What structure can tidal forces from close encounters contribute to forming over many passes near cluster cores?

Answer

The smooth, featureless nature of many large ellipticals

Repeated gravitational encounters and stretching caused by massive neighbors help erode sharp features, contributing to the smooth appearance often seen in large ellipticals located in cluster cores.

What structure can tidal forces from close encounters contribute to forming over many passes near cluster cores?
galaxystructuretimegravitydark matter