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As Dr. Weaver speaks, we see the X-ray tube at a dentist office positioned
for taking an X-ray. We then see the X-ray film of someone's teeth.
We see Dr. Weaver as she says that the objects in the sky produce the X-rays.
We then see an artist's rendition of the Astro-E2 satellite in
space.
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KIM WEAVER: In X-ray astronomy, it's not like going to the
dentist. The dentist takes an X-ray by shooting X-rays at you and on
the other side they have a piece of film that collects the X-rays and
that's how you see the X-ray shadow. In astronomy, we're not
producing the X-rays ourselves, the objects out there - the stars, the
supernovae, the galaxies, the black holes - are producing the X-rays. And then we send up a telescope that just detects the X-rays. |
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This clip continues with artist's animation of a zoom in to a black hole.
The black hole is surrounded
by an outermost thin disk of gas, and a thick torus closer to
the black hole. We also see jets eminating apparently
from the center.
As we zoom in more, we see the torus rotating. Our view
then peers over the torus and we see the central black hole.
There is a thin disk of gas between the inner edge of the torus
and the black hole. There is a gap between the innermost edge of
this disk and the black hole itself. We also see a jet of
material from the black hole. The jet consists of both a faint
funnel, and an innermost dense stream.
The torus and inner disk split to show us a cutaway view.
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KIM WEAVER: Black holes have extreme gravity and they have a lot of intensity and heat and energy around them, and so the regions around a black hole are going to be producing X-rays as opposed to optical light, so if you are going to probe a black hole, you need to be able to see X-rays.
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We see an optical image of Centaurus A, which shows a galaxy having a bright
nucleus and dark band across the middle. We then see two successive
images of the core of the galaxy, which show more detail of the gas
(which is bright) and the dust (which is dark).
We then see an X-ray image of this region, which shows a bright
diagonal line eminating from the center of the galaxy.
We finally see an artist's concept of a black hole, which shows a
beam eminating from the center (like the diagonal line in the X-ray
image), and a bright oblong disk around the black hole.
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KIM WEAVER: A galaxy is filled with all sorts of stars and gas and dust. And that gas and dust blocks our view to the center of the galaxy. So if we look at it in optical light, we can't see the center of the galaxy, because there's all the dust in the way. But in an Active Galactic Nucleus that has a huge black hole in the center that gives off X-rays around it, around it in an accretion disk, you can use those X-rays to probe into the center of the galaxy. So, you can see through the gas and dust.
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