Jump to content




another question about black holes

Recommended Posts

was wondering the other day we know that nothing can escape from a black hole not even light,but then i watched something that said black holes emit jets of radiation,how can this be if not even light can escape? is there a sweet spot in the centre that is weaker so allows the radiation to escape and if so wouldn't there be a white dot where that sweet spot is where light is managing to escape or am i barking up the completely wrong tree (which is my guess!)

Link to comment
Share on other sites

I think I understand Hawkins radiation, it's just the animation I have seen seems to show a beam of radiation coming from the centre of the black hole and as George stated Hawkins radiation comes from the edge of the event horizon. Thanks for all the help guys

Edited by starstalker
Link to comment
Share on other sites

I rememeber seeing a tv program where it shows the ray coming from the centre and being expelled at 90deg to the galaxy both top and bottom... I dont remember what program it was though


Edited by Keiran
Link to comment
Share on other sites

Its the radiation being emitted from the super heated gas of particles falling into the black hole. They gain a lot of energy falling in, and some of it comes out as radiation or jets of particles. The magnetic field produced means it comes out in a tight cone. This is very different to hawking radiation.

Its believe these are the power behind AGN, a blazar being one where the cone is directly lined up with our line of sight.

Link to comment
Share on other sites

Just been to a seminar on AGNs and black holes. Now understand it much better!

If its a fast growing black hole, its basically radiation pressure of light that is in balance with the infalling matter - Eddingtons limit. In this case you see a lot of luminance in the visible and higher wave bands.

For slower growing black holes, the excess energy is remove mechanically, by jets of material focused by the strong magnetic fields generated.

So that's why we see Quasar type objects - shining brightly, and others with jets that emit more in the radio spectrum. The growth rate is influenced by the age and type of galaxy.

There you go - an hours talk condensed!

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.