Blazar as the Source of Cosmic Neutrinos Confirmed

  • B
  • Thread starter jedishrfu
  • Start date
  • #1
12,517
6,307
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
 
Last edited:
  • Like
Likes krater, Spinnor and BvU

Answers and Replies

  • #2
.Scott
Homework Helper
2,677
985
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.)
 
  • #3
Vanadium 50
Staff Emeritus
Science Advisor
Education Advisor
26,423
9,936
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.
 
  • Like
Likes Greg Bernhardt
  • #4
12
0
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?
 
  • #6
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.
 
  • #8
12
0
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?"
 
  • #9
Probably not
 

Related Threads on Blazar as the Source of Cosmic Neutrinos Confirmed

  • Last Post
Replies
2
Views
3K
  • Last Post
Replies
6
Views
3K
  • Last Post
Replies
1
Views
868
  • Last Post
Replies
10
Views
3K
  • Last Post
Replies
7
Views
1K
Replies
1
Views
2K
Replies
4
Views
2K
Replies
7
Views
1K
Top