Skip to main content
SpringerLink
Log in

Non-LTE effects in Mg I lines for various types of stars

  • Published:
Astronomy Reports Aims and scope Submit manuscript

Abstract

We have performed a detailed statistical-equilibrium analysis based on a 49-level model of the magnesium atom for the atmospheres of stars of various spectral types: T eff=4500–12000 K, logg=0.0–4.5, and [M/H]=0 to −3. In the atmospheres of stars with T eff>5500 K, deviations from LTE for Mg I are due to photoionization by ultraviolet radiation from the 3p level; i.e., neutral magnesium is in a state of “superionization.” When T eff<5500 K, the populations of the Mg I levels differ from their LTE values due to radiative processes in bound-bound transitions. We analyzed Mg I lines in the solar spectrum in order to empirically refine certain atomic parameters (the van der Waals broadening constant C 6 and cross sections for photoionization and collisional interactions with hydrogen atoms) and the magnesium abundance in the solar atmosphere. We studied non-LTE effects for five Mg I lines for a wide range of stellar parameters. In the case of dwarfs and subdwarfs, the magnitude of non-LTE corrections to magnesium abundances does not exceed 0.1 dex for the λλ 4571, 4703, 5528, and 5711 Å lines but can be as large as ±0.2 dex for the λλ 3829–3838, 5172, and 5183 Å lines. The non-LTE corrections for giants and supergiants do not exceed 0.15 dex for the λλ 4571 and 5711 Å lines but can reach ±0.20 dex and even more for the λλ 4703, 5528, 3829–3838, 5172, and 5183 Å lines.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. R. E. Luck and H. E. Bond, Astrophys. J. 292, 559 (1985).

    Article  ADS  Google Scholar 

  2. R. C. Peterson, Astrophys. J. 244, 989 (1981).

    ADS  Google Scholar 

  3. R. G. Gratton and S. Ortolani, Astron. Astrophys. 137, 6 (1984).

    ADS  Google Scholar 

  4. R. G. Gratton and C. Sneden, Astron. Astrophys. 178, 179 (1987).

    ADS  Google Scholar 

  5. P. Magain, Astron. Astrophys. 209, 211 (1989).

    ADS  Google Scholar 

  6. B. Edvardson, J. Andersen, B. Gustafsson, et al., Astron. Astrophys. 275, 101 (1993).

    ADS  Google Scholar 

  7. K. Fuhrmann, Astron. Astrophys. 338, 161 (1998).

    ADS  Google Scholar 

  8. P. E. Nissen and W. J. Schuster, Astron. Astrophys. 326, 751 (1997).

    ADS  Google Scholar 

  9. L. I. Mashonkina, N. N. Shimanskaya, and N. A. Sakhibullin, Astron. Zh. 73, 212 (1996) [Astron. Rep. 40, 187 (1996)].

    Google Scholar 

  10. Ya. V. Pavlenko, Effects of Deviation from LTE in the Atmospheres of M Giants [in Russian] (Valgus, Tallin, 1984).

    Google Scholar 

  11. Ya. V. Pavlenko, Astrofizika 28(1), 163 (1988).

    ADS  MathSciNet  Google Scholar 

  12. Ya. V. Pavlenko, Astrofizika 29(3), 520 (1988).

    ADS  MathSciNet  Google Scholar 

  13. R. G. Athay and R. C. Canfield, Astrophys. J. 156, 695 (1969).

    Article  ADS  Google Scholar 

  14. M. Lemke and H. Holweger, Astron. Astrophys. 173, 375 (1987).

    ADS  Google Scholar 

  15. E. Chang, E. Avrett, P. Mauas, et al., Astrophys. J. Lett. 379, L79 (1991).

    Article  ADS  Google Scholar 

  16. D. Hoang-Binh, Astron. Astrophys. 241, L13 (1991).

    ADS  Google Scholar 

  17. E. H. Avrett, E. S. Chang, and R. Loeser, IAU Symp. No. 154: Infrared Solar Physics (Kluwer, Dordrecht, 1992), p. 3.

    Google Scholar 

  18. M. Carlsson, R. J. Rutten, and N. G. Shchukina, Astron. Astrophys. 253, 567 (1992).

    ADS  Google Scholar 

  19. P. J. Mauas, E. H. Avrett, and R. Loeser, Astrophys. J. 330, 1008 (1988).

    Article  ADS  Google Scholar 

  20. G. Zhao, K. Butler, and T. Gehren, Astron. Astrophys. 333, 219 (1998).

    ADS  Google Scholar 

  21. R. L. Kurucz, CD-ROM No. 13 (1994).

  22. C. Moore, Atomic Energy Levels, Natl. Bur. Stand. Circ. (U. S.) 467, Vol. 1 (1949).

    Google Scholar 

  23. L. A. Vainshtein, I. I. Sobel’man, and E. A. Yukov, Excitation of Atoms and Broadening of Spectral Lines (Nauka, Moscow, 1979; Springer, Berlin, 1981).

