We investigate the properties of long tidal tails using the largest to date sample of 461 merging galaxies with log(M_/M{sun})>=9.5 within 0.2=<z=20kpc. The high formation rate of straight tidal tails needs to be understood as the projection of curved tidal tails accounts for only a small fraction of the straight tails. We identify 165 tidal dwarf galaxies (TDGs), yielding a TDG production rate of 0.36 per merger. Combined with a galaxy merger fraction and a TDG survival rate from the literature, we estimate that ~5 per cent of local dwarf galaxies (DGs) are of tidal origin, suggesting the tidal formation is not an important formation channel for the DGs. About half of TDGs are located at the tip of their host tails. These TDGs have stellar masses in the range of 7.5=<log(M/M{sun})=<9.5 and appear compact with half-light radii following the M*-R_e relation of low-mass elliptical galaxies. However, their surface brightness profiles are generally flatter than those of local disc galaxies. Only 10 out of 165 TDGs have effective radii larger than 1.5kpc and would qualify as unusually bright ultradiffuse galaxies.

Cone search capability for table J/MNRAS/499/3399/table1 (The properties and measured tail parameters of our 461 LTTGs)

Cone search capability for table J/MNRAS/499/3399/table2 (The parameters of 165 TDGs identified from 126 merging galaxies with long tidal tails)