The Baikal Gigaton Volume Detector is a neutrino telescope currently under construction in Lake Baikal. The main goal of Baikal-GVD is to detect high-evergy cosmic neutrinos using both track-like and cascade-like events. Baikal-GVD has been following the IceCube telescope neutrino alerts since September 2020. The prompt real-time response (the delay is ~ 3 min) to these alerts is complemented...
Gamma-Ray Bursts (GRBs) are considered promising neutrino emitters. They appear as extremely intense bursts of gamma-ray radiation of extragalactic origin observed isotropically in the sky and constitute the most powerful explosions observable in the Universe. A lot has been learnt about these sources in the last years, however their jet composition remains still an open issue. Within the...
The main aim of the Baikal-GVD (Gigaton Volume Detector) neutrino telescope is to detect high energy astrophysical neutrinos and to identify their sources on the sky. The Baikal-GVD is located at a depth of 1366 metres in Lake Baikal. Currently (year 2022), it is composed of 10 functionally independent units, referred to as clusters, that comprise 2880 optical modules (OMs) in total. OMs are...
IceCube-Gen2-Optical is a planned large-scale upgrade to the existing IceCube Neutrino Observatory. This ~8 cubic kilometer in-ice detector is optimized for point-source science, yielding integer-factor improvements to angular resolution, and increased sensitivity to higher energies. Here, impact on future study of the diffuse astrophysical spectrum is presented. New analyses of upgoing muon...
In the ultra-high energy regime, the low predicted neutrino fluxes are out of reach for currently running neutrino detectors. Larger instrumented volumes are needed to probe these low fluxes. The Radio Neutrino Observatory Greenland (RNO-G) detects radio waves emitted by neutrino induced particle showers in the Greenlandic ice sheet. Radio waves have a large attenuation length in ice (O(1km))...
Starburst galaxies (SBGs) and more in general starforming galaxies represent a class of galaxies with a high star formation rate (up to 100 Mo/year). Despite their low luminosity, they can be considered as guaranteed “factories” of high energy neutrinos, being “reservoirs” of accelerated cosmic rays and hosting a high density target gas in the central region. The estimation of their point-like...
After entering the Galactic cosmic rays (GCRs) into the heliosphere, their intensities decrease during their propagation toward the Earth. This effect is subjected to a variety of physical processes through their propagation which is referred to as CR solar modulation. The key ingredients in the study of this phenomenon are the knowledge of the local interstellar spectrum (LIS) of Galactic...
Similarly to the geomagnetic cutoff, which is the lower energy (magnetic rigidity) limit for particles that are able to pass the geomagnetic field and reach the Earth's atmosphere, there is the atmospheric cutoff. It represents the lower limit in energy for cosmic-ray particles propagating in the atmosphere and which can be registered on the ground by, e.g., neutron monitors. The atmospheric...
Coronal mass ejections (CMEs), interplanetary shocks, and corotating interaction regions (CIRs) drive heliospheric variability, causing various interplanetary as well as planetary disturbances. One of their very common in-situ signatures are short-term reductions in the galactic cosmic ray (GCR) flux (i.e. Forbush decreases), which are measured by ground-based instruments at Earth and Mars, as...
There are currently multiple available neutron monitor (NM) databases which host and distribute measurements of the total of 147 NM stations. These databases include the World Data Center for Cosmic Rays (WDCCR), the Neutron Monitor Database (NMDB), the Pushkov Institute of Terrestrial Magnetism, Ionosphere, and Radiowave Propagation (IZMIRAN) and individual station/institution...
We study the 27-day variations of galactic cosmic rays (GCRs) based on neutron monitor (NM), ACE/CRIS, STEREO and SOHO/EPHIN measurements, in solar minima 23/24 and 24/25 characterized by the opposite polarities of solar magnetic cycle. Now there is an opportunity to reanalyze the polarity dependence of the amplitudes of the recurrent GCR variations in 2007-2009 for negative A < 0 solar...
The first solar proton event of solar cycle 25 was detected on 28 October 2021 by several neutron monitors (NMs) in the polar region as well as the fleet of space-borne instruments. It is identified as the GLE (ground-level enhancement) #73 in the International GLE database, with the strongest signal registered by the DOMC/DOMB monitors located at the Antarctic plateau at the Concordia...
