1. Long term monitoring of Seyfert Galaxies with BeppoSAX Wide Field Cameras.
- Author
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Dadina, M., Piro, L., Soffitta, P., and Muller, J. M.
- Subjects
- *
SEYFERT galaxies , *ARTIFICIAL satellites , *ASTRONOMICAL observations - Abstract
ABSTRACT We preset first results of the long term monitoring of Seyfert Galaxies with BeppoSAX Wide Field Cameras (WFCs). We have firstly examined the data of the Seyfert 1.5 NGC 4151, This object is known to be one of the brightest Seyferts ranging from few to about 15 mCrab in the 2 - 10 keV energy range. As of September 13, 1998, the sky region containing NGC 4151 has been observed by WFCs in secondary mode (i.e., when the narrow field instruments are performing prime observations) about 80 times. We report here the results of the analysis of 21 observations. The minimum flux at which the source was detected is ∼ 4 mCrab, In June of this year we found the source at ∼ 20 mCrab, the highest state ever recorded. The study of the light curve of the very faint and stable source Cas A gives a preliminary assessment of systematic errors of ∼20%. The preliminary results obtained, confirm that the WFCs are powerful tools for the study of bright AGN. [ABSTRACT FROM AUTHOR]
- Published
- 1999