Highest Ever Energy Light Captured By Chinese Mountain Observatory (sciencemag.org) 31
sciencehabit writes: Using an observatory on the edge of the Tibetan Plateau, astronomers have spotted the highest energy light ever, gamma ray photons up to 1.4 petaelectronvolts (PeV). They have traced these extreme photons back to a dozen of their likely sources: powerful factories in the Milky Way Galaxy that accelerate charged particles called cosmic rays. The results are challenging theorists' understanding of what these factories are and how they generate such high-energy light. "The findings are extremely important and impressive," says Petra Huentemeyer, an astrophysicist at Michigan Technological University and spokesperson for a rival gamma ray telescope, the High-Altitude Water Cherenkov Observatory (HAWC) in Mexico. "It's a giant leap toward finally understanding the origin of the highest energy cosmic rays."
Discovered more than 100 years ago, cosmic rays are charged particles, including protons and other atomic nuclei, that have been accelerated nearly to the speed of light. Their sources are poorly understood because interstellar magnetic fields bend them on their path to Earth. However, as cosmic rays rocket away from their sources, they also emit photons, usually about one-tenth as energetic as the cosmic rays themselves, that follow a straight path to Earth. Although Earth's atmosphere blocks this gamma ray light, when the photons slam into air molecules, they create showers of secondary particles and faint blue Cherenkov light that astronomers can look for. China's Large High Altitude Air Shower Observatory (LHAASO) aims to catch the air showers associated with the highest energy gamma rays, which in turn correspond to the highest energy cosmic rays.
Discovered more than 100 years ago, cosmic rays are charged particles, including protons and other atomic nuclei, that have been accelerated nearly to the speed of light. Their sources are poorly understood because interstellar magnetic fields bend them on their path to Earth. However, as cosmic rays rocket away from their sources, they also emit photons, usually about one-tenth as energetic as the cosmic rays themselves, that follow a straight path to Earth. Although Earth's atmosphere blocks this gamma ray light, when the photons slam into air molecules, they create showers of secondary particles and faint blue Cherenkov light that astronomers can look for. China's Large High Altitude Air Shower Observatory (LHAASO) aims to catch the air showers associated with the highest energy gamma rays, which in turn correspond to the highest energy cosmic rays.
Wavelength is (Score:4, Interesting)
8.8e-13 nm, or 8.8e-22 m. Which is one millionth the diameter of a proton.
Energy is (Score:4, Interesting)
More than two thousand ergs, a macroscropic amount on a single photon.
Outsourcing the universe. (Score:3, Funny)
They have traced these extreme photons back to a dozen of their likely sources: powerful factories in the Milky Way Galaxy that accelerate charged particles called cosmic rays. The results are challenging theorists' understanding of what these factories are and how they generate such high-energy light. "
Bet they're looking at how they can move these "factories" to China.
Calling Stan Lee (Score:2)
powerful factories in the Milky Way Galaxy that accelerate charged particles called cosmic rays
Do you want the Fantastic Four? Because that's how you get the Fantastic Four.
Re: Calling Stan Lee (Score:1)
Calling Stan Lee
You want a Stan Lee zombie?? Because that's how you get another bad plot.
I'm confused.... (Score:2)
So the Oh-My-God particle was a cosmic ray estimated at about 3x10^20 ev, and according to Wikipedia even higher energy ones have been detected. This one is listed as "1.4 petaelectronvolts", which to my understanding is 1.4x10^15 ev.
That seems to make this one about 10^-5 times the energy of the OMG particle; so how is this the "Highest ever energy light captured"?
Re:I'm confused.... (Score:5, Informative)
Your confusion stems from the summary, which confuses two entirely different things: photons and cosmic rays. The latter, despite the name "rays", are matter - typically iron nuclei, so can pack a significantly greater punch than the former, simply because they have rest mass while photons only have momentum.
In fact, it's not entirely clear how they get to that frequency. You can't just heat things up and get higher and higher resulting photon energies. The mostly likely candidate are emissions coming from the accretion disk of a massive black hole when it's spinning in the direction of the observer (Earth). The blue shift of light emitted from material speeding towards us at nearly the speed of light would get the frequency that high. In fact, that's probably where the "cosmic rays" come from as well.
Re: I'm confused.... (Score:2)
Thank you; here I was thinking that a Cosmic Ray was early terminology for Gamma Rays. I learned something today.
Re: (Score:2)
The Oh-My-God particle wasn't light, is the answer.
Doubtful (Score:3)
Re: (Score:2)
Apply a few palettes of salt on the reproducibility of these claims.
And why?
And how actually would YOU *reproduce* a cosmic ray? Perhaps it is a once in a century or once in a millenium event?
Re: (Score:2)
And why?"
Findings coming out of China have a reputation for often being science fiction. I've heard it relates to a strong state push to publish.
Re: (Score:2)
Findings coming out of China have a reputation for often being science fiction. I've heard it relates to a strong state push to publish.
Any examples?
And why would anyone invent/imagine a super strong cosmic ray?
Re: (Score:2)
"And why would anyone invent/imagine a super strong cosmic ray?"
Government incentives to publish. A push to show an expensive national science investment is producing results. For the same reasons we are hearing about it.
Other than money, reputation and a nationalist totalitarian regime's national pride... to impress the ladies?
Re: (Score:2)
Does not really sound plausible.
People publishing "fake papers" get punished in China more than anywhere else.
Sorry, you have an idiotic idea about "totalitarian China". they have no intention at all to impress anyone outside of China.
Chinese observatory on Tibet's land (Score:1)
The previous occupants of that land who protested forced relocation are probably now in the same camps as the Uyghers.
https://freetibet.org/news-med... [freetibet.org]
Subject (Score:1)
Word order frying my brain (Score:2)
Light? (Score:2)
Gamma rays are not light. Idiot journalists, as usual.
Re: (Score:2)
Re: (Score:2)
About 700 nanometres. But it's all still on the electromagnetic spectrum. We don't call radio waves light, either.