What does it mean when an emission line of helium from a galaxy is shifted toward red?(1 point) Responses The galaxy contains a large percent of hydrogen. The galaxy contains a large percent of hydrogen. The galaxy contains a small percent of hydrogen. The galaxy contains a small percent of hydrogen. The galaxy is moving toward the viewer. The galaxy is moving toward the viewer. The galaxy is moving away from the viewer.
1 answer
When an emission line of helium from a galaxy is shifted toward red, it indicates that the galaxy is moving away from the viewer. This phenomenon is known as redshift, which occurs due to the Doppler effect, where the wavelengths of light are stretched as the source moves away. Therefore, the correct response is:
The galaxy is moving away from the viewer.
