Cosmic Rays Research Articles

Quantifying the High Early Solar Cosmic-Ray Flux with Cosmogenic Neon Isotopes in Refractory Minerals

An enhancement in the activity of the early young Sun resulting in a high charged particle flux has been invoked to explain excesses in spallation-induced nuclides in primitive planetary materials. Astronomical observations of energetic outbursts of young stellar objects (YSOs) also support the idea of an active young Sun. However, the early solar cosmic-ray (SCR) flux has not been well constrained. Here we use measured concentrations of SCR-produced nuclides that formed and are preserved in meteoritical hibonite and spinel, some of the solar system’s oldest solids, and physical models for dust transport in the early protoplanetary disk to determine the magnitude of the early SCR flux. We focus our attention on cosmogenic neon, which cannot have been inherited from precursors and can only be produced in situ in solids. Our modeled effective exposure time to SCRs for these solids is very short, on the order of years. This indicates that the young Sun’s SCR flux recorded in refractory mineral hibonite was up to ∼7 orders of magnitude higher than the contemporary level. Our flux estimate is consistent with the >105× enhanced flux inferred from astronomical observations of greatly enhanced flare activities of YSOs.

Effect of solar wind disturbances on small-amplitude simultaneous Forbush events during solar cycle 23

The transient and rapid reduction in galactic cosmic ray (GCR) flux intensity, commonly referred to as Forbush decrease (FD), is widely used as a mediator variable in searching for solar-terrestrial weather linkages. Whereas literature in the field is replete with high-amplitude (FD(%) ⩾3) FD-based analyses, the empirical connections between low-amplitude (FD(%) ⩽3) events and Sun-Earth variables are seldom tested. It is recently observed that the dearth of such studies might be due to the daunting task of accurate detection/precise timing of FDs and other transient astrophysical events. Using a sensitive version of the FD detection algorithm, we selected 264, 267, and 206 low amplitude (FD(%) ⩽3) FDs from the daily GCR data of Hermanus (HRMS), Newark (NWRK) and Oulu (OULU) neutron monitor stations respectively during solar cycle 23. A total of 80 simultaneous small-amplitude FDs were identified from the three stations with a simple coincident computer code. Statistically significant correlations at 95% confidence level exist between the planetary K-index (Kp), disturbance storm time index (Dst), planetary A-index (Ap), and the corresponding simultaneous small-amplitude FDs at OULU station, but not found in HRMS and NWRK data. These significant links between the weak FDs and the geomagnetic indices (Kp, Dst, and Ap) at OULU station suggest that the parameters (Kp, Dst, and Ap) are likely connected with some common solar activities.

Study of solar activities associated with a Halo CME on 17 Feb 2023 event

In the present work, propagation of an earth directed fast and wide Coronal Mass Ejection event on 17 February 2023 is studied in detail. The complex magnetic configuration in the Active Region (AR) 13229 at N25E64 caused an intensive X2.3 flare with a peak at 19:38 UT. It is followed by a massive halo CME event observed in the LASCO C3 coronagraph with a linear speed of 930 km/s and shock speed of 1300 km/s. A low frequency Type II emission was detected in the frequency range 10 MHz – 180 kHz during 20:30 UT-04:45 UT on 18 Feb 2023 by space borne Wind/WAVES instrument. From the OMNI data, the IP shock and the ICME reached earth's magnetosphere on 20 Feb 2023. A fast forward type shock was observed using OMNI high resolution data. The IP shock and ICME affected the Galactic Cosmic ray (GCR) detection. This event caused large magnetic turbulences in sheath region caused a major geomagnetic storm (∼-100 nT).

Turbulent Diffuse Molecular Media with Nonideal Magnetohydrodynamics and Consistent Thermochemistry: Numerical Simulations and Dynamic Characteristics

Turbulent diffuse molecular clouds can exhibit complicated morphologies caused by the interactions among radiation, chemistry, fluids, and fields. We performed full 3D simulations for turbulent diffuse molecular interstellar media, featuring time-dependent nonequilibrium thermochemistry coevolved with magnetohydrodynamics (MHD). Simulation results exhibit the relative abundances of key chemical species (e.g., C, CO, OH) vary by more than one order of magnitude for the “premature” epoch of chemical evolution (t ≲ 2 × 105 yr). Various simulations are also conducted to study the impacts of physical parameters. Nonideal MHD effects are essential in shaping the behavior of gases, and strong magnetic fields (∼10 μG) tend to inhibit vigorous compressions and thus reduce the fraction of warm gases (T ≳ 102 K). Thermodynamical and chemical conditions of the gas are sensitive to modulation by dynamic conditions, especially the energy injection by turbulence. Chemical features, including ionization (cosmic ray and diffuse interstellar radiation), would not directly affect the turbulence power spectra. Nonetheless, their effects are prominent in the distribution profiles of temperatures and gas densities. Comprehensive observations are necessary and useful to eliminate the degeneracies of physical parameters and constrain the properties of diffuse molecular clouds with confidence.

