Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-26T11:28:39.498Z Has data issue: false hasContentIssue false

Observations of AGN with the Extreme Ultraviolet Explorer

Published online by Cambridge University Press:  19 July 2016

Herman L. Marshall*
Affiliation:
Eureka Scientific, Inc. 2452 Delmer St, Suite 100 Oakland, CA 94602 Massachusetts Institute of Technology 70 Vasser St., 37-667a Cambridge, MA 02139

Abstract

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 first results from surveys performed in the extreme ultraviolet (EUV) will be described in the context of studies of active galaxies and BL Lac objects. About a dozen extra-galactic sources are known so far to emit sufficient EUV radiation that they are detectable even through the Galactic interstellar medium. These results are interpreted in the context of a model of EUV or soft X-ray excesses in the case of AGN. In the case of BL Lac objects, the detections indicate that the steep soft X-ray power law spectra continue into the EUV and that there is little intrinsic gas. Finally, there now exists EUV spectra from the Extreme Ultraviolet Explorer for one BL Lac, PKS 2155-304 and two AGN: Mk 478 and NGC 5548. The spectra show no significant spectral features; for AGN, it indicates that optically thin and emission line models may have a difficult time explaining the EUV and soft X-ray bumps.

Type
New Observations of AGN with Specific Instruments
Copyright
Copyright © Kluwer 1994 

References

Balucinska-Church, M., and Gondhalekar, P. 1992, in X-ray Emission from Active Galactic Nuclei and the Cosmic X-ray Background , ed. Brinkmann, W., and Trümper, J., (Garching: MPE), 1992, 224.Google Scholar
Fink, H. H., Thomas, H.-C., Brinkmann, W., Okayashu, R., and Hartner, G. 1992, in X-ray Emission from Active Galactic Nuclei and the Cosmic X-ray Background , ed. Brinkmann, W. and Trümper, J., (Garching: MPE), 1992, 202.Google Scholar
Fruscione, A., Bowyer, S., Konigl, A., Kahn, S. 1993, Ap. J. (Letters) , submitted.Google Scholar
Kaastra, J., et al. 1993, these proceedings.Google Scholar
Lockman, F.J., Jahoda, K., and McCammon, D., 1986, Ap. J. , 302, 432.CrossRefGoogle Scholar
Lockman, F.J. and Savage, B. 1993 Ap. J. Suppl. , submitted.Google Scholar
Malina, R.F., et al. 1994, Astron. J. , accepted.Google Scholar
Marshall, H. L. 1991, in EUV Astronomy , Malina, R. F. and Bowyer, C. S., eds., (New York: Pergammon), p. 228.Google Scholar
Marshall, H.L., Carone, T.E., and Fruscione, A. 1993, Ap. J. (Letters) , 414, L53.Google Scholar
Marshall, H.L., Carone, T.E., and Fruscione, A. 1994, Ap. J. , submitted.Google Scholar
Marshall, H.L., Carone, T.E., Shull, J.M., Malkan, M., Elvis, M., and Green, R.F. 1994, in preparation.Google Scholar
Pounds, K., et al. 1993, M.N.R.A.S. , 260, 77.Google Scholar
Remillard, R. 1991, MC-LASS catalog, unpublished.Google Scholar
Turner, T.J., Weaver, K.A., Mushotzky, R.F., Holt, S.S., and Madejski, G.M. 1991 Ap. J. , 381, 85.Google Scholar
Wilkes, B.J. and Elvis, M. 1987, Ap. J. , 323, 243.Google Scholar