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

Author Question: Why are there few quasars at low redshifts and at high redshifts but many at redshifts of about 2? ... (Read 104 times)

panfilo

  • Hero Member
  • *****
  • Posts: 572
on: Jul 27, 2018
Why are there few quasars at low redshifts and at high redshifts but many at redshifts of about 2?
 
  What will be an ideal response?

Question 2

Planetary nebulae are sites of planet formation.
 
  a. True
  b. False
  Indicate whether the statement is true or false


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

karmakat49

  • Sr. Member
  • ****
  • Posts: 369
Reply #1 on: Jul 27, 2018
Answer to Question 1

Quasars are most common with redshifts over 2 and less common with redshifts above 3 . The largest quasar redshifts are over 6, but such high-redshift quasars are rare. Evidently astronomers see few quasars at high redshifts because they are looking back to an age when the Universe was so young it had not yet formed many galaxies. At redshifts between 2 and 3, galaxies were actively growing and colliding, and quasars were about 1000 times more common than they are now.

Answer to Question 2

False


panfilo

  • Member
  • Posts: 572
Reply 2 on: Jul 27, 2018
:D TYSM

bigsis44

  • Member
  • Posts: 317
Reply 3 on: Yesterday
Gracias!

« previous next »
 

Did you know?

Chronic necrotizing aspergillosis has a slowly progressive process that, unlike invasive aspergillosis, does not spread to other organ systems or the blood vessels. It most often affects middle-aged and elderly individuals, spreading to surrounding tissue in the lungs. The disease often does not respond to conventionally successful treatments, and requires individualized therapies in order to keep it from becoming life-threatening.

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?

In most cases, kidneys can recover from almost complete loss of function, such as in acute kidney (renal) failure.

Did you know?

Illicit drug use costs the United States approximately $181 billion every year.

Did you know?

Your skin wrinkles if you stay in the bathtub a long time because the outermost layer of skin (which consists of dead keratin) swells when it absorbs water. It is tightly attached to the skin below it, so it compensates for the increased area by wrinkling. This happens to the hands and feet because they have the thickest layer of dead keratin cells.

(c) snow in Nunavut, alter the local albedo, causing altered microclimates. High albedos are found (c) snow in Nunavut, alter the local albedo, causing altered microclimates. High albedos are found
From high cotransduction frequencies, close linkage is inferred From high cotransduction frequencies, close linkage is inferred
These adolescents have just graduated and look forward to moving on from high school and adolesence These adolescents have just graduated and look forward to moving on from high school and adolesence
Mononucleosis is caused by the Epstein–Barr virus. Symptoms of the infectious disease are swollen pa Mononucleosis is caused by the Epstein–Barr virus. Symptoms of the infectious disease are swollen pa
The High Plains Aquifer The High Plains Aquifer
The distribution of high-energy, nutritious biscuits was a lifeline in the first days after the 2010 The distribution of high-energy, nutritious biscuits was a lifeline in the first days after the 2010
Video: Proteins

For a complete list of videos, visit our video library