serie de Conferencias 4, 55.Google Scholar
  20. Skillman, E., and Kennicutt, R. C.: 1993, ApJ 411, 655.Google Scholar
  21. Skillman, E., Terlevich, R. J., Kennicutt, R. C., Garnett, D. R., and Terlevich, E.: 1994, ApJ 431, 172.Google Scholar
  22. Steigman, G., Schramm, D. N., and Gunn, J.: 1977, Phys. Lett. B66, 202.Google Scholar
  23. Steigman, G., Viegas, S. M., and Gruenwald, R.: 1997, ApJ 490, In Press (Nov. 20, 1997) (SVG).Google Scholar
  24. Terlevich, E., Diaz, A. I., Terlevich, R., González-Delgado, R. M., Pérez, E., and García-Vargas, M. L.: 1996, MNRAS 279, 1219.Google Scholar
  25. Viegas, S. M., and Clegg, R.: 1994, MNRAS 271, 993.Google Scholar

Copyright information

© Kluwer Academic Publishers 1998

Authors and Affiliations

  • Gary Steigman
    • 1
  • Sueli M. Viegas
    • 2
  • Ruth Gruenwald
    • 2
  1. 1.Departments of Physics and AstronomyThe Ohio State UniversityColumbusUSA
  2. 2.Instituto Astronômico e GeofísicoUniversidade de São PauloSão PauloBRASIL

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