View Full Version : Discussion: Iron Can Help Determine if a ...

2003-Sep-17, 10:29 PM
SUMMARY: Astronomers have used the Chandra X-Ray Observatory to examine the presence of iron in three stellar black holes to understand if they're spinning or not. In theory, a spinning black hole will drag space around it and permit atoms to exist closer than a non-spinning one - Chandra can detect the relativistic effects on iron atoms orbiting the black hole. The explanation for different spin rates could be due to the size of a black hole's source of material; the larger the source (like a big star) and longer feeding time, the faster the black hole spins.

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2003-Sep-19, 01:51 AM
Out in the middle of space like that, where would iron come from in the first place?

2003-Sep-19, 05:03 AM
Ya, the iron could come from a star that a black hole has "eaten". And from that last amont of matterial, which is usually the heaviest found in a star, the black hole could cause it to come near the even horizon.

So, what would happen next? probably fast spinning iron ions.

But what if these iron ions where caused by "relatavistic" effects, ie. fast motions approaching the speed of light, and would this not cause the iron to have a higher mass, because it is in high motion. And after that, maybe the electrons would be striped away by this high speed. Then would come the breaking up of the strong nucleus and it's strong nuclear forces inside the protons and neutrons. This decay would release large amounts of energy which could be one explanation of the spinning.

But wouldn't it also be easier to picture the black hole revolving around the sun which provides it with that iron? Because relitivly speaking, the frame of reference would not matter. Except, that since the black hole revolves around the sun, and attracts the sun's matterial with it's own gravity, the trail of matterial would seem, to another observer (say us), as if it were the black hole that was spinning instead of the star. But eventually, the black hole would be the one that is spinning, due to it's motion with the star before it consumed it and did the above (the star decaying).

So, depending on the number of stars "eaten" the spin of a black hole would increase with the number of stars.

Thats what i see happening, but it all could be wrong! :huh: