Hot, low-density gas can be detected in galactic clusters through ...

[karateprodigy]

Hot, low-density gas can be detected in galactic clusters through X-ray emission. The gas is important in understanding dark matter because ____.
 
  a. dark matter is responsible for heating the gas
 b. dark matter must make the cluster massive enough to hold on to the hot gas
 c. the gas may be the source of dark matter
 d. the gas is clumped in empty places between galaxies where there is more dark matter
  e. the gas is produced by dark matter

Question 2

Why aren't optical or radio telescopes used in particle astronomy, which studies cosmic waves and gravity waves?
 
  a. Cosmic and gravity waves are too dangerous to detect.
 b. Particle astronomy can only be studied in deep space.
 c. Cosmic and gravity waves are too large of particles for ground-based telescopes.
 d. Optical and radio telescopes can only detect electromagnetic radiation.
 e. Optical and radio telescopes are not technologically advanced enough to capture these particles.

[djpooyouma]

Answer to Question 1

b

Answer to Question 2

d

[karateprodigy]

Thanks for the timely response, appreciate it

[xiazhe]

Wow, this really help