IAU Symposium Abstract S186-005T

Galaxy interactions in the Local Volume

I.D.Karachentsev, D.I.Makarov
Special Astrophysical Observatory, Russian Academy of Sciences

We consider a sample of 240 galaxies with V0< 500 km/s. At the present its completness is expected to be about 60%. Being almost distance limited, the sample (=Local Volume= VL) has the mean number density $\sim0.25 gal/Mpc3. According to Vorontsov-Velyaminov and Arp a fraction of interacting galaxies in the LV consists of 7%, but drops to 2% when confusions with isolated irregular galaxies are taken into account. A relative number of apparent mergers in the LV sample seems to be about 3%.
For objective description of interaction we use a quantitative approach, supplying each of the LV galaxy with a "tidal index"
TI = MAX{ Mi/Ri3} i=1,...N

expressed via masses and separations of the galaxy neighbours. We present a total list of the LV galaxies with indication of their "Main Disturbers" (MD). Based on these data we note such properties of the LV sample: