Skip to main content
Log in

The ionizing radiation field in the galactic centre and the nature of LINERs

  • Published:
Astrophysics and Space Science Aims and scope Submit manuscript

Abstract

The Galactic centre contains a low-ionization nebula that has been previously interpreted as plasma photoionized by relatively cool O stars. We consider the possibility that this material is instead ionized by more energetic continua and described by a relatively low ionization parameter (ratio of ionizing photon to nucleon density). We find that the predicted spectrum is more sensitive to ionization parameter and cloud density than to details of the ionizing continuum shape. The Galactic centre spectrum can be generated by stars with a range of temperatures irradiating clouds with multiple components of differing densities. The present calculations also show that optical emission from many LINERs (low-ionization nuclear emission-line regions) can be generated by relatively hot, yet normal O stars embedded in gas clouds similarly characterized by a range of densities.

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

Access this article

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

Instant access to the full article PDF.

Similar content being viewed by others

References

  • DePoy, D. L.: 1992,Astroph. J. 398, 512.

    Google Scholar 

  • Eckart, A.,et al.: 1992,Nature 355, 526.

    Google Scholar 

  • Ferland, G. J.: 1991,OSU Internal Report 91-01, Ohio State Astronomy, Columbus.

    Google Scholar 

  • Ferland, G. J., and Netzer, H.: 1983,Astroph. J. 264, 105.

    Google Scholar 

  • Filippenko, A. V., and Halpern, J. P.: 1984,Astroph. J. 285, 458.

    Google Scholar 

  • Genzel, R., and Townes, C. H.: 1987,Annual Rev. Astron. Astroph. 25, 377.

    Google Scholar 

  • Heckman, T. M.: 1980,Astro. Astroph. 87, 152.

    Google Scholar 

  • Lacy, J. H., Townes, C. H., Geballe, T. R., and Hollenbach, D. J.: 1980,Astroph. J. 241, 132.

    Google Scholar 

  • Phillips, M. M., Jenkins, C. R., Dopita, M. A., Sadler, E. M., and Binette, L.: 1986,Astron. J. 91, 1062.

    Google Scholar 

  • Phinney, E. S.: 1989, in M. Morris (ed.),IAU Symposium 136, The Center of the Galaxy Kluwer, Dordrecht, p. 543.

    Google Scholar 

  • Serabyn, E., and Lacy, J. H.: 1985,Astroph. J. 293, 445.

    Google Scholar 

  • Terlevich, R., and Melnick, J.: 1985,Monthly Not. Roy. Astr. Soc. 213, 841.

    Google Scholar 

  • Terlevich, R., Tenorio-Tagle, G., Franco, J., and Melnick, J.: 1992,Monthly Not. Roy. Astr. Soc. 255, 713.

    Google Scholar 

  • Watson, M. G., Willingale, R., Grindlay, J. E., and Hertz, P.: 1981,Astroph. J. 250, 142.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Shields, J.C. The ionizing radiation field in the galactic centre and the nature of LINERs. Astrophys Space Sci 205, 13–18 (1993). https://doi.org/10.1007/BF00657951

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00657951

Keywords

Navigation