What morphology is predicted for the resulting galaxy after the Milky Way and Andromeda merge?

A much larger, featureless elliptical galaxy

The predicted future of the Milky Way involves a massive gravitational interaction with the Andromeda galaxy (M31) in approximately 4.5 billion years. Although individual stars will largely pass by one another, the collision of their vast interstellar gas clouds will trigger an immense, short-lived burst of widespread star formation. Once this violent activity subsides and the merger process settles gravitationally, the resulting combined galaxy is expected to lose the defining rotational structure of spirals. The final outcome of such a major merger between two large spirals is typically the formation of a significantly larger, quiescent, and morphologically featureless elliptical galaxy, representing the transformation from an actively forming spiral to an aged elliptical state.