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 95 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
Gracias!

bimper21

  • Member
  • Posts: 309
Reply 3 on: Yesterday
Excellent

« previous next »
 

Did you know?

The Centers for Disease Control and Prevention (CDC) was originally known as the Communicable Disease Center, which was formed to fight malaria. It was originally headquartered in Atlanta, Georgia, since the Southern states faced the worst threat from malaria.

Did you know?

HIV testing reach is still limited. An estimated 40% of people with HIV (more than 14 million) remain undiagnosed and do not know their infection status.

Did you know?

There are approximately 3 million unintended pregnancies in the United States each year.

Did you know?

Approximately one in three babies in the United States is now delivered by cesarean section. The number of cesarean sections in the United States has risen 46% since 1996.

Did you know?

As many as 28% of hospitalized patients requiring mechanical ventilators to help them breathe (for more than 48 hours) will develop ventilator-associated pneumonia. Current therapy involves intravenous antibiotics, but new antibiotics that can be inhaled (and more directly treat the infection) are being developed.

(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
On the slopes of Chimborazo, a 6,310 m high volcanic peak in the Andes Mountains of Ecuador, Alexand On the slopes of Chimborazo, a 6,310 m high volcanic peak in the Andes Mountains of Ecuador, Alexand
An adult male giraffe feeding high up on an acacia An adult male giraffe feeding high up on an acacia
Membership in this subculture is not easily awarded. Not only must high-steel ironworkers prove that ... Membership in this subculture is not easily awarded. Not only must high-steel ironworkers prove that ...
Cloud Types: High Clouds Cloud Types: High Clouds
Hot spots highlight areas of high biodiversity Hot spots highlight areas of high biodiversity
Video: Vascular tissues in a corn stem and a buttercup root

For a complete list of videos, visit our video library