Observational Overview of the May 2024 G5-Level Geomagnetic Storm: From Solar Eruptions to Terrestrial Consequences

This study reports comprehensive observations for the G5-level geomagnetic storm that occurred from May 10 to 12, 2024, the most intense event since the 2003 Halloween storm. The storm was triggered by a series of coronal mass ejections (CMEs) originating from the merging of two active regions 13664/13668, which formed a large and complex photospheric magnetic configuration and produced X-class flares in early May 2024. Among the events, the most significant CME, driven by an X2.2 flare on May 9, caught up with and merged with a preceding slower CME associated with an X-class flare on May 8. These combined CMEs reached 1 AU simultaneously, resulting in an extreme geomagnetic storm. Geostationary satellite observations revealed changes in Earth’s magnetosphere due to solar wind impacts, increased fluxes of high-energy particles, and periodic magnetic field fluctuations accompanied by particle injections. Extreme geomagnetic storms resulting from the interaction of the solar wind with the Earth’s magnetosphere caused significant energy influx into Earth’s upper atmosphere over the polar regions, leading to thermospheric heating and changes in the global atmospheric composition and ionosphere. As part of this global disturbance, significant disruptions were also observed in the East Asian sector, including the Korean Peninsula. Ground-based observations show strong negative storm effects in the ionosphere, which are associated with thermospheric heating and resulting in decreases in the oxygen-to-nitrogen ratio (O/N2) in high-latitude regions. Global responses of storm-time prompt penetration electric fields were also observed from magnetometers over the East-Asian longitudinal sector. We also briefly report storm-time responses of aurora and cosmic rays using all-sky cameras and neutron monitors operated by the Korea Astronomy and Space Science Institute (KASI). The extensive observations of the G5-level storm offer crucial insights into Sun-Earth interactions during extreme space weather events and may help establish better preparation for future space weather challenges.

Maternal and Fetal Health Risks Among Female Military Aviation Officers.

INTRODUCTION: Military aviation poses unique occupational risks, including exposures to intermittent hypoxia, high gravitational force, and toxic materials, in addition to circadian disruption, cosmic radiation, and ergonomic stressors also present in commercial flight. We sought to investigate whether a military aviation officer's career is associated with adverse maternal or fetal health outcomes.METHODS: We conducted a retrospective cohort study of female aviation and nonaviation officers in the Military Health System from October 2002 to December 2019. Exposure was identified as assignment of an aviation occupation code. Maternal and fetal health outcomes were identified by International Classification of Diseases codes from medical records. Regression analysis was used to estimate adjusted relative risks (aRR).RESULTS: Included in the study were 25,929 active-duty female officers, with 46,323 recorded pregnancies and 32,853 recorded deliveries; 2131 pregnancies were diagnosed in aviation officers. Pregnant aviation officers had a decreased risk of composite adverse pregnancy outcomes [aRR 0.82 (0.73-0.92)], including gestational diabetes [aRR 0.69 (0.57-0.85)] and gestational hypertension [aRR 0.84 (0.71-0.99)]. Pregnant aviation officers had a decreased risk of depression prior to delivery [aRR 0.43 (0.35-0.53)] and hyperemesis gravidarum [aRR 0.74 (0.57-0.96)], but an increased risk of placental complications [aRR 1.15 (1.02-1.30)] and fetal growth restriction [aRR 1.36 (1.16-1.60)].DISCUSSION: Pregnant military aviation officers have an increased risk of placental complications and fetal growth restriction in spite of a lower risk of gestational diabetes and gestational hypertension. Further research is needed to determine how flight-related occupations impact pregnancy.Stark CM, Sorensen IS, Royall M, Dorr M, Brown J, Dobson N, Salzman S, Susi A, Hisle-Gorman E, Huggins BH, Nylund CM. Maternal and fetal health risks among female military aviation officers. Aerosp Med Hum Perform. 2024; 95(9):675-682.

