Scientists are investigating the potential source of a recently detected ultra-high energy neutrino, KM3-230213A, observed by the KM3NeT Collaboration. Mainak Mukhopadhyay from Fermi National Accelerator Laboratory and Kavli Institute for Cosmological Physics, alongside Shigeo S. Kimura from Tohoku University, and et al., present detailed modelling of pulsar-powered optical transients, including supernovae, super-luminous supernovae, and luminous fast blue optical transients, to determine if they could generate the observed neutrino flux. Their research, which explores the relationship between magnetic field strength, spin period, and transient characteristics, suggests that a population of luminous fast blue optical transients plausibly explains the KM3NeT event, positioning these transients as significant candidates in the search for sources of high and ultra-high energy neutrinos.
The research focused on ordinary supernovae, super-luminous supernovae, and luminous fast blue optical transients, all featuring a newly formed magnetar as the central engine.
Researchers explored both thermal electromagnetic and non-thermal neutrino emission from these sources to determine their potential contribution to the observed neutrino flux. The team scanned a parameter space defined by dipolar magnetic field strength and initial spin period to characterise optical emission properties and lightcurve timescales of these transients.
This scan aimed to identify which transient classes could reproduce the necessary diffuse flux level and neutrino energies required to explain the KM3NeT event. By combining these results, the study concludes that a diffuse neutrino flux originating from a population of luminous fast blue optical transients provides a plausible explanation for the detected signal.
This work establishes that pulsar-powered optical transients are promising sources for current and future high-energy and ultra-high energy neutrino telescopes. The detected event, KM3-230213A, registered a muon energy of approximately 120+110 −60 PeV, implying a parent neutrino energy of roughly 220 PeV, with error bands ranging from 110, 790 PeV at 68% confidence level and 72 PeV, 2.6 EeV at 90% confidence level.
Assuming an isotropic E−2 neutrino flux, a joint analysis with data from IceCube and Pierre Auger observatories supports the plausibility of this diffuse flux normalization. Researchers considered the rotational energy of approximately 2×1052 erg, dependent on the initial spin period and dipolar magnetic field, as a key energy reservoir powering these transients.
They investigated how this energy, combined with the spindown timescale, influences the optical lightcurve evolution and neutrino production mechanisms, including hadronuclear and photohadronic interactions. The study focused on populations of ordinary supernovae, super-luminous supernovae, and luminous fast blue optical transients, each powered by a newly formed magnetar.
Researchers explored both thermal electromagnetic and non-thermal neutrino emission mechanisms from these sources to understand their potential contributions to the observed neutrino flux. To characterise these transients, the team scanned a parameter space defined by the dipolar magnetic field strength and initial spin period.
This scan determined characteristic optical emission properties and lightcurve timescales for each transient class. The research identified which transients could reproduce the required diffuse flux level and neutrino energies necessary to explain the KM3NeT event. Combining these results, scientists concluded that a diffuse neutrino flux originating from luminous fast blue optical transients provides a plausible explanation for the observed signal.
Experiments employed a model of the central engine powering the optical transients and its surrounding environment. The team calculated rotational energies, assuming dipolar magnetic fields ranging from 1013 to 1015 Gauss and initial spin periods between 1 and 10 milliseconds. This approach enabled the determination of spindown timescales, crucial for understanding the evolution of optical lightcurves.
Researchers then modelled UHECR production via hadronuclear and photohadronic interactions, predicting emission timescales ranging from days to months post-collapse, dependent on ejecta properties. The study pioneered a detailed parameter space survey, exploring the relationship between pulsar properties and neutrino emission.
This method achieves a precise connection between the characteristics of optical transients and their potential as sources of ultra-high energy neutrinos. The research focused on populations of ordinary supernovae, super-luminous supernovae, and luminous fast blue optical transients, all featuring a newly formed magnetar as the central engine.
Experiments explored both thermal electromagnetic and non-thermal neutrino emission mechanisms from these sources, scanning parameters of dipolar magnetic field strength and initial spin period to characterise optical emission and lightcurve timescales. The team measured characteristic optical emission properties and lightcurve timescales by scanning the parameter space of the dipolar magnetic field strength and initial spin period.
Results demonstrate that luminous fast blue optical transients can reproduce the required diffuse flux level and neutrino energies, suggesting they are promising sources for high-energy and ultra-high energy neutrinos. Combining these findings, the study concludes that a diffuse neutrino flux originating from a population of LFBOTs plausibly explains the KM3NeT event.
The reconstructed energy of the muon associated with the track topology was estimated to be 120+110 −60 PeV at 68% confidence level. This implies a parent neutrino energy of roughly 220 PeV, with error bands ranging from 110, 790 PeV at 68% and 72 PeV, 2.6 EeV at 90% confidence level. Assuming an isotropic E−2 neutrino flux, a joint fit to the KM3NeT event and non-observations from IceCube and Pierre Auger observatories provides a diffuse flux normalization reconciling the KM3NeT event with existing data.
Data shows that the rotational energy of these pulsars, approximately 2×1052 erg (Pi/1ms)−2, serves as a powerful energy reservoir. The spindown timescale, calculated as 5.6 × 105s (Bd/1014G)−2(Pi/3ms)2, governs the optical lightcurve evolution. Tests prove that LFBOTs, with their powerful central engines and low-mass ejecta, may produce intense, short-lived neutrino signals, making them ideally suited to produce the observed neutrino energy and fluence. This work identifies LFBOTs as a plausible explanation for the KM3-230213A event and supports ongoing searches for ultra-high energy neutrinos.
Luminous fast blue optical transients explain ultra-high energy neutrino detection potentially
Scientists have investigated the potential origin of a recently detected ultra-high energy neutrino event, KM3-230213A, proposing that it could stem from the diffuse neutrino flux generated by pulsar-powered optical transients. The research focused on three types of core-collapse transients, ordinary supernovae, super-luminous supernovae, and luminous fast blue optical transients, examining their capacity to produce high-energy neutrino signatures.
By scanning parameters related to the central engine’s magnetic field strength and initial spin period, researchers determined characteristic optical emission properties and lightcurve timescales for each transient class. The findings suggest that a diffuse neutrino flux originating from a population of luminous fast blue optical transients can adequately explain the KM3NeT event, reconciling it with existing limits from the IceCube and Pierre Auger observatories.
This work establishes that these transients are promising sources for current and future high and ultra-high energy neutrino detection. The authors acknowledge limitations stemming from modeling uncertainties, noting that both ordinary supernovae and super-luminous supernovae could also contribute to the diffuse flux.
Future research will benefit from improved data from optical observatories like the Vera C. Rubin Observatory’s Legacy Survey of Space and Time, alongside enhanced statistics from upcoming ultra-high energy neutrino observatories such as RNO-G and IceCube-Gen2, potentially allowing for definitive answers through stacking searches.
👉 More information
🗞 High energy neutrinos from pulsar-powered optical transients: LFBOTs as potential origin of the KM3NeT event KM3-230213A
🧠ArXiv: https://arxiv.org/abs/2601.22266