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The purpose of this work is to estimate if, among the blazars not detected by the Fermi –LAT, a population of TeV emitting sources could be detected by current or future Cherenkov telescopes. We cross-matched the 5BZCAT catalog of blazars with the most recent X-ray catalogs of point-like sources. Finally, we studied the sources without a 4FGL-DR4 (Fourth catalog of Fermi Gamma-ray LAT, Data Release 4) counterpart to assess their expected TeV emission. We focused on the objects with a maximum chance of being detected by current or future TeV detectors, based on selections on their X-ray-to-radio flux ratio and their synchrotron peak frequency. In conclusion, we determined if the X-ray emission can be used as an effective proxy to find and characterize candidate TeV-emitting blazars.

Blazars are active galactic nuclei whose ultra-relativistic jets are co-aligned with the observer direction. They emit throughout the whole e.m. spectrum, from radio waves to VHE gamma rays. Not all blazars are discovered. In this work, we propose a catalog of new highly probable candidates based on the association of HE gamma ray emission and radio, X-ray an optical signatures. The relevance of this work is also that it was performed by four high school students from the Liceo Ugo Morin in Venice, Italy using the open-source platform Open Universe in collaboration with the University of Padova. The framework of the activity is the Italian MIUR PCTO programme. The success of this citizen-science experience and results are hereafter reported and discussed.

The Earth atmosphere is constantly reached by cosmic rays, i.e. energetic and subatomic particles coming from all directions from space. A muon telescope is housed at the Legnaro National Laboratories (LNL) of the Italian Istituto Nazionale di Fisica Nucleare (INFN). This instrument is used to introduce students to research activities in the field of particle physics. In particular, during the International Cosmic Day (ICD) and in following Pathways for Transversal Competences and Orientation (PCTO) activities, students can perform measurements and data analysis of the muon flux reaching the Earth’s surface. It is well known that this flux is affected by the atmospheric condition in which the measurement is done. In this contribution, we present the long-term investigation performed with high school and bachelor students in Physics at the University of Padova, of the anticorrelation between muon counts and atmospheric pressure as measured with the muon telescope in LNL using the data collected from 2022 to 2024. The results of our analysis confirm the stability of this anticorrelation during data collection. Further analyses allow us to investigate also the time variations of these correlations in different months, indicating a possible effect due to summer and winter conditions and finally with the recent high solar activity. Currently we are investigating also the impact of other atmospheric-related correlations, such as temperature and humidity.

Nevirapine is widely used to treat HIV-1 infection to prevent mother-to-child transmission; unfortunately adverse drug reactions have been reported. Our aim was to identify genes/variants involved in nevirapine-induced hepatotoxicity. Patients from Mozambique, 78 with nevirapine-induced hepatotoxicity and 78 without adverse events, were genotyped for , , and gene variants. We conducted a case-–control association study and a genotype/phenotype correlation analysis. The c.3435C>T SNP was associated with hepatotoxicity (p = 0.038), with the variant T allele showing a protective effect (odds ratio: 0.42). Moreover, four SNPs in the and genes resulted significantly correlated with transaminase values. In particular, for the c.983T>C SNP, the difference in the alanine aminotransferase mean values were highly significant between TT and TC genotypes (p < 0.001). Our preliminary results confirm the contribution of the c.3435C>T SNP in nevirapine-induced hepatotoxicity risk and, at the same time, suggest the necessity for further studies.

The Cherenkov Telescope Array Observatory (CTAO) is a next-generation facility comprised of ground-based Imaging Atmospheric Cherenkov Telescopes (IACTs). The observatory, currently under construction, will include more than 70 telescopes at two locations: in the northern hemisphere, CTAO-North at the Observatorio del Roque de Los Muchachos (ORM), La Palma, Canary Islands, Spain, and in the southern hemisphere, CTAO-South at a site belonging to the European Southern Observatory (ESO), Cerro Paranal, Chile. IACTs indirectly detect high-energy cosmic photons in an energy range from tens of GeV to several hundreds of TeV by measuring Cherenkov light emitted by atmospheric showers of secondary particles, produced through interactions between incident photons and nuclei of atmospheric gasses in the upper layers. The size of the CTAO will improve the detection sensitivity in the designed energy range by about an order of magnitude with respect to present experiments and aim at improved energy and angular resolution, as well as greatly reduced systematic uncertainties. The key to achieving improvements in accuracy on the absolute energy and flux scales is the precise monitoring of the atmospheric properties for the Cherenkov light, which can be obtained with a specifically designed LIDAR. The Barcelona Raman LIDAR (BRL) prototype is the official CTAO-North Pathfinder and was deployed at ORM for extensive tests between February 2021 and May 2022. We report the BRL’s prospects for the CTAO-North, emphasizing the technical implementation and the preliminary data taken during its deployment period.

