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13 billion year old GRB


Arch2008
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wow, thats really far away lol..Maybe towards the center of the universe?, what if we found the center, thatd be cool lol

 

The universe doesn't have a center. Or the center is everywhere, depending on how you look at it. To see the oldest light in the universe, you can look in any direction.

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Fascinating discovery! We were discussing most distant object (besides the CMB) which at that time was a gravitationally-lensed galaxy with a red shift of 7.6. But this beats that z = 8.2 means that thing is now over 30 Billion light years away. Could this GRB come from a galaxy, or a solitary Giant? It must have been a short-lived star.

 

The only way we can see that far is by a GRB or gravity lens.

Edited by Airbrush
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Great find! Thanks. Estimated redshift z = 8.2

 

I got z=7.875. Where am I going wrong?

(Edit - Ignore this line because it is from a different source)

 

Another thing I do not understand is the article said

 

" Distortions in the light signature of the object show it is 13 billion years old -- at the speed of light, 13 billion light-years away"

(Edit - From a different article then posted)

 

 

It can't be both because of the expansion of space but it is obvious they are saying it is 13 billion years old NOW. That would make it .665 billion years old at the age of redshift. The Ned Wright site also says it would have been 3.3465 Gly away when the light was omitted and is currently 29.7billion light years away.

 

My question is, if the universe was only .665 billion light years old when this GRB was omitted, is that long enough for a star to have formed, matured and then exploded?

 

If I am missing something here just tell me to get more sleep. :)


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Not likely, IMO. If it's a sphere, then all spacetime is on the surface of said sphere... The concept of a "center" or of something "inside the sphere" is completely meaningless.

 

I may be wrong but I thought a thick skinned sphere was one possibility. Not sure where that thought came from at the moment. My imagination is fairly active. :)


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It must have been a short-lived star...

 

You beat me to it.

Edited by NowThatWeKnow
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I may be wrong but I thought a thick skinned sphere was one possibility. Not sure where that thought came from at the moment. My imagination is fairly active. :)

 

Perhaps that came from taking the "surface of the balloon" analogy for expanding space too literally? It isn't accurate, though.

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http://www.astro.ucla.edu/~wright/CosmoCalc.html

 

When I plug 8.2 into where z is supposed to go and click Flat, I get 30.016 Billion LY away currently.

 

When I plug in 7.875 I get exactly 13 billion light years old and 29.7 billion light years away from us now. z=8.2 gives me 13.035 billion years old.

 

I see the problem though, I read a different article that rounded the #'s.


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Perhaps that came from taking the "surface of the balloon" analogy for expanding space too literally? It isn't accurate, though.

I found it. It was a combination of my imagination and that darn "Where Does Space End? It Must End Somewhere!" thread. My version of a non mainstream view. Glad I got that out of my head. :D

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This makes sense if the first stars formed about 400 Million years after the Big Bang. This would be among the first stars, a blue, hot supergiant that lived only tens or hundreds of Millions of years. It exploded 600 Million years after the Big Bang, then we saw it 13 Billion years later.

 

Is there any way to know the size of a star that causes a GRB?


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It was a combination of my imagination and that darn "Where Does Space End? It Must End Somewhere!" thread. My version of a non mainstream view. Glad I got that out of my head. :D

 

I don't think I can ever get that thick-skinned balloon out of my head. :D

 

Right after posting the above I turned on my radio and the first story on NPR was about this discovery! What a synchronicity.

Edited by Airbrush
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That star must have been huge if it lived that short..or maybe the universe is older than what we thought...and that star is older than what we think..hmm..If it was just a short lived star that lasted 600 or so million years, it must be like a blue super giant twice the size of a red supergiant...ahhh lol

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That star must have been huge if it lived that short..or maybe the universe is older than what we thought...and that star is older than what we think..hmm..If it was just a short lived star that lasted 600 or so million years, it must be like a blue super giant twice the size of a red supergiant...ahhh lol

 

Nowadays there are stars whose lifetimes are that short.

Check out

http://nrumiano.free.fr/Estars/sequence.html

 

If a star is very massive, it lives its life fast. The lifetime can be on the order of 1-10 million years.

So to have a star which exploded when the expansion age was 600 million years is not contradictory or surprising. It does not in any way suggest that the expansion "is older than what we thought". 600 million years is plenty of time for a massive star to condense and form and live its life to the end.

Edited by Martin
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After the "Dark Ages" ended when the first stars ignited, about 400 Million years after the Big Bang (ATBB), there was a period of about 200 Million years until our recent GRB of 13 Billion years ATBB. Many generations of extremely massive stars could have been born and exploded in less than 10 Million years for each one. Each supernova would put pressure on local gas clouds causing new massive stars to rapidly form. Maybe the recent GRB was not first generation, but a decendant of many previous stars.

 

If we see one GRB there could be thousands of others that were not alligned with Earth, so we would never see those.

 

"Some studies estimate that the very first stars of the universe could have had a much larger mass, perhaps up to 1000 solar masses. Of course, the lifetime of these stars was exceedingly short, but they would have sowed the universe with heavy elements quite early."

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Swift satellite has imaged the oldest object in the universe:

http://www.nasa.gov/mission_pages/swift/bursts/cosmic_record.html

 

 

Not true, it presents an image as it appeared 13 billion years ago at which it could have been no more than 2.5 billion years old - the earth is 4.5 billion years old. So to be a real pain in the arse it is NOT the oldest objext in the universe :)

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Not true, it presents an image as it appeared 13 billion years ago at which it could have been no more than 2.5 billion years old - the earth is 4.5 billion years old. So to be a real pain in the arse it is NOT the oldest objext in the universe :)

 

You are adding a couple of Billion years to the current estimates of the age of the universe. What does the age of the Earth have to do with it? It is not the oldest object, it is only the oldest VISIBLE object ever detected, and not thru visible light either, it is too red-shifted for that.

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Swift satellite has imaged the oldest object in the universe:

http://www.nasa.gov/mission_pages/swift/bursts/cosmic_record.html

 

There's been some quibbling about semantics of Arch's sentence.

I take it to mean

Swift satellite has imaged the oldest object in the universe that has been imaged so far. That seems true enough.

 

If the object is still intact today---presumably it became a black hole after the explosion---it must now be some 13 billion years old. Clearly extremely old.

 

Naturally our image of it is as it was when it was young. (The quibble that I think Meg was making.) But so what? Young when it emitted the light we are now receiving. But the object itself is old---the oldest macroscopic object we have direct specific information about.

 

In astronomy one can never image material objects as they are today, one only sees them as they were in the past.

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