Very rapid time variations help establish the tiny size of many ...

[panfilo]

Very rapid time variations help establish the tiny size of many X-ray sources, showing they must be collapsed objects of some kind.
 
  Indicate whether the statement is true or false

Question 2

What can cause a galactic fountain?
 
  A) winds and jets from newly-formed protostars
  B) a supernova occurring in the halo
  C) multiple supernovae occurring together
  D) the combined effect of spiral density waves
  E) molecular clouds falling towards the galactic center

[aham8f]

Answer to Question 1

TRUE

Answer to Question 2

C

[panfilo]

Excellent

[jojobee318]

Gracias!