A search for reflection features in the X-ray spectrum of NGC 4151.
Abstract
We report results from a contemporary observation of NGC 4151 from 4-120 keV by Ginga and the HEXE instrument aboard Kvant from 1987 November 21^st^ to 24^th^. This is the first spectrum of an AGN over this broad energy range since HEAO-1, but with higher sensitivities and higher energy resolution. No source variability was found during the observations in both the Ginga and the HEXE data. We found the source to be in a low state of emission in the X-ray range. The spectrum is well described by a single power law with an intensity of 1.44^+0.45^_-0.32_ X 10^-2^ photons/cm^2^ sec keV at 1 keV and an energy index α=0.37^+0.11^_-0.11_ over the entire energy range, plus absorption by a hydrogen column of 6.7 x 10^22^cm-^2^ and an iron emission line at 6.4 keV. The spectrum is fitted equally well by a model including some reflection from a layer of cold matter, but the reflected component is significantly smaller than would be expected if half the primary radiation would be reprocessed. We discuss the constraints our fits can place on the importance and magnitude of a reflected component and the influence of pairs on the non- thermal power-law emission from NGC 4151 in the observed low state.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- September 1991
- Bibcode:
- 1991A&A...249...25M
- Keywords:
-
- Active Galactic Nuclei;
- Astronomical Spectroscopy;
- Seyfert Galaxies;
- Wave Reflection;
- X Ray Spectroscopy;
- Active Galaxies;
- Satellite Observation;
- X Ray Astronomy;
- Astrophysics