Since its launch, the Alpha Magnetic Spectrometer-02 (AMS-02) has delivered outstanding quality measurements of the spectra of cosmic-ray (CR) species (p¯, e±) and nuclei (H–Si, Fe), which resulted in a number of breakthroughs. Spectra of heavier low-abundance nuclei are not expected until later in the mission. Consequently, we exploited a “fraction” of HEAO-3-C2 data that match available...
Young massive stellar clusters are increasingly discussed as major contributors to the flux of Galactic cosmic rays. Westerlund 1, being the most massive young stellar cluster in the Milky Way, is a prime target to study in this regard. We present results from deep observations of the region around Westerlund 1 in very-high-energy gamma rays with the H.E.S.S. array of Cherenkov telescopes. We...
Andes Large area PArticle detector for Cosmic ray physics and Astronomy (ALPACA) is an air shower array experiment aiming to observe cosmic rays and gamma-rays in the southern hemisphere. The array will cover an 83,000$\rm{m^{2}}$ surface area with 400 scintillating plastic counters at the plateau (4,740m a.s.l.) of the Chacaltaya mountain in Bolivia. Underground muon detectors covering 3,700...
The radio-quiet gamma-ray pulsar PSR J2021+4026, in the Gamma Cygni supernova remnant, is one of the brightest Fermi-LAT pulsars. It first drew attentions in October 2011, when it underwent an abrupt drop in its gamma-ray flux, with a simultaneous increase in its spin-down rate. This mode change was followed by a smooth recovery phase around December 2014, then by a similar mode change in...
MAGIC is a system of two Imaging Atmospheric Cherenkov telescopes, in operation since 2009 at the Observatorio del Roque de los Muchachos, in La Palma (Canary Islands, Spain). MAGIC is sensitive to photons in the energy band between few tens of GeV and few tens of TeV: the so-called very-high-energy gamma rays. In this talk, I present a selection of recent scientific highlights involving the...
HESS J1843-033 is an unidentified TeV gamma-ray source reported by H.E.S.S. Galactic Plane Survey (Hoppe, ICRC2008, H.E.S.S. Collaboration, A&A 612, A1, 2018). In the adjacent region, HAWC and LHAASO also discovered high-energy gamma-ray sources (Abeysekara et al., PRL 124, 021102, 2020; Cao et al., Nature 594, 33, 2021), but their origins remain unclear, and the relation of these gamma-ray...
A ground-level enhancement (GLE) is defined as a strong event with high-energy solar energetic particles (SEPs) detected by the network of ground-based neutron monitors. Until now, 73 GLEs have been registered. In this work, we report a new reconstruction of the event-integrated spectra (fluences) of SEPs during 59 moderate and strong GLE events detected by NM network and satellite...
The precision measurement of daily proton fluxes with AMS during ten years of operation in the rigidity interval from 1 to 100 GV is presented. The proton fluxes exhibit variations on multiple time scales. From 2014 to 2018, we observed recurrent flux variations with a period of 27 days. Shorter periods of 9 days and 13.5 days are observed in 2016. The strength of all three periodicities...
After more than a century of discovering cosmic rays, a comprehensive description of their origin, propagation, and composition still eludes us. One of the difficulties is that these particles interact with magnetic fields; therefore, their directional information is distorted as they travel. In addition, as cosmic rays (CRs) propagate in the Galaxy, they can be affected by magnetic structures...
The detailed measurement of the daily electron fluxes from May 20, 2011 to October 29, 2019 with the Alpha Magnetic Spectrometer on the International Space Station, is presented. Time variation of the fluxes on different time scales associated with the solar activity over half solar cycle 24 is shown. In addition, the comparison between the time variation of daily electron, positron and proton...
The appropriate knowledge and forecasting of cosmic ion radiation experienced by spacecrafts at Earth location and by interplanetary probes during their transfer orbit is a piece of relevant information, especially for what concerns the estimation of the radiation hazard in electronic devices. The HelMod Model evaluates the solar modulation effect on local interstellar spectra of galactic...
Thermal electrons cannot directly participate in the process of diffusive acceleration at electron-ion shocks because their Larmor radii are smaller than the shock transition width: this is the well-known electron injection problem of diffusive shock acceleration. Instead, an efficient pre-acceleration process must exist that scatters electrons off of electromagnetic fluctuations on scales...
The flux of solar energetic particles (SEPs) varies at different time scales, from minutes to the 11-year solar cycle, forming an important highly variable radiation factor near Earth. However, measurements of the SEP flux are subject to large uncertainties as assessed by different methods and from different instruments. Here we report the results of a revision of annual integral SEP fluences...
Last decade the research in high-energy physics in the atmosphere (HEAP) was mostly concentrated on measuring the particle fluxes from the electrified atmosphere (thunderstorm ground enhancements, TGEs, and Terrestrial gamma flashes, TGFs) and revealing their origin. Afterward, in 2021 started the research of the atmospheric electric fields using particle fluxes traversing thunderstorms and...
This work represents the research related to the modeling of cosmic rays propagation through the Earth atmosphere and calculation of the specific yield function in form of ionization profiles at different depths (altitudes). The simulation have been performed with the Monte-Carlo based GEANT4 software development toolkit, which includes the cascade models, the neutron interaction databases,...
Cosmic gamma ray bursts(GRB) are high energetic photos resulting from astrophysical events within and beyond our galaxy. Their energy is deposited in the upper atmosphere by ionization of the constituent atoms and molecules. The resulting plasma affects the absorption and hence the propagation of radio waves in the VLF range which can be used to detect and analyze GRB. In this work we are...
The Tibet air shower array is located at 4,300m above sea level, Tibet, China. It is an international joint project between China and Japan. The Tibet air shower array which observes high-energy cosmic rays above 3 TeV. The Sun casts a shadow in high-energy cosmic-ray intensity observed at the Earth and the depth and location of the shadow vary according to variations of the solar magnetic...
The Global Cosmic Rays Observatory is a proposal for a new large-scale observatory to measure the properties of ultra-high energy cosmic rays. To discuss this proposal the first workshop, gathering more than 200 scientists, was followed by a meeting in July 2022 when a more detailed science case and detector design have been discussed. Several questions paved the way of discussions: In ten...
The High Energy cosmic-Radiation Detection (HERD) facility is a future experiment that will be installed aboard the China’s Space Station around 2027. Using a single instrument, the experiment aims to perform high energy measurements relative to cosmic ray, gamma astronomy and indirect dark matter search. This is possible thanks to the innovative design based on a homogeneous, isotropic and 3D...
The observation of PeV cosmic rays is essential to solving the question on the origin of cosmic rays, but because these are affected by magnetic fields, $\gamma$-rays at the sub-PeV scale emerge as a better tool to search for sources in our galaxy.
In $2019$ the Tibet AS$\gamma$ collaboration reported the detection of sub-PeV $\gamma$-rays coming from the Crab nebula using a novel technique...
Over the last couple of years, particle detectors at high elevation sites provided a fresh look at the gamma-ray sky. Observatories, like HAWC, and more recently LHAASO, have significantly increased the number of TeV observed gamma-ray sources and opened up a new energy regime in astronomy. Several astrophysical objects are now confirmed to emit significantly above 100 TeV photon energy,...
Context. The Southern Wide-field Gamma-ray Observatory (SWGO) is an international collaboration working on realizing a next-generation observatory located in the Southern hemisphere, which offers a privileged view of our galactic center.
Aims. Istituto Nazionale di Fisica Nucleare (INFN) is working on the construction of a prototype water Cherenkov detector at Politecnico di Milano using...
The Cosmic Ray Energetics And Mass (CREAM) experiment was developed to measure the cosmic ray elemental spectra for Z=1-26 nuclei at energies ranging from $\sim {10}^{12}$ to $\sim {10}^{15}$ eV. The balloon-borne CREAM had 7 successful flights over Antarctica and it was recently installed on the International Space Station. For energy measurements, the CREAM instrument uses a calorimeter...
The General Antiparticle Spectrometer (GAPS) Antarctic long duration balloon mission is the first experiment optimized for the detection of low-energy cosmic antinuclei. Its novel detection technique is based on exotic atom formation, excitation, and decay, and aims to place world leading limits on viable dark matter models and inform existing models of cosmic ray propagation. There are two...
The last decade has been marked by significant progress in searches for antimatter in cosmic-rays. The unexpected abundance of positrons in the energy interval 10-200 GeV, reported by the PAMELA collaboration in 2009 and later confirmed and measured up to 1 TeV by AMS-02, remains unexplained, with nearby astrophysical sources and Dark Matter annihilation invoked as possible explanations. Even...
