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

Author Question: The mass of visible matter in a galaxy can be estimated by measuring its luminosity. When this is ... (Read 68 times)

ss2343

  • Hero Member
  • *****
  • Posts: 548
The mass of visible matter in a galaxy can be estimated by measuring its luminosity. When this is compared with the measured mass of the galaxy, astronomers find that ____.
 
  a. the measured mass is about ten times the estimated mass, due to the effects of the central black hole
  b. the measured mass is approximately equal to the estimated mass
 c. there is no clear relationship between the estimated and measured mass
 d. the measured mass is about ten times the estimated mass, due to the effects of dark matter
 e. the estimated mass is about ten times the measured mass, due to the effects of dark matter

Question 2

What technique often requires the use of a laser guide star?
 
  a. active optics
 b. photometry
 c. adaptive optics
 d. comparison spectrum
 e. representational color imaging



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

ErinKing

  • Sr. Member
  • ****
  • Posts: 362
Answer to Question 1

d

Answer to Question 2

c





 

Did you know?

Adolescents often feel clumsy during puberty because during this time of development, their hands and feet grow faster than their arms and legs do. The body is therefore out of proportion. One out of five adolescents actually experiences growing pains during this period.

Did you know?

Ether was used widely for surgeries but became less popular because of its flammability and its tendency to cause vomiting. In England, it was quickly replaced by chloroform, but this agent caused many deaths and lost popularity.

Did you know?

Opium has influenced much of the world's most popular literature. The following authors were all opium users, of varying degrees: Lewis Carroll, Charles, Dickens, Arthur Conan Doyle, and Oscar Wilde.

Did you know?

The immune system needs 9.5 hours of sleep in total darkness to recharge completely.

Did you know?

One way to reduce acid reflux is to lose two or three pounds. Most people lose weight in the belly area first when they increase exercise, meaning that heartburn can be reduced quickly by this method.

For a complete list of videos, visit our video library