The Small Wide Angle Tail NGC4874 in the Center of Coma Cluster

Abstract

NGC4874, one of the two dominant galaxies of the Coma cluster, is associated with a radio source of the Wide Angle Tail (WAT) type (Fig. 1), on a very small angular scale (Feretti and Giovannini 1985). The total linear extent, from the core to each tail edge, is ∼7 kpc (H_o= 100 km s^-1 Mpc^-1), and the radio structure is all contained within the optical boundary of the galaxy (Fig. 2). The total power of the radio source at 1.5 GHz is Log P_1.5=23.06 W/Hz; the core is very weak: S₅=0.9 mJy, which corresponds to a power Log P₅=20.76 W/Hz. This value is lower than that expected on the basis of the correlation P_core - P_tot found for radio galaxies (Feretti et al. 1984); however, it is still in agreement with this correlation, due to its large dispersion.