__________ can be used to determine the galaxy's mass if the galaxy is reasonably close, so that the Doppler shift of the galaxy disk material can be measured at several distances from the galaxy's center relative to the center.
A)The Hubble constant
B)A galaxy's color
C)A galaxy's rotation curve
D)A galaxy's diameter
E)The velocity dispersion method

Question

Quizplus · Accepted Answer

A galaxy's rotation curve can be used to determine the galaxy's mass if the galaxy is reasonably close, so that the Doppler shift of the galaxy disk material can be measured at several distances from the galaxy's center relative to the center. By plotting the rotation speed against the distance from the center, the mass of the galaxy can be inferred from the amount of gravitational pull needed to maintain the observed rotation curve.

__________ Can Be Used to Determine the Galaxy's Mass If