Hostname: page-component-848d4c4894-nmvwc Total loading time: 0 Render date: 2024-07-03T13:59:12.460Z Has data issue: false hasContentIssue false

Variable X-ray Absorption in NGC 4151

Published online by Cambridge University Press:  07 August 2017

R. S. Warwick
Affiliation:
X-ray Astronomy Group, University of Leicester, Leicester LE1 7RH, United Kingdom
T. Yaqoob
Affiliation:
X-ray Astronomy Group, University of Leicester, Leicester LE1 7RH, United Kingdom
K. A. Pounds
Affiliation:
X-ray Astronomy Group, University of Leicester, Leicester LE1 7RH, United Kingdom

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The medium energy X-ray spectrum of the Seyfert galaxy NGC 4151 is characterised by a hard power-law continuum, a variable low-energy cut-off and iron line and edge features. Holt et al. (1980) found the spectral form below 4 keV to be incompatible with absorption in a uniform screen of cold gas and interpreted the apparent soft X-ray excess in terms of a partial covering model. However, recent observations point to a somewhat different description of the X-ray absorbing medium present in the nucleus of this galaxy.

Type
Part 3: X-rays and the Central Source
Copyright
Copyright © Kluwer 1989 

References

Clavel, J. et al., 1987, Astrophys. J. 321, 251 CrossRefGoogle Scholar
Ferland, G. & Rees, M., 1988, Astrophys. J., in press Google Scholar
Halpern, J., 1984, Astrophys. J. 281, 90 CrossRefGoogle Scholar
Holt, S.S. et al., 1980, Astrophys. J. 241, L13 CrossRefGoogle Scholar
Perola, G.C. et al., 1986, Astrophys. J. 306, 508 CrossRefGoogle Scholar
Pounds, K.A. et al., 1986, Mon. Not. R. astr. Soc. 218, 685 CrossRefGoogle Scholar
Yaqoob, T. Warwick, R.S. & Pounds, K.A., 1988, Mon. Not. R. astr. Soc., in press.Google Scholar