FAST MOTIONS OF GALAXIES IN THE COMA I CLOUD: A CASE OF DARK ATTRACTOR?

We note that nearby galaxies having high negative peculiar velocities are distributed over the sky very inhomogeneously. A part of this anisotropy is caused by the Local Velocity Anomaly, i.e., by the bulk motion of nearby galaxies away from the Local Void. However, half of the fast-flying objects reside within a small region [R.A. = 11.(h)5-13.(h)0, decl. = +20 degrees-40 degrees] known as the Coma I cloud. According to Makarov & Karachentsev, this complex contains 8 groups, 5 triplets, 10 pairs, and 83 single galaxies with a total mass of 4.7 x 10(13) M(circle dot). We use 122 galaxies in the Coma I region with known distances and radial velocities V(LG) < 3000 km s(-1) to draw the Hubble relation for them. The Hubble diagram shows a Z-shaped effect of infall with an amplitude of +200 km s(-1) on the nearby side and -700 km s(-1) on the back side. This phenomenon can be understood as the galaxy infall toward a dark attractor with a mass of similar to 2 x 10(14) M(circle dot) situated at a distance of 15 Mpc from us. The existence of a large void between the Coma and Virgo clusters also probably affects the Hubble flow around the Coma I.