Abstract
Following the first detection of X-ray emission from the Seyfert galaxy NGC41511, later observations2–4 have demonstrated that the X-ray spectrum up to 100 keV may be described by a power law having a differential spectral index 1<α<1.6 with a turnover at low energies caused by photoelectric absorption. Recently the results of an observation of this galaxy in the energy range 25–190 keV (ref. 5) have shown it to have a very hard spectrum with α≅0.9. Here more detailed results of the original observation of NGC4151 (ref. 6) using the MISO telescope are presented.
Similar content being viewed by others
References
Gursky, H., Kellogg, E. M., Leong, C., Tananbaum, H. & Giacconi, R. Astrophys. J. Lett. 165, L43 ( 1971).
Baity, W. A., Jones, T. W., Wheaton, Wm. A. & Peterson, L. E. Astrophys. J. Lett. 199, L5 (1975).
Ives, J. C., Sandford, P. W. & Penston, M. V. Astrophys. J. Lett. 207, L159 (1976).
Paciesas, W. S., Mushotzky, R. F. & Pelling, R. M. Mon. Not. R. astr. Soc. 178, 23P (1977).
Auriemma, G. et al. Astrophys. J. Lett. 221, L7 (1978).
Di Cocco, G. et al. Nature 270, 319 (1977).
Baker, R. E. et al. Nucl. Instrum. Meth. 158, 595 (1979).
Dolan, J. F. Astrophys. Space Sci. 17, 472 (1972).
Barr, P., White, N. E., Sanford, P. W. & Ives, J. C. Mon. Not. R. astr. Soc. 181, 43P (1977).
Mushotzky, R. F., Holt, S. S. & Serlemitsos, P. J. Astrophys. J. Lett. 225, L115 (1978).
Schonfelder, V. Nature 274, 344 (1978).
Schonfelder, V. Announcement of Kyoto, 16th ICRC (1979).
Bignami, G. F., Fichtel, C. E., Hartman, R. C. & Thompson, D. J. preprint (1979).
Elvis, M. Mon. Not. R. astr. Soc. 177, 7P (1976).
Meegan, C. A. & Haymes, R. C. preprint (1979).
Zanrosso, E. M., Long, J. L., Zych, A. D., Gibbons, D. & White, R. S. Proc. 16th ICRC, Kyoto, og 4–3 (1979).
Bergeron, J. & Salpeter, E. E. Astrophys. Lett. 9, 121 (1971).
Bergeron, J. & Salpeter, E. E. Astr. Astrophys. 22, 385 (1973).
Grindlay, J. E. Astrophys. J. 199, 49 (1975).
Pinkau, K. Proc. 16th ICRC, Kyoto, og4–16 (1979).
Fabian, A. C., Maccagni, D., Rees, M. J. & Stoeger, W. R. Nature 260, 683 (1976).
Lightman, A. P., Giacconi, R. & Tananbaum, H. Astrophys. J. 224, 375 (1978).
Maraschi, L., Perola, G. C., Reina, C. & Treves, A. Astrophys. J. (in the press).
Pacini, F. & Salvati, M. Astrophys. J. Lett. 225, L99 (1978).
Leiter, D. & Kafatos, M. Proc. La Jolla Institute, UCSD-Workshop on Particle Acceleration Mechanisms on Astrophysics (1979).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Perotti, F., Ventura, A., Sechi, G. et al. Low energy γ-ray spectrum of NGC4151. Nature 282, 484–486 (1979). https://doi.org/10.1038/282484a0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/282484a0
- Springer Nature Limited
This article is cited by
-
Hard X-Ray/Soft Gamma-Ray Experiments and Missions: Overview and Prospects
Space Science Reviews (2017)
-
A long duration balloon-borne telescope for solar gamma-ray astronomy
Experimental Astronomy (1989)
-
The contribution from active galactic nuclei to the diffuse 1 MeV background
Astrophysics and Space Science (1987)
-
The baryon-symmetric domain cosmology and the cosmic X-ray background
Astrophysics and Space Science (1987)
-
The saturation of the cosmic diffuse ?-ray background by the Seyfert galaxy component
Astrophysics and Space Science (1984)