Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-01-09
Astronomy and Astrophysics
Astrophysics
Accepted in A&A
Scientific paper
10.1051/0004-6361:20053799
We present results from Chandra observations of the 3C/FRI sample of low luminosity radio-galaxies. We detected a power-law nuclear component in 12 objects out of the 18 with available data. In 4 galaxies we detected nuclear X-ray absorption at a level of about N_H= (0.2-6)e22 cm-2. X-ray absorbed sources are associated with the presence of highly inclined dusty disks (or dust filaments projected onto the nuclei) seen in the HST images. This suggests the existence of a flattened X-ray absorber, but of much lower optical depth than in classical obscuring tori. We thus have an un-obstructed view toward most FR~I nuclei while absorption plays only a marginal role in the remaining objects. Three pieces of evidence support an interpretation for a jet origin for the X-ray cores: i) the presence of strong correlations between the nuclear luminosities in the radio, optical and X-ray bands, extending over 4 orders of magnitude and with a much smaller dispersion (about 0.3 dex) when compared to similar trends found for other classes of AGNs, pointing to a common origin for the emission in the three bands; ii) the close similarity of the broad-band spectral indices with the sub-class of BL Lac objects sharing the same range of extended radio-luminosity, in accord with the FRI/BL Lacs unified model; iii) the presence of a common luminosity evolution of spectral indices in both FRI and BL Lacs. The low luminosities of the X-ray nuclei, regardless of their origin, strengthens the interpretation of low efficiency accretion in low luminosity radio-galaxies.
Balmaverde Barbara
Capetti Alessandro
Grandi Paola
No associations
LandOfFree
The Chandra view of the 3C/FRI sample of low luminosity radio-galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The Chandra view of the 3C/FRI sample of low luminosity radio-galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Chandra view of the 3C/FRI sample of low luminosity radio-galaxies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-683502