    Google Scholar 

  24. H. van Regemorter, Astrophys. J. 136, 906 (1962).

    ADS  Google Scholar 

  25. D. Hofsaess, At. Data Nucl. Data Tables 24, 285 (1979).

    Article  ADS  Google Scholar 

  26. W. Steenbock and H. Holweger, Astron. Astrophys. 130, 319 (1984).

    ADS  Google Scholar 

  27. R. L. Kurucz, SYNTHE Spectrum Synthesis Programs and Line Data, CD-ROM, No. 18 (1994).

  28. S. E. Nersisyan, A. V. Shavrina, and A. A. Yaremchuk, Astrofizika 30(2), 247 (1989).

    ADS  Google Scholar 

  29. R. L. Kurucz, SAO Special Report, No. 309, 1 (1970).

  30. E. Anders and N. Grevesse, Geochim. Cosmochim. Acta 53(1), 197 (1989).

    Article  ADS  Google Scholar 

  31. N. A. Sakhibullin, Tr. Kazan. Gor. Astron. Obs. 48, 9 (1983).

    ADS  Google Scholar 

  32. I. Hubeny and T. Lanz, Astron. Astrophys. 262, 501 (1992).

    ADS  Google Scholar 

  33. A. A. Radtsig and B. M. Smirnov, Reference Data on Atoms, Molecules, and Ions (Springer, Berlin, 1985; Énergoatomizdat, Moscow, 1986).

    Google Scholar 

  34. H. R. Griem, Spectral Line Broadening by Plasmas (Academic, New York, 1974; Mir, Moscow, 1978).

    Google Scholar 

  35. C. Cowley, Observatory 91, 139 (1971).

    ADS  Google Scholar 

  36. A. Unsöld, Physik der Sternatmospheren, 2nd ed. (Springer, Berlin, 1955).

    Google Scholar 

  37. B. Warner, Z. Astrophys. 69, 161 (1968).

    ADS  Google Scholar 

  38. R. L. Kurucz, I. Furenlid, J. Brault, and L. Testerman, in Solar Atlas from 296 to 1300 nm (Nat. Solar Obs. Sunspot, New Mexico, 1984).

    Google Scholar 

  39. H. Holweger and E. A. Müller, Sol. Phys. 39, 19 (1974).

    Article  ADS  Google Scholar 

  40. P. Maltby, E. H. Avrett, M. Carlsson, et al., Astrophys. J. 306, 284 (1986).

    Article  ADS  Google Scholar 

  41. M. J. Seaton, C. J. Zeippen, J. A. Tully, et al., Rev. Mex. Astron. Astrofis. 23, 19 (1992).

    ADS  Google Scholar 

  42. W. Fullerton and Ch. R. Cowley, Astrophys. J. 165, 643 (1971).

    Article  ADS  Google Scholar 

  43. D. L. Lambert and B. Warner, Mon. Not. R. Astron. Soc. 140, 197 (1968).

    ADS  Google Scholar 

  44. D. L. Lambert and R. E. Luck, Mon. Not. R. Astron. Soc. 183, 79 (1978).

    ADS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Kazan State University, ul. Lenina 416, Kazan, 420111, Russia

    N. N. Shimanskaya, L. I. Mashonkina & N. A. Sakhibullin

Authors
  1. N. N. Shimanskaya
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. L. I. Mashonkina
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. N. A. Sakhibullin
    View author publications

    You can also search for this author in PubMed Google Scholar

Additional information

__________

Translated from Astronomicheski\(\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\smile}$}}{l} \) Zhurnal, Vol. 77, No. 8, 2000, pp. 599–618.

Original Russian Text Copyright © 2000 by Shimanskaya, Mashonkina, Sakhibullin.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Shimanskaya, N.N., Mashonkina, L.I. & Sakhibullin, N.A. Non-LTE effects in Mg I lines for various types of stars. Astron. Rep. 44, 530–547 (2000). https://doi.org/10.1134/1.1306354

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1134/1.1306354

Keywords

Search

Navigation