This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: The mass of visible matter in a galaxy can be estimated by measuring its luminosity. When this is ... (Read 28 times)

ss2343

  • Hero Member
  • *****
  • Posts: 548
on: Jul 27, 2018
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
Reply #1 on: Jul 27, 2018
Answer to Question 1

d

Answer to Question 2

c


ss2343

  • Hero Member
  • *****
  • Posts: 548
Reply #2 on: Jul 27, 2018
Thanks


ErinKing

  • Sr. Member
  • ****
  • Posts: 362
Reply #3 on: Jul 27, 2018
Welcome :)


« previous next »
 

Did you know?

The first war in which wide-scale use of anesthetics occurred was the Civil War, and 80% of all wounds were in the extremities.

Did you know?

In 1844, Charles Goodyear obtained the first patent for a rubber condom.

Did you know?

A serious new warning has been established for pregnant women against taking ACE inhibitors during pregnancy. In the study, the risk of major birth defects in children whose mothers took ACE inhibitors during the first trimester was nearly three times higher than in children whose mothers didn't take ACE inhibitors. Physicians can prescribe alternative medications for pregnant women who have symptoms of high blood pressure.

Did you know?

Sildenafil (Viagra®) has two actions that may be of consequence in patients with heart disease. It can lower the blood pressure, and it can interact with nitrates. It should never be used in patients who are taking nitrates.

Did you know?

If all the neurons in the human body were lined up, they would stretch more than 600 miles.

Measuring Limb Circumference Measuring Limb Circumference
Why Different Constellations Are Visible at Different Times of the Year Why Different Constellations Are Visible at Different Times of the Year
Measuring the Specific Gravity of Urine with a Refractometer Measuring the Specific Gravity of Urine with a Refractometer
Calculation of body mass index. To determine your BMI, find the value for your height on the left ... Calculation of body mass index. To determine your BMI, find the value for your height on the left ...
Mass Wasting Forms Mass Wasting Forms
Video: Digestive chemicals - water, gastric acid, bile & bicarbonate

For a complete list of videos, visit our video library