Proper radius containing half of the stellar mass, R_{0.5 stellar}, as a function of the stellar mass, M_stellar, of simulated stellar objects at redshift z = 0. Blue bins are DMC and red dots are DMF stellar objects. The stellar masses and the total half-mass radii of simulated TDGs by Fouquet et al. (2012) are shown as black crosses. A few DMC stellar objects can also be found in the regions of DMF stellar objects. The properties of these DMC stellar objects are studied in Fig. 11. The dashed vertical and horizontal lines indicate the initial baryonic matter mass of a particle (1.26 × 10⁶ M_⊙) and the smallest fiducial cell size (48 pc) of the Illustris-1 run, respectively. Subhalos with a stellar half-mass radius below the cell resolution are not shown in the plots. The yellow star shows the position of NGC 1052-DF2 with M_stellar = 2 × 10⁸ M_⊙ and a 3D deprojected half-light radius of 2.7 kpc (van Dokkum et al. 2018a).