A line of peculiar galaxies associated with the cD galaxy NGC4889 in the Coma cluster

The field around the straight line was inspected, along which the unusual concentration of peculiar galaxies was encountered in 1977. The same region was examined on the Palomar Sky Survey prints and on isodensity tracing of the central region of the Coma Cluster. Seven peculiar galaxies out of eleven within 10 min. from the center of the Coma Cluster are approximately on a straight line emerging to the southwest from the supergiant elliptical galaxy NGC 4889. Faint galaxies (V less than 18.5 mag) concentrate also within 0.6 min. from this line with high statistical significance. The statistical significance of this line formation of galaxies was tested by plotting the positions of all galaxies detected on deeply exposed plate. The field in the rectangle ABCD was divided into twenty one strips of 0.6 min. width parallel to the line XY, and numbers of galaxies falling in each strip were counted. Similar counting of galaxies was made for two other arbitrarily chosen rectangles A'B'C'D' and A''B''C''D''. The frequency distribution of count numbers for the rectangles A'B'C'D' and A''B''C''D'' was well fitted with Poisson distribution. After discussion, if the line formation of galaxies in the 5C catalog is physically real, it is some chain phenomenon without strong radio emission, although it is optically similar to the galaxy chain associated with radioactive ellipticals in the rich clusters of galaxies. It was noted that the peculiar galaxies on this line were bluer as they were closer to NGC 4889. (Iwakiri, K.)