2004/09/29 by S. A. H. Müller, S. A. H. Mueller, M. Haas +5 · 24 citations
Physics and Astronomy · #Accretion (finance) #Active galactic nucleus #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Galaxy #Luminosity #Luminous infrared galaxy #Quasar #Radio Astronomy Observations and Technology #Radio galaxy #astro-ph
paper · pdf · doi:10.1051/0004-6361:200400067
published in Astronomy and Astrophysics 426(2), L29-L32 (EDP Sciences) · 4 pages 3 figures Letter accepted by A&A
arxiv created 2004/09/29 · openalex publication_date 2004/10/11 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We compare three 3CR samples of 11 FR 1 galaxies, 17 FR 2 galaxies and 18 lobe-dominated quasars contained in the ISO Data Archive. In contrast to the powerful FR 2 galaxies with edge-brightened lobes, the low radio power FR 1 galaxies in our sample do not exhibit any high MIR or FIR dust luminosity, which is typical for a buried, intrinsically more luminous AGN. This consolidates the fact already inferred from optical studies that their AGNs have only a relatively low luminosity. Also the FR 1 galaxies show a high FIR/MIR luminosity ratio, compared to quasars, suggesting that their FIR luminosity is substantially powered by the interstellar radiation field (ISRF) of the giant elliptical hosts. Finally, we discuss the FR 1 – FR 2 morphological dichotomy. FR 1 galaxies do not have more interstellar matter (ISM) than FR 2s as traced – on the large scale – by the cool FIR emitting dust and – in the nuclear region – by the warm MIR emitting dust. Due to the lack of central gas we suggest that the black holes of our FR 1 galaxies are fed at a lower accretion rate than those of the FR 2 galaxies.