This topic contains a solution. Click here to go to the answer

Author Question: Why do we believe galaxy clusters are rich in dark matter? What will be an ideal ... (Read 67 times)

jayhills49

  • Hero Member
  • *****
  • Posts: 559
Why do we believe galaxy clusters are rich in dark matter?
 
  What will be an ideal response?

Question 2

Why is Cygnus X-1 considered such a good black hole candidate?
 
  What will be an ideal response?



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

zhanghao

  • Sr. Member
  • ****
  • Posts: 316
Answer to Question 1

Studies of the gravitational interaction of clusters reveal they have 10-100 times more mass than is visible.

Answer to Question 2

The massive visible star is pulled around by an invisible massive companion in a 5.6 day orbit. If the visible star is a giant of 30 solar masses, then the companion must be close to 10 solar masses, well over the 3 solar mass limit for black holes. Also, the matter pulled off the visible star is seen to be flowing toward the dark companion, where it generates much X-rays in the accretion disk.




jayhills49

  • Member
  • Posts: 559
Reply 2 on: Jul 27, 2018
Thanks for the timely response, appreciate it


debra928

  • Member
  • Posts: 342
Reply 3 on: Yesterday
Excellent

 

Did you know?

The use of salicylates dates back 2,500 years to Hippocrates's recommendation of willow bark (from which a salicylate is derived) as an aid to the pains of childbirth. However, overdosage of salicylates can harm body fluids, electrolytes, the CNS, the GI tract, the ears, the lungs, the blood, the liver, and the kidneys and cause coma or death.

Did you know?

Many medications that are used to treat infertility are injected subcutaneously. This is easy to do using the anterior abdomen as the site of injection but avoiding the area directly around the belly button.

Did you know?

Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.

Did you know?

The largest baby ever born weighed more than 23 pounds but died just 11 hours after his birth in 1879. The largest surviving baby was born in October 2009 in Sumatra, Indonesia, and weighed an astounding 19.2 pounds at birth.

Did you know?

Critical care patients are twice as likely to receive the wrong medication. Of these errors, 20% are life-threatening, and 42% require additional life-sustaining treatments.

For a complete list of videos, visit our video library