Revisit of GeV Gamma-Ray Emission from Orion B with the Fermi Large Area Telescope

We revisit the γ-ray emission above 300 MeV towards the massive star-forming region of Orion B by adopting 14 yr observations with the Fermi Large Area Telescope and utilizing the updated software tools. The extended γ-ray emission region around Orion B is resolved into two components (region I and region II). The γ-ray spectrum of region I agrees with the predicted γ-ray spectrum assuming the cosmic ray (CR) density is the same as that of Alpha Magnetic Spectrometer (AMS-02) measured locally. The γ-ray emissivity of region II appears to be deficit at low energy band (E < 3 GeV). Through modeling we find that CR densities exhibit a significant deficit below 20 GeV, which may be caused by a slow diffusion inside the dense region. This is probably caused by an increased magnetic field whose strength increases with the gas density.

Initial Results of Low Earth Orbit Space Radiation Dosimeter on Board the Next Generation Small Satellite-2

As human exploration goals shift from missions in low Earth orbit (LEO) to long-duration interplanetary missions, radiation protection remains one of the key technological issues that must be resolved. The low Earth orbit space radiation dosimeter (LEO-DOS) instrument to measure radiation levels and create a global dose map in the LEO on board the the next generation small satellite-2 (NEXTSat-2) was launched successfully on May 25, 2023 using the Nuri KSLV-III in Korea. The NEXTSat-2 orbits the Earth every 100 minutes, in an orbit with an inclination of 97.8° and an altitude of about 550 km above sea level. The LEO-DOS is equipped with a particle dosimeter (PD) and a neutron spectrometer (NS), which enable the measurement of dosimetric quantities such as absorbed dose (D), dose equivalent (H) for charged particles and neutrons. To verify the observations of LEO-DOS, we conducted a radiation dose estimation study based on the initial results of LEO-DOS, measured from June 2023 to September 2023. The study considered four source categories: (i) galactic cosmic ray particles; (ii) the South Atlantic Anomaly region of the inner radiation belt (IRB); (iii) relativistic electrons and/or bremsstrahlung in the outer radiation belt (ORB); and (iv) solar energetic particle (SEP) events.

Irregularity in the Primary Cosmic Rays Mass Composition at an Energy of ~10 PeV

Irregularity in the Primary Cosmic Rays Mass Composition at an Energy of ~10 PeV

Very High Energy Solar Energetic Particle Events and Ground Level Enhancement Events: Forecasting and Alerts

AbstractA Ground Level Enhancement (GLE) event can be observed as an increase in the background of ground‐based neutron monitor observations and is often associated with an increase of &gt;500 MeV space‐based proton flux measurements. GLE events begin as very high‐energy SEP events associated with GeV protons. For such events to be detected at sea level, proton energies must exceed about 433 MeV. Since the increased flux of such particles can be a major problem to technology in space and on Earth and pose a threat for human health, developing real time warning systems is of great importance. GLE Alert++ is a product, built by the Athens Cosmic Ray Group of the National and Kapodistrian University of Athens, that issues alerts when a GLE event starts to register and is based on ground‐based neutron monitor observations. From the space‐based approach, the HESPERIA UMASEP‐500 product, jointly developed within the framework of the EU HORIZON2020 HESPERIA project by the Universidad de Malaga, Spain and National Observatory of Athens, Greece, provides forecasts of GLE events and &gt;500 MeV protons relying on GOES satellite Soft X‐Ray and high energy proton observations. These two products are fully integrated as federated products on the ESA SWE Portal and are provided as part of the ESA Space Safety Program Space Weather Service Network. In this paper we present how the products were built, provide examples of their outputs as seen on the ESA SWE Portal, and show how the products complement each other and how using them together can in some instances provide more information for users of these services.

Search for MeV gamma-ray emission from TeV bright red dwarfs with COMPTEL

The SHALON atmospheric Cherenkov telescope has detected very high energy gamma-ray emission at TeV energies from eight red dwarfs, namely, V388 Cas, V547 Cas, V780 Tau, V962 Tau, V1589 Cyg, GJ 1078, GJ 3684 and GL 851.1. Consequently, these red dwarfs have been suggested as sources of ultra-high energy cosmic rays. In this work, we search for soft gamma-ray emission from these TeV bright red dwarfs between 0.75–30 MeV using archival data from the COMPTEL gamma-ray imaging telescope, as a follow-up to a similar search for GeV gamma-ray emission using the Fermi-LAT telescope. Although, prima-facie, we detect non-zero photon flux from three red dwarfs with high significance, these signals can attributed to contamination from nearby sources such as Crab and Cygnus, which are within the angular resolution of COMPTEL, and have been previously detected as very bright point sources at MeV energies. Therefore, we could not detect any statistically significant signal (> 3σ) from any of these eight red dwarfs from 0.75–30 MeV. We then report the 95% confidence level upper limits on the differential photon flux (at 30 MeV), integral photon flux and integral energy flux for all of the eight red dwarfs. The integral energy flux limits range between 10-11 - 10-10-ergs/cm2/s.