TeV halos have become a new class of astrophysical objects which were not predicted before their recent observation. They offer evidence that diffusion around sources (concretely, pulsars) is not compatible with the effective average diffusion that our models predict for the Galaxy. This directly impacts Galaxy formation, our knowledge of the propagation process throughout the Galaxy and our...
The Tibet ASgamma and LHAASO collaborations recently reported the observation of a gamma-ray diffuse emission from the Galactic plane with energy up to the PeV.
We show that under physically motivated conditions these results, together with those of Fermi-LAT and ARGO-YBJ at lower energies, can consistently be interpreted in terms of an emission originated by the Galactic cosmic-ray (CR)...
High performant shower discriminators are crucial in the pursuit of PeVatron gamma-ray events. In this contribution, we introduce a novel gamma/hadron discriminating variable that quantifies the azimuthal non-uniformity of the particle distributions at the ground.
The proposed quantity has been tested for showers with energies between $10\,$TeV and $1\,$PeV and detector arrays with different...
Gamma-ray observations by Fermi LAT in nearby clouds have shown that the cosmic-ray flux within 500 pc around the Sun is fairly uniform except in the Eridu cloud, which exhibits a puzzling 30 % drop in gamma-ray emissivity per gas atom. The magnetic field in this filamentary cloud is well aligned with the cloud axis and points towards the halo. In the case of anisotropic diffusion, cosmic rays...
The $\gamma$-ray spectrum of the Galactic source HAWC J1825-134 measured with HAWC [Albert et al., ApJ Lett., 907, L30 (2021)] extends beyond 200 TeV and does not reveal a knee or a cutoff. HAWC J1825-134 is among the best candidates for hadronic PeVatrons --- the objects able to accelerate protons up to the energy of at least 1 PeV. However, this source is situated in a crowded region of the...
The IceCube Neutrino Observatory is a cubic kilometer scale detector deployed
in the Antarctic ice. The surface array of IceCube, IceTop, serves as an
air-shower detector for primary cosmic rays in the PeV energy range and operates
as a veto and calibration detector for the astrophysical neutrino searches
for the IceCube in-ice instrumentation. Enhancing IceTop with a hybrid array
of...
Technological breakthroughs in telescope development have always driven discoveries in astrophysics. Discoveries are yet to be made in the energy band between a few hundreds keV and a few MeV, which is currently very little explored due to the lack of sensitive enough telescopes. In this band the telescope technology is challenged by the changing nature of the photon-matter interaction used to...
The study of how cosmic rays (CRs) interact with the Earth’s magnetic environment is heavily reliant on simulations of CRs trajectories within the Earth’s magnetosphere. These simulations are computationally taxing and require the use of sophisticated programs, with MAGNETOCOSMICS being the most used tool currently. MAGNETOCOSMICS, while functional, fast, and reliable, is outdated (requiring...
NUSES is a new space mission project promoted by the Gran Sasso Science Institute (GSSI) in collaboration with the Italian National Institute of Nuclear Physics (INFN) and Thales Alenia Space Italy (TAS-I), devoted to the exploration of new technologies and observational approaches for space based cosmic ray studies. The mission consists of two detectors operating onboard the NUSES satellite:...
At present time the behavior of electron spectrum at energies more than 1 TeV induce significant interest in view of the contradictory results concerning the presence of the cut-off.
GAMMA-400 gamma-ray telescope with lateral size of calorimetr ~43 Xo will be able to extend the measurements of electron fluxes up to 20 TeV and to verify the data of previous experiments at several TeV energies....
The Schwarzschild-Couder Telescope (SCT) is a Medium-Sized Telescope proposed for the Cherenkov Telescope Array (CTA). The first prototype (named pSCT) has been constructed and is being commissioned at the Lawrence Whipple Observatory in Arizona, USA. The SCT is characterized by a dual-mirror optical design to remove the comatic aberrations across its field of view. The pSCT camera is now...
The existence of cosmic accelerators able to emit charged particles up to ZeV energies has been confirmed by the observations made in the last years by experiments such as Auger and Telescope Array. The interaction of such energetic cosmic-rays with gas or low energy photons, surrounding the astrophysical sources or present in the intergalactic medium, guarantee an ultra-high-energy neutrino...
