I limiti del sole. Per una ricostruzione di Pacuvio, Antiopa fr. VIII, 12-14 R.3 (fr. VI, 12-14 D’Anna; fr. 7 Schierl)

The HST view of the FR I / FR II dichotomy ⋆

In order to explore how the FR I / FR II dichotomy is related to the nuclear properties of radio galaxies, we studied a complete sample of 26 nearby FR II radio galaxies using Hubble Space Telescope (HST) images and compared them with a sample of FR I previously analyzed. FR I nuclei lie in the radio-optical luminosity plane along a tight linear correlation, which argues for a common synchrotro...

Couverture FR

Spectral energy distributions of FR I nuclei and the FR I / BL Lac unifying model

We consider archival ROSAT and Hubble Space Telescope (HST) observations of five FR I radio galaxies and isolate their nuclear emission from that of the host galaxy. This enable us to determine the Spectral Energy Distributions (SED) of their nuclei spanning from the radio to the X–ray band. They cannot be described as single power–laws but require the presence of an emission peak located betwe...

The dividing line between FR I and FR II radio–galaxies

In the radio – host galaxy optical luminosity plane FR I and FR II radio–galaxies are clearly divided. Since the optical luminosity of an elliptical galaxy is an indication of the mass of its central black hole, we propose that the FR I–FR II dividing luminosity is a function of the mass of the black hole powering the active nucleus. Furthermore, as the radio power gives an estimate of the tota...

Jet/environment Interactions of Fr-i and Fr-ii Radio Galaxies

We present the results of new XMM observations of FR-I and FR-II radio galaxies that show the importance of jet/environment interactions for both radiosource structure and the properties of the surrounding gas. The FR-I observations reveal that the distribution of hot gas determines the radio-lobe morphology, and provide evidence that the subsonic expansion of the lobes heats the surrounding ga...