The mass of a galaxy can be determined from its _______________ ...

[KimWrice]

The mass of a galaxy can be determined from its _______________ curve.
 
  Fill in the blank(s) with correct word

Question 2

Explain the difference between cosmic rays and electromagnetic radiation, and how cosmic particles are captured.
 
  What will be an ideal response?

[nmyers]

Answer to Question 1

rotation

Answer to Question 2

Unlike electromagnetic radiation, which is made up of photons, cosmic rays are subatomic particles such as electrons and protons traveling at nearly the speed of light, arriving from mostly unknown cosmic sources.

Almost no cosmic rays reach the ground, but some of them smash into gas atoms in Earth's upper atmosphere, and fragments of those atoms shower down to the ground. Huge detectors must be built to catch and count them. For example, detectors for some kinds of cosmic rays have been carried on balloons or launched into orbit, while others have been built deep underground where layers of rock filter out all but the most penetrating particles.

[KimWrice]

Wow, this really help

[nyrave]

Thanks for the timely response, appreciate it