What information about protogalactic gas clouds is contained in ...

[OSWALD]

What information about protogalactic gas clouds is contained in quasar absorption lines?
 
  What will be an ideal response?

Question 2

You are in an airplane, traveling relative to the ground at 500 km/hr. You throw a baseball toward the front of the plane at a speed of 50 km/hr. How fast would someone on the ground say the baseball is moving?
 
  A) 550 km/hr
  B) 50 km/hr
  C) 500 km/hr
  D) 450 km/hr.

[dpost18]

Answer to Question 1

Quasar absorption lines show the presence of massive clouds of neutral hydrogen between us and the quasar. The hydrogen absorption line is generally wider for higher redshifts, indicating that the most distant clouds are more massive than the older, closer clouds, which have, presumably, converted some of their gas to stars. The absorption lines of heavier elements are stronger, however, at lower redshift, suggesting that the older, closer galaxies have enriched their interstellar medium more than the more distant, younger objects.

Answer to Question 2

A

[OSWALD]

Thanks for the timely response, appreciate it

[xiazhe]

Gracias!