What makes Quasars shine?

A place to hang out and chat about astronomy

What makes Quasars shine?

Postby jsc248 » Sun Aug 12, 2007 7:53 pm

Hi Gang,
We know that the light from quasars is so bright that it shines clear across the universe, but what is the quasar using for fuel? Astronomers now believe that they have solved the answer for at least some of the quasars. In a report from the Institute of Astronomy, astronomers using the Hubble Space Telescope have observed these supermassive black holes devouring material from surrounding gas rich galaxies. This almost pure hydrogen/helium mixture allows the quasars to produce incredible ammounts of energy. To read their report go here [url=http://www.ifa.hawaii.edu/info/press-releases/black_holes-8-07.html]http://www.ifa.hawaii.edu/info/press-releases/black_holes-8-07.html[/url]
John.
To me astronomy is looking up and thinking "What the heck is going on up there!!"
jsc248
 
Posts: 3511
Joined: Wed Apr 27, 2011 7:23 pm
Location: Huyton,Merseyside

RE: What makes Quasars shine?

Postby s_hawkins » Mon Aug 13, 2007 10:53 am

Taking nuclear fusion to the max! Quasars are strange objects...

Sam
s_hawkins
 
Posts: 1501
Joined: Mon Feb 13, 2012 6:30 pm

RE: What makes Quasars shine?

Postby robin_astro » Mon Aug 13, 2007 4:26 pm

[quote]ORIGINAL: S_Hawkins

Taking nuclear fusion to the max! Quasars are strange objects...
[/quote]

Not nuclear fusion. This would not provide anywhere near enough energy to power a quasar. Gravity is the source of energy.
[url=http://www.astronomynotes.com/galaxy/s14.htm]http://www.astronomynotes.com/galaxy/s14.htm[/url]
ISTR reading somewhere that typically around 10% of the rest mass of the infalling material is converted to energy in a quasar compared with less than 1% in a fusion reaction
[url=http://www.astronomynotes.com/starsun/s3.htm]http://www.astronomynotes.com/starsun/s3.htm[/url]

Robin
robin_astro
 
Posts: 213
Joined: Mon Feb 13, 2012 6:30 pm

RE: What makes Quasars shine?

Postby s_hawkins » Mon Aug 13, 2007 5:00 pm

I've done that a second time now! Thanks for correcting me. [:)]
s_hawkins
 
Posts: 1501
Joined: Mon Feb 13, 2012 6:30 pm

RE: What makes Quasars shine?

Postby daveye » Sat Aug 18, 2007 2:13 pm

I was always under the impression it was gravity, it's difficult for matter to fall directly into the black hole so it orbits and looses angular momentum, eventually falling in. So it all builds up and starts to bump into each other forming an accretion disc.

It gets to about ~30,000K if I can remmeber, giving out alot of UV. The spectra of these things is really interesting, they still don't really know the whole story.

The big problem is fueling them, quasars are around redshifts 3-5, because the accretion disc is a limit to how fast they can take in matter they formed too quickly for this model to work. The furthest away one currently seen is about redshift 5, if I can remmeber thats less than 10% the age of the universe!
daveye
 
Posts: 5
Joined: Mon Feb 13, 2012 6:41 pm


Return to General

Who is online

Users browsing this forum: Axoleaxia and 1 guest

cron