A VLA 20 and 90 centimetre radio survey of distant A-bell clusters with central cD galaxies

Bagchi, Joydeep ; Kapahi, Vijay K. (1994) A VLA 20 and 90 centimetre radio survey of distant A-bell clusters with central cD galaxies Journal of Astrophysics and Astronomy, 15 (3). pp. 275-308. ISSN 0250-6335

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Official URL: http://www.ias.ac.in/jarch/jaa/15/275-308.pdf

Related URL: http://dx.doi.org/10.1007/BF02709306


A radio survey, using the Very Large Array at 20 and 90 cm λ has been carried out in the direction of 46 distant Abell clusters (0.1 ≲ z ≲ 0.3) dominated by a cD galaxy (clusters classified to be Bautz-Morgan I type). A radio source coincident with the cD galaxy was detected in 16 clusters. We find that the radio luminosity function of the cD galaxies at 20cm λ, and below the luminosity P1.4GHz ≲ 1024.5 W Hz-1, is similar to that of brightest ellipticals in less clustered environments. Above this luminosity, the cDs seem to have a higher probability of becoming radio sources. The effect of optical brightness on radio emission is shown to be the same for the two classes. No significantly large population of very-steep-spectrum sources with spectral index α >1.2 (flux density ∝ frequency) was found to be associated with cD galaxies. A significant negative correlation is found between the radio luminosity of the cD galaxy and the cooling-time of the intra cluster medium near the galaxy. We also present evidence that the probability of radio emission from first-ranked galaxies is dependent upon their location relative to the geometrical centres of clusters and thus related to the morphological class and the evolutionary state of the clusters. We argue that both these effects are primarily caused by the dynamical evolution of these distant clusters of galaxies.

Item Type:Article
Source:Copyright of this article belongs to Indian Academy of Sciences.
Keywords:Clusters of Galaxies; cD Galaxies; Radio Luminosity Function; Cooling Flows
ID Code:28827
Deposited On:20 Dec 2010 08:15
Last Modified:17 May 2016 11:50

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