Formation of S0 galaxies through mergers

Abstract

Context. Lenticular (S0) galaxies are known to derive from spiral galaxies. The fact that S0s nearly obey the Tully-Fisher relation (TFR) at z ~ 0 (as spirals have done in the last ~9 Gyr) is considered an argument against their major-merger origin because equal mergers of two disc galaxies produce remnants that are outliers of the TFR.