B Blazar as the Source of Cosmic Neutrinos Confirmed

[jedishrfu]

An international team of scientists has found the first evidence of a source of high-energy cosmic neutrinos, ghostly subatomic particles that can travel unhindered for billions of light years from the most extreme environments in the universe to Earth.

The observations, made by the IceCube Neutrino Observatory at the Amundsen-Scott South Pole Station and confirmed by telescopes around the globe and in Earth's orbit, help resolve a more than a century-old riddle about what sends subatomic particles such as neutrinos and cosmic rays speeding through the universe.

Since they were first detected over one hundred years ago, cosmic rays—highly energetic particles that continuously rain down on Earth from space—have posed an enduring mystery: What creates and launches these particles across such vast distances? Where do they come from?

Read more at: https://phys.org/news/2018-07-century-old-riddle-resolveda-blazar-source.html

and a second article from Ars Technica:

https://arstechnica.com/science/201...ino-source-a-black-hole-jet-pointed-at-earth/

showing how multi-messenger astronomy is revolutionizing science.

And lastly, this NBC news article:

https://www.nbcnews.com/mach/scienc...tant-galaxy-astronomy-breakthrough-ncna890911

 

[.Scott]

From that phys.org article...

The reason they are confident about the source is not just its location, but the timing of a flare up:

Fermi was the first telescope to identify enhanced gamma-ray activity from TXS 0506+056 within 0.06 degrees of the IceCube neutrino direction. In a decade of Fermi observations of this source, this was the strongest flare in gamma rays, the highest-energy photons. A later follow-up by MAGIC detected gamma rays of even higher energies.

The neutrino was interesting because of the power it packed:

Particles of particular interest to the IceCube team pack a more energetic punch. The neutrino that alerted telescopes around the world had an energy of approximately 300 TeV. (The energy of the protons circulating in the 26.7-kilometer ring of the Large Hadron Collider is 6.5 TeV.)

 

[Vanadium 50]

All of these popular articles missed the point. The point is not that one blazar sent one cosmic ray to Earth and it was detected. The point is that the same acceleration parameters work for a wide range of cosmic ray detections, and that many/most/all of the high energy cosmic rays come from AGNs.

 

[Involute]

Vanadium:

Since the charged particles that comprise cosmic rays would travel a different path through space than neutrinos from the same source, would we ever expect to see both types of particles arrive at Earth at the same time from the same direction, or even different directions? If so, why? If not, without that correlation between time of arrival and direction, how do we know the blazar isn’t just a source of high energy neutrinos? How do we know it’s also producing the other components of cosmic rays, which may be produced by some other, as yet undiscovered mechanism?

 

[diogenesNY]

Coverage in the NY Times: https://www.nytimes.com/2018/07/12/science/space-neutrinos-blazar.html

and the article in Science: http://science.sciencemag.org/content/early/2018/07/11/science.aat2890

diogenesNY

 

[nikkkom]

Vanadium:

Since the charged particles that comprise cosmic rays would travel a different path through space than neutrinos from the same source, would we ever expect to see both types of particles arrive at Earth at the same time from the same direction, or even different directions?

Sure, charged particles' direction of travel is sufficiently messed up by interstellar / intergalactic magnetic fields to make it impossible to track their origin.

This observation was of uncharged particles (gamma rays and neutrinos), whose direction of travel can only be altered by a rather strong gravitational field.

 

[Involute]

Coverage in the NY Times: https://www.nytimes.com/2018/07/12/science/space-neutrinos-blazar.html

and the article in Science: http://science.sciencemag.org/content/early/2018/07/11/science.aat2890

diogenesNY

Thanks, but the first doesn't answer my question and the second is over my head, though the abstract suggests it doesn't answer it either.

 

[Involute]

Sure, charged particles' direction of travel is sufficiently messed up by interstellar / intergalactic magnetic fields to make it impossible to track their origin.

This observation was of uncharged particles (gamma rays and neutrinos), whose direction of travel can only be altered by a rather strong gravitational field.

So, to slightly rephrase my original question, why "would we ever expect to see both types of particles arrive at Earth at the same time from the same direction, or even different directions?"

 

[nikkkom]

Probably not