Abatement of ionizing radiation for superconducting quantum devices

Ionizing radiation has been shown to reduce the performance of superconducting quantum circuits. In this report, we evaluate the expected contributions of different sources of ambient radioactivity for typical superconducting qubit experiment platforms. Our assessment of radioactivity inside a typical cryostat highlights the importance of selecting appropriate materials for the experiment components nearest to qubit devices, such as packaging and electrical interconnects. We present a shallow underground facility (30-meter water equivalent) to reduce the flux of cosmic rays and a lead shielded cryostat to abate the naturally occurring radiogenic gamma-ray flux in the laboratory environment. We predict that superconducting qubit devices operated in this facility could experience a reduced rate of correlated multi-qubit errors by a factor of approximately 20 relative to the rate in a typical above-ground, unshielded facility. Finally, we outline overall design improvements that would be required to further reduce the residual ionizing radiation rate, down to the limit of current generation direct detection dark matter experiments.

Results of the follow-up of ANTARES neutrino alerts

High-energy neutrinos could be produced in the interaction of charged cosmic rays with matter or radiation surrounding astrophysical sources. To look for transient sources associated with neutrino emission, a follow-up program of neutrino alerts has been operating within the ANTARES collaboration since 2009. This program, named TAToO, has triggered robotic optical telescopes (MASTER, TAROT, ROTSE and the SVOM ground based telescopes) immediately after the detection of any relevant neutrino candidate and scheduled several observations in the weeks following the detection. A subset of ANTARES events with highest probabilities of being of cosmic origin has also been followed by the Swift and the INTEGRAL satellites, the Murchison Widefield Array radio telescope and the H.E.S.S. high-energy gamma-ray telescope. The results of twelve years of observations are reported. In September 2015, ANTARES issued a neutrino alert and during the follow-up, a potential transient counterpart was identified by Swift and MASTER. A multi-wavelength follow-up campaign has allowed to identify the nature of this source and has proven its fortuitous association with the neutrino. No other optical and X-ray counterpart has been significantly associated with an ANTARES candidate neutrino signal. Constraints on transient neutrino emission have been set. The return of experience is particularly important for the design of the alert system of KM3NeT, the next generation neutrino telescope in the Mediterranean Sea.

HESS J1745−290 spectrum explained by a transition in the diffusion regime of PeV cosmic rays in the Sgr A* accretion flow

HESS J1745−290 spectrum explained by a transition in the diffusion regime of PeV cosmic rays in the Sgr A* accretion flow

Piceatannol reduces radiation-induced DNA double-strand breaks by suppressing superoxide production and enhancing ATM-dependent repair efficiency

In contemporary society, humans are susceptible to various radiation-borne hazards, including exposure to therapeutic modalities using low-linear energy transfer (low-LET) radiations (X-rays and γ-rays), natural high-LET radiation sourced from cosmic rays, as well as nuclear accidents such as the Fukushima Daiichi Nuclear Power Plant incident. Therefore, this threat incites an imminent necessity to develop novel radioprotective agents against a wide range of LET radiation and elucidate the underlying molecular mechanisms. This study aimed at assessing the radioprotectivity of Piceatannol (PIC), a potent antioxidant polyphenol present in abundance in passion fruit, by investigating its effects on radiation-induced reactive oxygen species (ROS) production and the consequent DNA double-strand break (DSB) capacity and cellular senescence. Specifically, total ROS was evaluated by DCFDA staining, mitochondrial superoxide by MitoSOX staining, DSB by γ-H2AX immunostaining, and cellular senescence by Senescence-associated-β-galactosidase staining.The results demonstrated that PIC administration prior to exposure to both X-ray and high-LET radiation impeded radiation-induced DSB by suppressing ROS production. Interestingly, post-irradiation PIC treatment did not alter ROS levels but enhanced the efficiency of Ataxia Telangiectasia Mutated (ATM)-mediated DSB repair. Additionally, post-irradiation PIC treatment diminished senescence-associated beta-galactosidase levels, indicating that it hinders cellular senescence.Conclusively, PIC exerts radioprotective effects against a wide range of LET radiation. The study findings validate the potential application of PIC not only as a radical scavenger but also as a novel DSB repair-activating radioprotective agent.

