Baffled boffins 'closer' to finding origins of extragalactic COSMIC RAYS

Uberbeams zap forth from deepest darkest space, says Delaware physicist


Scientists at the South Pole have moved a step closer to figuring out the origin point of the cosmic rays which can damage electronics on Earth and zap astronauts in space.

IceCube Lab by moonlight

The origin of the high-energy particles has been baffling boffins for decades, but the latest study, which uses data from the IceCube Neutrino Observatory at the South Pole, has uncovered new information about the rays at the level where Milky Way particles transition to extragalactic cosmic rays.

In our universe, cosmic rays are known to reach energies over 100 billion giga-electron volts (10¹¹ GeV). The latest study covers the energy range from 1.6 x 10⁶ GeV to 10⁹ GeV, which is the interval where the transition from the rays in our galaxy to those produced outside is expected to occur.

Boffins already know that supernovae are one of the sources of cosmic rays in the Milky Way, while collapsing stars and active galactic nuclei far from our galaxy are believed to produce the highest energy particles in nature.

The new study, headed by University of Delaware physicist Bakhtiyar Ruzybayev, found that the cosmic ray energy spectrum doesn't follow a simple power law between the "knee" around 4 PeV (peta-electron volts) and the "ankle" around 4 EeV (exa-electron volts) as previously thought.

“The spectrum steepens at the 'knee', which is generally interpreted as the beginning of the end of the galactic population. Below the knee, cosmic rays are galactic in origin, while above that energy, particles from more distant regions in our universe become more and more likely,” Ruzybayev explained.

He found that the spectrum exhibits features like hardening around 20 PeV and steepening around 130 PeV.

“These measurements provide new constraints that must be satisfied by any models that try to explain the acceleration and propagation of cosmic rays,” he added.

The data used in the study was gathered at IceTop, a configuration that now consists of 81 stations over a square kilometre of the South Pole above the detectors of IceCube, which are buried a mile deep in the ice. The full study, “Measurement of the cosmic ray energy spectrum with IceTop-73” (the 73 refers to a configuration of 73-station-array), was published in particle physics tome Physical Review D. ®

Similar topics

Broader topics


Other stories you might like

  • Stolen university credentials up for sale by Russian crooks, FBI warns
    Forget dark-web souks, thousands of these are already being traded on public bazaars

    Russian crooks are selling network credentials and virtual private network access for a "multitude" of US universities and colleges on criminal marketplaces, according to the FBI.

    According to a warning issued on Thursday, these stolen credentials sell for thousands of dollars on both dark web and public internet forums, and could lead to subsequent cyberattacks against individual employees or the schools themselves.

    "The exposure of usernames and passwords can lead to brute force credential stuffing computer network attacks, whereby attackers attempt logins across various internet sites or exploit them for subsequent cyber attacks as criminal actors take advantage of users recycling the same credentials across multiple accounts, internet sites, and services," the Feds' alert [PDF] said.

    Continue reading
  • Big Tech loves talking up privacy – while trying to kill privacy legislation
    Study claims Amazon, Apple, Google, Meta, Microsoft work to derail data rules

    Amazon, Apple, Google, Meta, and Microsoft often support privacy in public statements, but behind the scenes they've been working through some common organizations to weaken or kill privacy legislation in US states.

    That's according to a report this week from news non-profit The Markup, which said the corporations hire lobbyists from the same few groups and law firms to defang or drown state privacy bills.

    The report examined 31 states when state legislatures were considering privacy legislation and identified 445 lobbyists and lobbying firms working on behalf of Amazon, Apple, Google, Meta, and Microsoft, along with industry groups like TechNet and the State Privacy and Security Coalition.

    Continue reading
  • SEC probes Musk for not properly disclosing Twitter stake
    Meanwhile, social network's board rejects resignation of one its directors

    America's financial watchdog is investigating whether Elon Musk adequately disclosed his purchase of Twitter shares last month, just as his bid to take over the social media company hangs in the balance. 

    A letter [PDF] from the SEC addressed to the tech billionaire said he "[did] not appear" to have filed the proper form detailing his 9.2 percent stake in Twitter "required 10 days from the date of acquisition," and asked him to provide more information. Musk's shares made him one of Twitter's largest shareholders. The letter is dated April 4, and was shared this week by the regulator.

    Musk quickly moved to try and buy the whole company outright in a deal initially worth over $44 billion. Musk sold a chunk of his shares in Tesla worth $8.4 billion and bagged another $7.14 billion from investors to help finance the $21 billion he promised to put forward for the deal. The remaining $25.5 billion bill was secured via debt financing by Morgan Stanley, Bank of America, Barclays, and others. But the takeover is not going smoothly.

    Continue reading

Biting the hand that feeds IT © 1998–2022