Present day mass function of Coma Ber and group-X with mass derived from PARSEC isochrone with an age of 800 Myr and 400 Myr, respectively. (a) MFs of Coma Ber (red line) and group-X (blue line). The mass function from Tang et al. (2018) for Coma Ber is shown in gray line. The slope, α, is fitted for MF from 0.25 M_☉ to 2.51 M_☉. (b) Surface number density mass functions of Coma Ber in different annuli on the X–Y plane. The slope, α, is fitted with the mass range as the black dashed lines showed. The binwidth is log(M/M_☉) = 0.2. The x-value of each dot represents the central value of each bin.