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Like a lot of kids, I grew up reading about neutrinos

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and people speculating about doing neutrino astronomy.

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And here I am, doing neutrino astronomy, I feel like I need

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to pinch myself. My name is Roopesh Ojha,

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and I'm an astronomer working at the Goddard Space Flight Center.

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I work with the Fermi Gamma-ray Space Telescope. What we

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have been able to establish, for the first time, is an individual

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blazar as a potential birthplace of an individual neutrino.

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The Fermi Gamma-ray Space Telescope has an instrument called the Large Area Telescope, which

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we use to monitor the gamma-ray sky-the highest-energy electromagnetic band.

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And we just noticed that there was a tremendous

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increase in the amount of gamma-ray light coming from this one extra-galactic blazar.

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A blazar is an extremely powerful, variable,

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galaxy that is powered by a supermassive black hole.

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It went up not by a little bit, not by a few percent, it

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went up, like, 15 to 30 times its average flux.

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So we knew something was afoot, later on it

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turned out to be coincident, both in time and in space, with

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the neutrino that was detected by IceCube.

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IceCube is a neutrino telescope located at the South Pole, or to be

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more precise, under it.

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It consists of over 5,000 detectors that are spread out into a

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cube about a kilometer on each side.

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It's the world's biggest and it's coolest telescope.

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So a neutrino is an incredibly small

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particle, it moves almost at the speed of light,

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it is nearly massless, it's incredibly plentiful,

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but, it's very, very hard to detect because it

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will not interact with just about anything. If you could detect

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them though, because they have traveled through the universe essentially undeflected,

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they have information that you could not access in any other way.

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IceCube has detected a handful of extremely energetic

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neutrinos. One of them, which is called Big Bird, has an energy of

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about 2 peta-electron volts. To give you an idea of how much energy

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that is, it is about a million, million times the

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energy of dental X-ray. IceCube sees too large

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a patch of sky to let us determine exactly which blazar Big Bird

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came from. The enormous increase in gamma-ray flux seen by

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LAT and radio flux by other TANAMI telescopes let us finger

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the exact blazar which is responsible for Big Bird.

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We have long suspected that blazars are the birthplaces

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of such neutrinos. What we have been able to establish, for the

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first time, is an individual blazar as a potential

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birthplace of an individual neutrino. This is the first time that we can point

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and say "That blazar is where this neutrino came from."

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Blazars are the brightest steadily shining

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objects in the universe. However, many of the most basic questions

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about them, such as what is producing this tremendous amount of

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energy, remain open, and unanswered. The same process

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that produces this neutrino could also produce gamma rays,

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and that would move us closer to an understanding of emission from near black holes

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in blazars. [Music]

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[Music]

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[Music]

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[Music]

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[Beeping]

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[Beeping]