All articles tagged with #neutrinos
Researchers propose that some IceCube neutrino detections are magnified by gravitational lensing from a dark-matter filament deflecting emissions from the blazar PKS 2233-148, a finding that could sharpen our view of how neutrinos are produced and the black hole at a blazar’s core.
Astronomers report that the jet from a distant blazar (PKS 2233-148) is being gravitationally lensed by an unseen dark-matter clump, temporarily magnifying the jet and potentially aiding the search for high-energy neutrino sources; the finding, supported by VLBA, Fermi, and Swift observations and published in Monthly Notices of the Royal Astronomical Society, offers a first hint that dark-matter substructure can produce lensing effects in relativistic cosmic jets.
IceCube mapped the Milky Way with high-energy neutrinos over a decade, using deep learning to extract a faint galactic signal concentrated along the plane and toward the Galactic Center; the findings strongly indicate the Milky Way itself emits high-energy neutrinos, though no individual sources were pinpointed, and they pave the way for future IceCube upgrades and multimessenger studies.
From Pauli’s proposal to a lineage of colossal underground, underwater, and under-ice detectors, scientists have built ever-larger traps to catch neutrinos. Early solar-neutrino measurements at Homestake sparked a long puzzle that was resolved by experiments like Kamiokande, Super-Kamiokande, and SNO, which revealed neutrino oscillations and mass. Today, IceCube, KM3NET, Borexino, JUNO, Hyper-Kamiokande, and DUNE continue the hunt, probing neutrino properties across the cosmos and Earth with unprecedented precision.
Betelgeuse, the bright red supergiant in Orion, will someday explode as a supernova but likely not for about 100,000 years. New observations strengthen the case that Betelgeuse has a binary companion (Betelgeuse B) hidden in its glare, which could influence its evolution. When it finally collapses, the explosion will unleash an enormous energy burst—mostly in the form of neutrinos—and could heat and strip some mass from the companion, though both stars would largely survive. Earth’s distance would likely keep the event from being catastrophic, but many details about the system and timing remain uncertain.
A global network of neutrino detectors, including Canada’s SNO+ and China’s JUNO, is measuring geoneutrinos to quantify the heat-producing elements in Earth’s mantle. Early results from SNO+ show western hemisphere fluxes that hint at mantle heterogeneity linked to deep structures like large low-shear-velocity provinces (LLSVPs), but large uncertainties remain. More data and improved geological modeling, and possibly an ocean-bottom detector, could sharpen the map of the planet’s interior heat sources.
Core-collapse supernovae emit the vast majority of their energy as neutrinos rather than light—about 99% versus 0.1–1% in photons—because electron capture in the collapsing core produces neutrinos that escape with little interaction. This neutrino burst powers the explosion and confirms the energy budget, as demonstrated by SN 1987A's detections; with detectors like Hyper-Kamiokande and IceCube, a future galactic SN would yield millions of neutrinos, making neutrinos the primary energy carrier in these events.
Eight minutes after leaving the Sun’s surface, sunlight reaches Earth, but the energy inside each photon spent 10,000–170,000 years zigzagging through the Sun’s dense core via countless absorption-and-reemission events; neutrinos escape in about two seconds, revealing the core’s workings, while the outer radiative and convective zones, and the photosphere, shape the final journey of energy to us.
Researchers analyzing 14 years of data from the Super-Kamiokande detector report a likely signal of the Diffuse Supernova Neutrino Background—the universe’s background of neutrinos from all past core-collapse supernovas—marking a potential first detection of these cosmic 'ghost' particles; if confirmed, it would illuminate how dying stars enrich their environments and form compact remnants, with plans to combine data with Hyper-Kamiokande to boost sensitivity.
Avi Loeb explains that neutrinos from Galactic supernovae penetrate interstellar dust and reveal explosions that optical observations often miss. The 1987 SN 1987A produced 24 neutrinos detected by Kamiokande-II, IMB, and Baksan, enabling estimates of the explosion’s energy and the newborn neutron star’s properties. Today’s and forthcoming detectors—Super-Kamiokande, JUNO, IceCube, Hyper-Kamiokande, and DUNE—could observe thousands to tens of thousands of events from a Milky Way supernova, allowing measurements of neutrino masses and oscillations as well as the neutron star’s mass, radius, and binding energy. Webb’s 2022 observations of a neutron-star signature in SN 1987A underscore the potential of neutrino astronomy for probing fundamental physics and stellar remnants.
During a 2018 calibration, the SNO+ detector buried deep underground in Ontario used ultrapure water to detect inverse beta decay from antineutrinos emitted by a nuclear reactor over 240 kilometers away, with 99.7% confidence that the signal was reactor-related. The finding shows that plain water can be used to monitor distant reactors via antineutrinos and opens the door to cheaper, safer neutrino-detection methods, while contributing to fundamental neutrino physics.
Scientists at the SNO+ underground lab detected inverse beta decay signals from antineutrinos emitted by a nuclear reactor roughly 240 km away using ultrapure water in a large tank, marking the first time water alone captured such low-energy events (down to 1.4 MeV). An analysis of 190 days of calibration data yielded a 3-sigma candidate signal, suggesting plain water could someday be used to monitor reactor output at a distance and demonstrating a cheaper path for neutrino detection.
A high-energy neutrino detected by IceCube may have originated from Shadow Blaster, a dust-enshrouded, intensely star-forming galaxy 11 billion light-years away that is gravitationally lensed. This link, while tentative (about 1% chance of a random coincidence), suggests star-forming galaxies could contribute a significant fraction of the diffuse neutrino background, and motivates deeper multiwavelength follow-up with facilities like ALMA and JWST to pinpoint more such sources.
Physicists have built some of the world’s most ambitious detectors—buried underground, underwater, and under Antarctic ice—to catch neutrinos, elusive particles that rarely interact with matter. From Pauli’s proposal and the first detection in the 1950s to solar-neutrino puzzles and modern observatories like Kamiokande, Super-Kamiokande, SNO, IceCube, KM3NeT, JUNO, DUNE, and Hyper-K, the field has shown neutrinos come in flavors that oscillate due to mass, guiding experimental design and enabling study of stars, the cosmos, and fundamental physics.
Astronomers using the Atacama Cosmology Telescope have produced the clearest image yet of the cosmic microwave background, revealing light from about 380,000 years after the Big Bang and mapping tiny temperature fluctuations that seeded the formation of galaxies. The improved data tighten constraints on cosmological parameters, including neutrino masses, and set the stage for future polarization measurements with the Simons Observatory, as researchers seek to connect early-Universe physics with observations of the modern cosmos.