We present new BeppoSAX LEGS, MECS, and PDS observations of five lobe-dominated, broad-line active galactic nuclei selected from the 2 Jy sample of southern radio sources. These include three radio quasars and two broad-line radio galaxies. ROSAT PSPC data, available for all the objects, are also used to Letter constrain the spectral shape in the soft X-ray band. The collected data cover the 0.1-10 keV energy range, reaching 40 keV for one source. Detailed spectral fitting shows that all sources have a flat hard X-ray spectrum with energy index alpha(x) similar to 0.75 in the 2 - 10 keV energy range. This is a new result, which is at variance with the situation at lower energies where these sources exhibit steeper spectra. Spectral breaks similar to 0.5 at 1 - 2 keV characterize the overall X-ray spectra of our objects. The flat, high-energy slope is very similar to that displayed by flat-spectrum/core-dominated quasars, which suggests that the same emission mechanism (most likely inverse Compton) produces the hard X-ray spectra in both classes. Contrary to the optical evidence for some of our sources, no absorption above the Galactic value is found in our sample. Finally, a (weak) thermal component is also present at low energies in the two broad-line radio galaxies included in our study.

Morganti, R., Padovani, P., Siebert, J., Cimatti, A., Tadhunter, C., Vagnetti, F. (1999). BeppoSAX observations of 2 Jy lobe-dominated broad-line sources: the discovery of a hard X-ray component. In Nuclear Physics B - Proceedings Supplements (pp.435-438). AMSTERDAM : ELSEVIER SCIENCE BV.

BeppoSAX observations of 2 Jy lobe-dominated broad-line sources: the discovery of a hard X-ray component

VAGNETTI, FAUSTO
1999-01-01

Abstract

We present new BeppoSAX LEGS, MECS, and PDS observations of five lobe-dominated, broad-line active galactic nuclei selected from the 2 Jy sample of southern radio sources. These include three radio quasars and two broad-line radio galaxies. ROSAT PSPC data, available for all the objects, are also used to Letter constrain the spectral shape in the soft X-ray band. The collected data cover the 0.1-10 keV energy range, reaching 40 keV for one source. Detailed spectral fitting shows that all sources have a flat hard X-ray spectrum with energy index alpha(x) similar to 0.75 in the 2 - 10 keV energy range. This is a new result, which is at variance with the situation at lower energies where these sources exhibit steeper spectra. Spectral breaks similar to 0.5 at 1 - 2 keV characterize the overall X-ray spectra of our objects. The flat, high-energy slope is very similar to that displayed by flat-spectrum/core-dominated quasars, which suggests that the same emission mechanism (most likely inverse Compton) produces the hard X-ray spectra in both classes. Contrary to the optical evidence for some of our sources, no absorption above the Galactic value is found in our sample. Finally, a (weak) thermal component is also present at low energies in the two broad-line radio galaxies included in our study.
Symposium on the Active X-ray Sky
ROME, ITALY
OCT 21-24, 1996
Rilevanza internazionale
1999
Settore FIS/05 - ASTRONOMIA E ASTROFISICA
English
EXTRAGALACTIC RADIO-SOURCES; ACTIVE GALACTIC NUCLEI; COMPLETE SAMPLE; SPECTRA; QUASARS
Intervento a convegno
Morganti, R., Padovani, P., Siebert, J., Cimatti, A., Tadhunter, C., Vagnetti, F. (1999). BeppoSAX observations of 2 Jy lobe-dominated broad-line sources: the discovery of a hard X-ray component. In Nuclear Physics B - Proceedings Supplements (pp.435-438). AMSTERDAM : ELSEVIER SCIENCE BV.
Morganti, R; Padovani, P; Siebert, J; Cimatti, A; Tadhunter, C; Vagnetti, F
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/44730
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