caa a22 4500 469077174 CHVBK 20180323132938.0 cr unu---uuuuu 170328e19920901xx s 000 0 eng 10.1007/BF02507856 doi (NATIONALLICENCE)springer-10.1007/BF02507856 High-energy spectral changes in three Seyfert galaxies observed with GINGA [Elektronische Daten] [F. Fiore, G. Perola, M. Matsuoka, L. Piro] Summary: We have analysed observations of the three Seyfert Galaxies IC4329A, MCG-6-30-15 and NGC 4051 extracted from the GINGA archive. The variations in the (4⋎18) keV spectrum of the three sources can be interpreted in the framework of a model with two components: a <<direct>> power law with constant spectral index (α=1.9⋎2.1), and the <<reflection bump>> predicted by Guilbert and Rees, and Lightman and White which is produced by reprocessing of the direct power law in optically thick matter in the surroundings of the central source. The differences found in the behaviour of the three sources would arise, in this scenario, from the different size of the <<reprocessing region>>. Società Italiana di Fisica, 1992 X-ray sources nationallicence X-ray binaries nationallicence Fiore F. Istituto Astronomico, Università di Roma «La Sapienza», Italia aut Perola G. Istituto Astronomico, Università di Roma «La Sapienza», Italia aut Matsuoka M. The Institute of Physical and Chemical Research, 351-01, Wako-shi, Saitama, Japan aut Piro L. Istituto di Astrofisica Spaziale, CNR, Via E. Fermi 21, 00044, Frascati, Italia aut Il Nuovo Cimento C Kluwer Academic Publishers 15/5(1992-09-01), 819-823 0390-5551 15:5<819 1992 15 11543 https://doi.org/10.1007/BF02507856 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02507856 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Fiore F. Istituto Astronomico, Università di Roma «La Sapienza», Italia aut NATIONALLICENCE 700 1- Perola G. Istituto Astronomico, Università di Roma «La Sapienza», Italia aut NATIONALLICENCE 700 1- Matsuoka M. The Institute of Physical and Chemical Research, 351-01, Wako-shi, Saitama, Japan aut NATIONALLICENCE 700 1- Piro L. Istituto di Astrofisica Spaziale, CNR, Via E. Fermi 21, 00044, Frascati, Italia aut NATIONALLICENCE 773 0- Il Nuovo Cimento C Kluwer Academic Publishers 15/5(1992-09-01), 819-823 0390-5551 15:5<819 1992 15 11543 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer