Author Question: Via the rotation curve method, we can estimate the mass of galaxies like M31 from a. Doppler ... (Read 36 times)

aabwk4 · **on:** Jul 27, 2018

Via the rotation curve method, we can estimate the mass of galaxies like M31 from

a. Doppler shifts of material at the edge of its disk and computing P = 2r/v.
b. the distances of the Doppler shift points from its center.
c. Doppler shifts of material at the edge of its disk and computing P = 2r/v and the distances of the Doppler shift points from its center.
d. It is impossible to estimate the mass of M31.

Question 2

A planetary nebula

a. produces an absorption spectrum.
b. produces an emission spectrum.
c. is contracting to form planets.
d. is contracting to form a star.
e. is the result of carbon detonation in a 1- star.