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Astronomers Detected a 'Ghost Particle' and Tracked It To Its Source (space.com)
An anonymous reader quotes a report from Space.com: Astronomers have traced a high-energy neutrino to its cosmic source for the first time ever, solving a century-old mystery in the process. Observations by the IceCube Neutrino Observatory at the South Pole and a host of other instruments allowed researchers to track one cosmic neutrino to a distant blazar, a huge elliptical galaxy with a fast-spinning supermassive black hole at its heart. And there's more. Cosmic neutrinos go hand in hand with cosmic rays, highly energetic charged particles that slam into our planet continuously. So, the new find pegs blazars as accelerators of at least some of the fastest-moving cosmic rays as well. Astronomers have wondered about this since cosmic rays were first discovered, way back in 1912. But they've been thwarted by the particles' charged nature, which dictates that cosmic rays get tugged this way and that by various objects as they zoom through space. Success finally came from using the straight-line journey of a fellow-traveler ghost particle.
On Sept. 22, 2017, [...] IceCube picked up another cosmic neutrino. It was extremely energetic, packing about 300 teraelectron volts -- nearly 50 times greater than the energy of the protons cycling through Earth's most powerful particle accelerator, the Large Hadron Collider. Within 1 minute of the detection, the facility sent out an automatic notification, alerting other astronomers to the find and relaying coordinates to the patch of sky that seemed to house the particle's source. The community responded: Nearly 20 telescopes on the ground and in space scoured that patch across the electromagnetic spectrum, from low-energy radio waves to high-energy gamma-rays. The combined observations traced the neutrino's origin to an already-known blazar called TXS 0506+056, which lies about 4 billion light-years from Earth. The IceCube team also went through its archival data and found more than a dozen other cosmic neutrinos that seemed to be coming from the same blazar. These additional particles were picked up by the detectors from late 2014 through early 2015. The findings are reported in two separate studies published in the journal Science.
On Sept. 22, 2017, [...] IceCube picked up another cosmic neutrino. It was extremely energetic, packing about 300 teraelectron volts -- nearly 50 times greater than the energy of the protons cycling through Earth's most powerful particle accelerator, the Large Hadron Collider. Within 1 minute of the detection, the facility sent out an automatic notification, alerting other astronomers to the find and relaying coordinates to the patch of sky that seemed to house the particle's source. The community responded: Nearly 20 telescopes on the ground and in space scoured that patch across the electromagnetic spectrum, from low-energy radio waves to high-energy gamma-rays. The combined observations traced the neutrino's origin to an already-known blazar called TXS 0506+056, which lies about 4 billion light-years from Earth. The IceCube team also went through its archival data and found more than a dozen other cosmic neutrinos that seemed to be coming from the same blazar. These additional particles were picked up by the detectors from late 2014 through early 2015. The findings are reported in two separate studies published in the journal Science.
I'm just glad IceCube is doing something useful with the rest of his life.
I am wondering how they managed to find the source.
Does the detector give them a vector of direction? After that how many calculations are needed? I would think you would have to figure in Earth's rotation, Earth's orbit, the sun's orbit, and the galaxy's path. Presumably the neutrino was traveling somewhat below C so there must be an adjustment there. All that to get a direction to look. Am I off base on this or is it not that complex?
All I can say is Astronomers must have fiendish concentration skills for math.
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what a great discovery, big ups to the astronauts https://toponlineviews.tumblr....
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Bigly
I object to power without constructive purpose. --Spock
It's interesting subject matter, but the author is just completely and totally painful to read. I can't put my finger on what it is exactly though...
So 300TeV is 50 microjoules. The energy required to lift 1g by 1mm on Earth, if my maths is right. And this comes from a single neutrino. Mind blown...
You forgot baseball
How could they possible track where the neutrino came from given their incredibly sporadic observability for measurement, a spinning earth, a spinning solar system, a spinning arm of the milky way - and 4 billion light years distance?
The article says they notified astronomers of a patch of sky that was a candidate for the source - how could this be correct if our galaxy is spinning?
Again, apologies if this is a dumb question, but thank to Einstein I think everything's relative - especially the orientation of bodies ;).
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I am wondering how they managed to find the source.
When this neutrino interacted with the ice it converted itself into a muon which is a heavy cousin of the electron that can travel a huge distance through the ice at these energies. So what we saw was a track of light that moved through the whole ~1km width of the detector that we could then point back to a region of the sky. So we do not detect the neutrino itself only what it produces after an interaction and, if it produces a muon, we have a good long track if there is enough energy.
The light from the track is because the muon has a charge and travels incredibly close to the speed of light in vacuum. However, the speed of light in ice is quite a bit less than the speed in vacuum and so the muon emits a shockwave cone of light called Cherenkov radiation just like a supersonic aircraft emits a conical sonic shockwave of sound called the sonic boom.
Yes, they can track the neutrino through the detector, and that gives them a direction.
Not quite - we cannot see neutrinos directly. What we see are the particles they produce when they interact in the ice. At these energies, the boost of the particles created is so large that it basically has the same direction as the original neutrino. However, if the neutrino produces an electron or a tau (unless it is really high energy) this produces a cascade of particles which we see as a point source that has little to no pointing. Only when the neutrino produces a muon do we get a long track that we can point back to the source.
And also Don't forget Trump for 2020-2024!!!
Only till 2024? Are you kidding? Putin has already managed 18 years on an 8-year position.