| 
  • If you are citizen of an European Union member nation, you may not use this service unless you are at least 16 years old.

  • Stop wasting time looking for files and revisions. Connect your Gmail, DriveDropbox, and Slack accounts and in less than 2 minutes, Dokkio will automatically organize all your file attachments. Learn more and claim your free account.

View
 

Quasars 2012

Page history last edited by shankar.choudhury 8 years, 7 months ago

Quasars is a very not-well-known object of space, which in fact, is a major source in discovering the origin of the universe!  Quasars are supermassive black holes that become the centers of galaxies.  A Quasar becomes a Quasar when a massive black hole captures a large amount of matter, making a mini-galaxy, because the matter revolves around the black hole.  They are so massive that they are sometimes three billion times the weight of our sun!  The luminous energy output is even more amazing.  They can have about two trillion times the luminous energy output as the milky way!  The reason why they are so bright is that the dust captured by the massive black hole collide, emitting energy in the form of light.  When you think about it, that's a lot of dust colliding (we are talking in the trillions)!  

 

 

An artist’s rendering of the most distant quasar

An artist's rendering of ULAS J1120+0641, the farthest known quasar from us.  The black hole has a solar mass of two billion.  The stream of light (dust particles) classifies this quasar as a blazar.

 

Quasars were discovered when radio telescopes in the 1950's started picking up radio waves from unknown sources.  Soon, hundreds of these certain radio waves were being recorded.  The astronomers could tell that they were coming from a source very far away (in light year terms), but they could find the source.  They believed that we could see the source, but when they looked, all they saw was just stars.  in the 1960's astronomers pinpointed an emitter of one of the radio waves, but all they saw was what appeared a blue star.  The astronomers pursued their findings, and with calculation, they found that this "star" was very far away, but to be that far away, this object must be many times brighter than most galaxies.  The subject was not pursued because the results were too mind boggling for scientists to comprehend.  Than, in the 90's, astronomers resumed studying these very far away emitters of radio waves.  With calculations, quasars are thought to be between 780 million to 28 billion light years away!  If they are that far away, that means they existed near the beginning of the universe!  Yet another key in finding the origin of the Universe, and possibly "seeing" beyond the observable universe.  

 

 

SDSS J1254+0846

A picture from Chandra, a satellite, of a quasar.  From eyesight, it would look like another star in the sky, but in fact, this one is about 4.6 billion light years away.  

 

Quasars are thought to have existed even before the creation of stars (the earliest galaxy was created about 750 million years after the big bang).  Stars have thought to existed about 150 million years after the big bang.   Every object has what is called a schwarzschild radius.  This is where an object retains it's mass, but is shrunk down to a very small space.  The massive density ratio wise to the volume would create a gravity force so massive it would match one of a black hole.  For instance, if you could shrink Mt. Everest into something smaller than a nanometer, but retain the same mass, it would reach it's schwarzschild radius, and become  a like-black hole.  Even the biggest stars, when they collapse, the black hole is extremely small compared to the star.  Another thing about the schwarzschild radius is that it is proportional.  If a black hole has the same mass as our sun , who's radius is about 700,000 kilometers, it's radius (horizon) would be about three kilometers.  That means the radius of a big quasar (three billion times heavier than our sun) would be about three million kilometers.  That means, the star that collapsed into this black hole would have to have a radius of about 700 billion kilometers.  Creating a star this big would be nearly impossible, considering the amount of chance that a nebula is so uniform, and that the star would collapse on itself before it was complete.  So, how can Quasars be so big?   

 

Astronomers and astrophysicists  have yet to discover what created Quasars, but they think that the mysterious dark matter and dark energy may have something to do with the creation of Quasars. Dark matter and dark energy are theoretical names for the mysterious forces that make up nearly 95 percent of the Universe.  We currently know that the black holes that form quasars can never be created again.   It is general knowledge in the scientific world know that something about the dark energy and matter plus all the energy at the beginning of the universe had something to do with making these massive black holes.  Perhaps the universe was so unstable that certain areas of space formed depressions and collapsed on itself. 

 


This is a picture of a life cycle of a star.  This is not to scale though, the black hole would be about the size of Alaska, and the supergiant would not be fitting on this picture.

 

There are many types of quasars.  What I mean is that there are quasars that shoot out very strong radio waves in a random fashion, while others constantly emit radiation waves everywhere.  There are blazars, which are quasars that shoot out dust particles from either ends.  We so far have discovered about 500,000 quasars.  Only about ten percent of quasars emit radio waves, the rest emit lots of radiation waves and especially gamma rays.  The quasars are too far away for the gamma rays to affect us, but solar systems a lot closer to it could be affected by the gamma rays.  Randomly, quasars will shoot out very focused streams of gamma rays, having the diameter of jupiter on average.  If planet Earth was hit with one of these rays full on, all of life would be erased.  Thankfully, that will never happen.  

 

 

Another picture from chandra of PKS-1227-145, one of the most distant and brightest quasars discovered.  The stream of dust particles is estimated to be about a million light years long. 

 

Astronomers and astrophysicists  have yet to discover what created Quasars, but they think that the mysterious dark matter and dark energy may have something to do with the creation of Quasars. Dark matter and dark energy are theoretical names for the mysterious forces that make up nearly 95 percent of the Universe.  We currently know that the black holes that form quasars can never be created again.   It is general knowledge in the scientific world know that something about the dark energy and matter plus all the energy at the beginning of the universe had something to do with making these massive black holes.  Perhaps the universe was so unstable that certain areas of space formed depressions and collapsed on itself. 

 

 

Links:

http://en.wikipedia.org/wiki/Quasar

http://keckobservatory.org/news/keck_subaru_telescopes_find_rare_galaxy_at_dawn_of_time

http://imagine.gsfc.nasa.gov/docs/dict_qz.html#singularity

http://www.youtube.com/watch?v=3pAnRKD4raY

http://cosmology.berkeley.edu/Education/BHfaq.html

http://e.gsfc.nasa.gov/docs/science/know_l1/active_galaxies.html

 

Pictures

http://www.eso.org/public/images/eso1122a/

http://chandra.harvard.edu/photo/2010/sdss/

http://learn.uci.edu/oo/

 

 

 

 

 

 

 

 

Comments (0)

You don't have permission to comment on this page.