1995A&A...296..359K

The dynamics of the Abell cluster 98 (A 98) and its two subclusters, A 98S and A 98N, distinguished in the galaxy and the X-ray surface brightness distributions, have been discussed. A 98S and A 98N, separated by 8.93arcmin, are moving with the relative radial velocity of 455km/s and are being merged. We have used the radial and the circular orbit models for two point masses of A 98S and A 98N estimated from the virial theorem and have derived the inclination angles of the orbital planes to the plane of sky. In the projection on the sky A 98S and A 98N lay at the position angle of 351deg, measured from the N- toward the E-S-W- direction, which is close to those of the optical major axis and of radio structure of radio galaxy 4C+20.04A (0043+2011A). The comparison of the thermal intracluster/intergalactic (ICM/IGM) gas pressure with the nonthermal (minimum) one indicates that radio lobes are confined by thermal pressure. However, the structure of radio jets is influenced by the hot (ICM/IGM) gas disturbed by the merger of subclusters.