NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-04-25 T00:56:58 PDT
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For refcode 2007MNRAS.379..260M:
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Copyright by Royal Astronomical Society. 2007MNRAS.379..260M The interplay between radio galaxies and cluster environment Manuela Magliocchetti and Marcus Brueggen Abstract. By combining the REFLEX and NORAS cluster data sets with the NVSS radio catalogue, we obtain a sample of 145, z < 0.3, X-ray-selected clusters brighter than 3 x 10^-12^ erg s^-1^ cm^-2^ that show a central radio emission above 3 mJy. For virial masses M_vir_ ~< 10^14.5^ M_sun_, 11 clusters out of 12 (corresponding to 92 per cent of the systems) are inhabited by a central radio source. This fraction decreases with higher masses as is proportional to M^-0.4^_vir_. If this decrease is a selection effect, it suggests that the majority of X-ray-selected clusters host in their centre a radio source brighter than ~10^20^ W Hz^-1^ sr^-1^. A division of the sample into clusters harbouring either point-like or an extended radio-loud active galactic nucleus (AGN) reveals that the steepening of the L_X_ -T relation for low-temperature clusters is strongly associated with the presence of central radio objects with extended jets and/or lobe structures. In the latter case, L_X_ is proportional to T^4^ while for point-like sources one recovers an approximately self-similar relation L_X_ is proportional to T^2.3^. Monte Carlo simulations show that the steepening of the L_X_ -T relation is not caused by clusters being underluminous in the X-ray band, but rather by overheating, most likely caused by the interplay between the extended radio structures and the intracluster medium. In the case of low-mass systems, we also find a tight correlation between radio luminosity and cluster temperature. The effects of the central radio source on the thermal state of a cluster become less important with increasing cluster mass. The presence of radio sources with extended structures (61, corresponding to ~42 per cent of the sample) is enhanced in X-ray luminous clusters with respect to 'field' radio-loud AGN. Furthermore, we find that the luminosity distribution of the cluster radio population differs from that of all radio sources, as there is a deficit of low-luminosity (L_R_ ~< 10^22^ W Hz^-1^ sr^-1^) objects, while the number of high-luminosity ones is boosted. The net effect on the radio luminosity function of radio galaxies associated with cluster centres is of a flattening at all luminosities L_R_ ~< 10^24^ W Hz^-1^ sr^-1^. Key words: galaxies: active, galaxies: clusters: general, galaxies: statistics, cosmology: observations, radio continuum: galaxies, X-rays: galaxies: clusters
Retrieve 278 NED objects in this reference.
Please click here for ADS abstract

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