The discovery of a recent merger in the Andromeda galaxy was first based on interpreting its anomalous age-velocity dispersion relation, as well as the fact that 2 billion years ago, star formation throughout Andromeda's disk was much more active than today.
The discovery of a recent merger in the Andromeda galaxy was first? based on interpreting its anomalous age-velocity dispersion .relation, as well as the fact that 2 billion years ago, star formation throughout Andromeda's disk was much more active than today.