Question

Centaurus A is a radio galaxy that has a visible galaxy at the center. This central elliptical galaxy of Centaurus A is encircled by a ring of gas and dust, different from most elliptical galaxies. The dust ring orbits about an axis that is perpendicular to the axis of rotation of the elliptical galaxy. What does this suggest about this central elliptical galaxy of Centaurus A?

a) It suggests that the elliptical galaxy of Centaurus A has a rapidly changing rotational axis.
b) It suggests that the elliptical galaxy of Centaurus A has a highly inclined rotational axis.
c) It suggests that the elliptical galaxy of Centaurus A has a magnetic field that affects the dust ring's orbit.
d) It suggests that the elliptical galaxy of Centaurus A has a consistent, stable rotational axis.

Answer 1

The perpendicular ring of gas and dust around the elliptical galaxy in Centaurus A implies that the galaxy has a highly inclined rotational axis, likely due to a past merger.

Step-by-step explanation:

The elliptical galaxy at the center of Centaurus A, characterized by its peculiar ring of gas and dust, provides evidence about the galaxy's history and configuration. Given that the dust ring orbits perpendicularly to the axis of rotation of the elliptical galaxy, this suggests that the central galaxy has undergone some monumental event, such as a collision or merger, with another galaxy that brought in different angular momentum, affecting its structure. The correct answer is: b) It suggests that the elliptical galaxy of Centaurus A has a highly inclined rotational axis. This likely arises from the galactic merger that has resulted in a ring of material with rotation at a different orientation to the original galaxy’s axis.