Abstract
OBSERVATIONS of the Seyfert galaxy NGC4151 by Ariel V, OSOI VII and UCSD (refs 1–3 respectively) have demonstrated that it has a relatively flat X-ray spectrum up to photon energies greater than 100 keV. The X-ray luminosity of this object is of the order of 4 × 1043 erg s−1 if a distance of 20 Mpc is assumed, and exceeds the integrated luminosity at all the other observed greater wavelengths. Long-term observations4 by Ariel V indicate that the X-ray emission may originate from a compact object with dimensions less than 8 × 1015 cm, presumably the nucleus of the Galaxy. Here we present the preliminary results of a positive measurement in the low energy γ-ray region of the spectrum, which are in good agreement with the X-ray data and confirm the intense high energy luminosity of the object.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Ives, J. C., Sanford, P. W. & Penston, M. V. Astrophys. J. Lett. 207, L159–L162 (1976).
Baity, W. A., Jones, T. W., Wheaton, Wm. A. & Peterson, L. E. Astrophys. J. Lett. 199, L5–L8 (1975).
Paciesas, W. S., Mushotzky, R. F. & Pelling, R. M. Mon. Not. R. astr. Soc. 178, 23P–25P (1977).
Elvis, M. Mon. Not. R. astr. Soc. 177, 7P–12P (1976).
Maccagni, D., Paizis, C., Perotti, F., Stiglitz, R., Villa, G., Bailey, P., Dean, A. J. & Ramsden, D. Proc. 9th Eslab Symp. Froscati 185–193 (1974).
Maccagni, D. et al. 14th Int. Cosmic Ray Conf. Munich 9, 3135–3140 (1975).
Gursky, H., Kellog, E. M., Leong, C., Tananbaum, H. & Giacconi, R. Astrophys. J. Lett. 165, L43–L48 (1971).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
DI COCCO, G., BOELLA, G., PEROTTI, F. et al. Low energy γ-ray observation of NGC4151. Nature 270, 319–320 (1977). https://doi.org/10.1038/270319a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/270319a0
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.