Faint extended elliptically shaped ultra-diffuse galaxies and slightly brighter and more compact dwarf elliptical and lenticular stellar systems are common in galaxy clusters. Their poorly constrained evolutionary paths can be studied by identifying young ultra-diffuse galaxy and dwarf elliptical analogues populated with bright, massive stars. Using data mining we identified 11 such low-mass (2 × 10⁸ M_⊙ < M_★ < 2 × 10⁹ M_⊙) galaxies with large half-light radii (2.0 kpc < r_e < 5 kpc) and recently quenched star formation in the Coma and Abell 2147 galaxy clusters. All galaxies happen to have ram-pressure-stripped tails with signs of current or recent star formation. Deep spectroscopic observations revealed rotating stellar disks containing 70–95% dark matter by mass. A large fraction of the disk stars (10–60%) formed in intense star bursts 180–970 Myr ago, probably triggered by ram pressure. Observed global gradients of stellar age corroborate this scenario. Passive evolution in the next 10 Gyr will transform 9 of the 11 galaxies into ultra-diffuse galaxies. If we assume a constant rate of galaxy infall, 44 ± 16% of the most luminous present-day ultra-diffuse galaxies in Coma must have formed via ram-pressure stripping of disky progenitors.

微弱延伸的椭圆形超漫射星系和稍亮且更紧凑的矮椭圆和透镜状恒星系统在星系团中很常见。可以通过识别年轻的超漫射星系和矮椭圆类似物来研究它们受到限制的进化路径，这些类似物居住着明亮的大质量恒星。通过数据挖掘，我们确定了 11个_具有大半光半径（2.0 kpc <  r _e ）的低质量（2 × 10 ⁸  M⊙  <  M _★  < 2 × 10 ⁹ _{M⊙ ）星系}  < 5 kpc) 和最近在 Coma 和 Abell 2147 星系团中淬火的恒星形成。所有星系都碰巧有冲压压力剥离的尾巴，带有当前或近期恒星形成的迹象。深光谱观测显示旋转的星盘包含 70-95% 的暗物质（按质量计）。大部分盘状恒星（10-60%）在 180-970 Myr 前的强烈恒星爆发中形成，可能是由撞击压力触发的。观测到的全球恒星年龄梯度证实了这种情况。在接下来的 10 Gyr 中，被动演化会将 11 个星系中的 9 个转变为超漫射星系。如果我们假设一个恒定的星系下落率，44 ± 16% 的当今最明亮的超漫射星系必定是通过对盘状祖先的撞击压力剥离形成的。