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Collisional ring galaxies (CRGs) are formed through off-center collisionsbetween a target galaxy and an intruder dwarf galaxy. We study the massdistribution and kinematics of the CRGs by tuning the bulge-to-disk mass ratio($B/D$) for the progenitor; i.e., the target galaxy. We find that the lifetimeof the ring correlates with the initial impact velocity vertical to the diskplane (i.e., $v_{z0}$). Three orbits for the collisional galaxy pair, on whichclear and asymmetric rings form after collisions, are selected to perform the\textit{N}-body simulations at different values of $B/D$ for the progenitor. Itis found that the ring structures are the strongest for the CRGs with smallvalues of $B/D$. The S\'{e}rsic index, $n$, of the central remnant in thetarget galaxy becomes larger after collision. Moreover, the S\'{e}rsic index ofa central remnant strongly correlates with the initial value of $B/D$ for theprogenitor. A bulge-less progenitor results in a late-type object in the centerof the ring galaxy, whereas a bulge-dominated progenitor leads to an early-typecentral remnant. Progenitors with $B/D\in [0.1,~0.3]$ (i.e., minor bulges)leave central remnants with $n\approx 4$. These results provide a possibleexplanation for the formation of a recently observed CRG with an early-typecentral nucleus, SDSS J1634+2049. In addition, we find that the radial andazimuthal velocity profiles for a ring galaxy are more sensitive to the $B/D$than the initial relative velocity of the progenitor.

Ring Galaxies Through Off-center Minor Collisions by Tuning Bulge-to-disk Mass Ratio of Progenitors