Question on Gamma Ray Time Lags

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The Code
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Question on Gamma Ray Time Lags

Post by The Code » Thu Jan 28, 2010 6:03 pm

NASA's Fermi gamma-ray space telescope. has observed high-energy photons arriving up to 20 minutes behind smaller low-energy ones from a source 12 billion light years away. Why the Lag?

Mark
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bystander
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Re: Question

Post by bystander » Thu Jan 28, 2010 6:37 pm

mark swain wrote:NASA's Fermi gamma-ray space telescope. has observed high-energy photons arriving up to 20 minutes behind smaller low-energy ones from a source 12 billion light years away.
Source?

http://asterisk.apod.com/vie ... =8&t=17555

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RJN
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Re: Question

Post by RJN » Thu Jan 28, 2010 7:03 pm

Many times source events just take that long or longer. A gamma-ray burst (GRB), which I believe is the source here, can keep emitting gamma rays for over an hour after the initial photons get emitted.

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Re: Question

Post by The Code » Thu Jan 28, 2010 7:11 pm

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RJN
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Re: Question

Post by RJN » Thu Jan 28, 2010 7:32 pm

Thanks for the link. That clears things up a bit. I believe the galaxy Markarian 501 gamma-ray measurement occurred in 2005. There is later data that, I believe, better confines quantum gravity-related dispersion with GRBs. Please see:
http://arstechnica.com/science/news/200 ... -burst.ars

The Code
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Re: Question

Post by The Code » Thu Jan 28, 2010 8:03 pm

Quantum gravity theories wiped out by a gamma ray burst, Oh dear.

Hey, maybe Quantum Gravity, decided 'It' was going to fool us. :lol:

Thanks for the interesting link RJN.

Mark
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