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Author Topic: Black Hole X-rays?  (Read 4554 times)

Offline JimBob

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Black Hole X-rays?
« on: 14/06/2006 02:02:12 »
How do black holes - more accurately, their surronding gases - emit x-rays?

[?]   |   [?]



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ROBERT

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Re: Black Hole X-rays?
« Reply #1 on: 14/06/2006 15:06:38 »
If gas is heated to millions of degrees it will produce X-rays.
This occurs in the corona of stars , (including our sun).
 

Offline JimBob

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Re: Black Hole X-rays?
« Reply #2 on: 14/06/2006 15:12:30 »
Thank you ROBERT

Can you go into a little more depth?



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ROBERT

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Re: Black Hole X-rays?
« Reply #3 on: 14/06/2006 16:02:05 »
quote:
Originally posted by JimBob

Thank you ROBERT

Can you go into a little more depth?



At temperatures of millions of degrees the collisions between atoms are of such high energy that electrons from their inner shell are knocked out, electrons from the outer shells fill this vacancy in the inner shell,
 in doing so they emit a high-energy photons of X-ray wavelength.
« Last Edit: 14/06/2006 17:53:38 by ROBERT »
 

Offline JimBob

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Re: Black Hole X-rays?
« Reply #4 on: 14/06/2006 18:15:07 »
Muchos gracias, senior.

:D



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Offline jmferg

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Re: Black Hole X-rays?
« Reply #5 on: 18/06/2006 21:40:42 »
sorry but I thought the question was more along the lines of if nothing can escape the gravity of a blackhole not even light then how do the x-rays escape, my under standing being that x-rays are a type of light.
 

Offline Soul Surfer

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Re: Black Hole X-rays?
« Reply #6 on: 18/06/2006 23:54:15 »
jmferg:-  Black holes may have enormous gravitational fields but it is quite difficult to fall into one because they are extremely small on a cosmic scale and as you drop into their field you are very likely to miss the hole and go round in a tight orbit and escape. However there is sometimes a lot of other stuff doing the same thing and so you are quite likely to hit something else at high speed.  This is where the radiation including X-rays comes from.  That is bits of stuff bumping into one another and generally destroying themselves before they slow down enough to fall into the event horizon.  It is calculated that material will radiate something like 50% of its total rest mass before falling into the hole. A black hole is by far the most efficient way of turning matter into energy there is.  Much more efficient than the next best which is nuclear fusion turning hydrogen ito helium which only releases a few percent.

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Offline Solvay_1927

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Re: Black Hole X-rays?
« Reply #7 on: 19/06/2006 02:33:41 »
Ian, I thought Hawking radiation was generated by quantum fluctuations near the event horizon (particle-antiparticle creations where one of the particles gets swallowed by the hole, leaving the other to carry away energy). What you describe sounds different.  Is my understandig mistaken? Or is it just that the radiation due to the quantum fluctuations is negligible compared to the radiation from the collisions you describe?
 

another_someone

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Re: Black Hole X-rays?
« Reply #8 on: 19/06/2006 03:00:27 »
quote:
Originally posted by Solvay_1927
Ian, I thought Hawking radiation was generated by quantum fluctuations near the event horizon (particle-antiparticle creations where one of the particles gets swallowed by the hole, leaving the other to carry away energy). What you describe sounds different.  Is my understandig mistaken? Or is it just that the radiation due to the quantum fluctuations is negligible compared to the radiation from the collisions you describe?



What Ian is talking about is nothing to do with Hawkins, it is merely ordinary matter falling into a black hole, effectively getting compressed as it approaches the black hole, and the heat of that compression radiation energy away from the black hole before it even gets to the black hole.



George
 

Offline ukmicky

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Re: Black Hole X-rays?
« Reply #9 on: 19/06/2006 03:12:44 »
Hi paul   nice to hear from you again.

What i believe ian (soul surfer) is talking about is the x rays etc which eminate from the accretion ring surrounding an actively feeding blackhole


Michael
 

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Re: Black Hole X-rays?
« Reply #9 on: 19/06/2006 03:12:44 »

 

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