POEMMA-Balloon with Radio: A balloon-born multi-messenger multi-detector observatory

The Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) is a proposed dual-satellite mission to observe Ultra-High-Energy Cosmic Rays (UHECRs), increasing the statistics at the highest energies, and Very-High-Energy Neutrinos (VHENs), following multi-messenger alerts of astrophysical transient events throughout the universe such as gamma-ray bursts and gravitational wave events. POEMMA-Balloon with Radio (PBR) is a scaled-down version of the POEMMA design, adapted to be flown as a payload on one of NASA’s sub-orbital Super Pressure Balloons (SPBs) circling over the Southern Ocean for up to 100 days after a launch from Wanaka, New Zealand. This overview will provide a summary of the mission with its science goals, the instruments, and the current status of PBR.

Petrology and chronology of mare components in lunar basaltic breccia meteorite Northwest Africa 12384

AbstractNorthwest Africa (NWA) 12384 is a lunar polymict breccia composed almost entirely of basaltic components. The clast content includes low‐ to very‐low‐Ti volcanic picritic glass, basaltic vitrophyre, and crystalline pigeonite basalt—an assemblage of volcanic materials that can be tested for petrogenetic relationships. We present the inferred history of select mare components of NWA 12384 as suggested by texture, mineralogy, and petrography, and compare them to Apollo samples and other lunar meteorites. In addition, we used the volcanic glasses in the breccia as a primary composition for crystallization modeling and comparison to the lithic clast compositions. We find that the mafic clasts in NWA 12384 cannot be derived from the picritic glass through a common liquid line of descent because of higher Ti content, though they may have crystallized from a separate, common liquid line of descent. These clasts could represent local source‐region heterogeneity or differential assimilation of more Ti‐rich material. Pb‐Pb SIMS analyses of a large basalt clast in NWA 12384 reveal an age of 3044 ± 41 Ma (2σ), which is used together with the chemical data and 4π cosmic ray exposure age of less than 20 kyr and terrestrial age of between 3.1 and 17.3 kyr to constrain the possible locations of provenance for this meteorite.

Cognitive Effects of Simulated Galactic Cosmic Radiation Are Mediated by ApoE Status, Sex, and Environment in APP Knock-In Mice.

Cosmic radiation experienced during space travel may increase the risk of cognitive impairment. While simulated galactic cosmic radiation (GCRsim) has led to memory deficits in wildtype (WT) mice, it has not been investigated whether GCRsim in combination with genetic risk factors for Alzheimer's disease (AD) worsens memory further in aging mice. Here, we investigated the central nervous system (CNS) effects of 0 Gy (sham) or 0.75 Gy five-ion GCRsim or 2 Gy gamma radiation (IRR) in 14-month-old female and male APPNL-F/NL-F knock-in (KI) mice bearing humanized ApoE3 or ApoE4 (APP;E3F and APP;E4F). As travel to a specialized facility was required for irradiation, both traveled sham-irradiated C57BL/6J WT and KI mice and non-traveled (NT) KI mice acted as controls for potential effects of travel. Mice underwent four behavioral tests at 20 months of age and were euthanized for pathological and biochemical analyses 1 month later. Fecal samples were collected pre- and post-irradiation at four different time points. GCRsim seemed to impair memory in male APP;E3F mice compared to their sham counterparts. Travel tended to improve cognition in male APP;E3F mice and lowered total Aβ in female and male APP;E3F mice compared to their non-traveled counterparts. Sham-irradiated male APP;E4F mice accumulated more fibrillar amyloid than their APP;E3F counterparts. Radiation exposure had only modest effects on behavior and brain changes, but travel-, sex-, and genotype-specific effects were seen. Irradiated mice had immediate and long-term differences in their gut bacterial composition that correlated to Alzheimer's disease phenotypes.

Testing unified models for the origin of ultrahigh-energy cosmic rays and neutrinos: Multimessenger approaches with x-ray observations

Testing unified models for the origin of ultrahigh-energy cosmic rays and neutrinos: Multimessenger approaches with x-ray observations

First Results of the CREDO-Maze Cosmic Ray Project

The CREDO-Maze project is the concept for a network of stations recording local, extensive cosmic ray air showers. Each station consists of four small scintillation detectors and a control unit that monitors the cosmic ray flux 24 h a day and transmits the results to the central server. The modular design of each array allows the results to be used in educational classes on nuclear radiation, relativistic physics, and particle physics and as a teaching aid in regular school classrooms and more. As an example, we present here some preliminary results from the CREDO-Maze muon telescope missions to the Arctic and down into a deep salt mine, as well as the first shower-particle correlation measurements from a table-top experiment at Walailak University. These experiments show that the different geometric configurations of the CREDO-Maze detector set can be used for projects beyond the scope of the secondary school curriculum, and they can form the basis of student theses and dissertations at universities.