A long tidal filament was detected associated with NGC 4660. This appears to indicate a past gravitational interaction with another galaxy. The progenitor galaxy that may have produced the filament associated with NGC 4660 was a gas-rich spiral. Alternatively, the detection of tidal dwarf galaxies[6] (TDGs) which are “recycled” low-mass galaxies formed from
interactions or
mergers[8] suggest that the filament originated from a possible
satellite galaxy that got stripped during its closest approach in its orbit to NGC 4660. This would make the filament a tidal stream comparable to the stream associated with the
Sagittarius Dwarf Spheroidal Galaxy of the
Milky Way.[6]
^Binggeli, B.; Sandage, A.; Tammann, G. A. (1985-09-01). "Studies of the Virgo Cluster. II - A catalog of 2096 galaxies in the Virgo Cluster area". The Astronomical Journal. 90: 1681–1759.
Bibcode:
1985AJ.....90.1681B.
doi:
10.1086/113874.
ISSN0004-6256.