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Astron. Astrophys. 348, 437-445 (1999)
X-ray observations of low-power FR I radio galaxies
E. Trussoni 1,
F. Vagnetti 2,
S. Massaglia 3,
L. Feretti 4,
P. Parma 4,
R. Morganti 4,
R. Fanti 4,5 and
P. Padovani * 2,6
1 Osservatorio Astronomico di Torino, Strada dell'Osservatorio 20, I-10025 Pino Torinese (TO), Italy
2 Dipartimento di Fisica, Università di Roma "Tor Vergata", Via della Ricerca Scientifica, I-00133 Roma, Italy
3 Dipartimento di Fisica Generale dell'Università, Via P. Giuria 1, I-10125 Torino, Italy
4 Istituto di Radioastronomia del CNR, Via Gobetti 101, I-40129 Bologna, Italy
5 Dipartimento di Fisica dell'Università, Via Irnerio 46, I-40126 Bologna, Italy
6 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
Received 12 March 1999 / Accepted 16 June 1999
Abstract
According to unified schemes for Active Galactic Nuclei, low-power, Fanaroff-Riley type I (FR I), radio galaxies are thought to be BL Lacs with their jets pointing at relatively large angles with respect to the line of sight. X-ray observations of FR I sources can test this scenario and constrain the presence of obscuring material around the nucleus. In this paper we discuss the X-ray properties of three FR I radio galaxies 3C 78, OH-342 and PKS 0620-52, observed with the BeppoSAX satellite in the 0.2-10 keV energy range. The narrow-field instruments on board BeppoSAX have detected extended thermal X-ray emission from a hot galactic corona (3C 78) and intracluster gas (OH-342 and PKS 0620-52). However, a detailed spectral analysis suggests that a non-thermal (likely nuclear) component can also significantly contribute to the total flux, especially in the case of 3C 78 and OH-342. This emission from the central region appears basically unabsorbed, in agreement with observations in other bands. The X-ray spectral luminosity of the nucleus of these three objects is correlated with the radio core luminosity, consistently with previous data on other FR I radio galaxies.
Key words: galaxies:
active 
galaxies: individual: 3C 78; OH-342;
PK0620-52
galaxies: nuclei
* Affiliated to the Astrophysics Division, Space Science Department, European Space Agency
Send offprint requests to: E. Trussoni (Torino)
Contents
- 1. Introduction
- 2. The sources
- 3. Observations and data analysis
- 4. Results
- 5. Discussion and conclusions
- Acknowledgements
- References
© European Southern Observatory (ESO) 1999
Online publication: July 26, 1999
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