The Cherenkov Telescope Array Observatory (CTAO), currently under construction, is the next-generation very-high-energy gamma-ray observatory, providing the coverage for photons in the energy range 20GeV to 300TeV. CTAO will increase detection sensitivity in the 100 GeV to 10TeV range by a factor of 5 — 10 with respect to present experiments. CTAO retrieves the properties of very-high-energy gamma-rays by measuring Cherenkov light emitted by atmospheric showers of secondary particles that incident gamma rays produce in upper layers of the atmosphere. The key for reaching the required energy measurement accuracy is a precise knowledge of the atmospheric transmittance for Cherenkov light, which can be obtained using a dedicated Raman LIDAR. The device should operate at 355nm (near the maximum of Cherenkov light spectrum) and have the capability of taking data at specific azimuth and zenith angles up to distances of 30 km, so that atmospheric transmission along all possible air-shower directions can be determined. The Barcelona Raman LIDAR (BRL) is the official CTAO Pathfinder prototype, developed for atmospheric characterization of the Northern CTAO Site at the Observatorio del Roque de los Muchachos (ORM) on the Canary island of La Palma. BRL was deployed at ORM for extensive on-field tests between February 2021 and May 2022. We report on the commissioning results, including the remote operation capabilities of the system and its contribution to the understanding of atmospheric phenomena during its deployment period. In particular, we report on the properties of the volcanic plume from the eruption of the Cumbre Vieja volcano on 22 September 2021.

Long-duration γ-ray bursts (GRBs) are the most luminous sources of electromagnetic radiation known in the Universe. They arise from outflows of plasma with velocities near the speed of light that are ejected by newly formed neutron stars or black holes (of stellar mass) at cosmological distances 1 , 2 . Prompt flashes of megaelectronvolt-energy γ-rays are followed by a longer-lasting afterglow emission in a wide range of energies (from radio waves to gigaelectronvolt γ-rays), which originates from synchrotron radiation generated by energetic electrons in the accompanying shock waves 3 , 4 . Although emission of γ-rays at even higher (teraelectronvolt) energies by other radiation mechanisms has been theoretically predicted 5 – 8 , it has not been previously detected 7 , 8 . Here we report observations of teraelectronvolt emission from the γ-ray burst GRB 190114C. γ-rays were observed in the energy range 0.2–1 teraelectronvolt from about one minute after the burst (at more than 50 standard deviations in the first 20 minutes), revealing a distinct emission component of the afterglow with power comparable to that of the synchrotron component. The observed similarity in the radiated power and temporal behaviour of the teraelectronvolt and X-ray bands points to processes such as inverse Compton upscattering as the mechanism of the teraelectronvolt emission 9 – 11 . By contrast, processes such as synchrotron emission by ultrahigh-energy protons 10 , 12 , 13 are not favoured because of their low radiative efficiency. These results are anticipated to be a step towards a deeper understanding of the physics of GRBs and relativistic shock waves. Observations of teraelectronvolt-energy γ-rays starting about one minute after the γ-ray burst GRB 190114C reveal a distinct component of the afterglow emission with power comparable to the synchrotron emission.

Currently the detection of Very High Energy gamma-rays for astrophysics rely on the measurement of the Extensive Air Showers (EAS) either using Cherenkov detectors or EAS arrays with larger field of views but also larger energy thresholds. In this talk we present a novel hybrid detector concept for a EAS array with an improved sensitivity in the lower energies (~ 100 GeV). We discuss its main features, capabilities and present preliminary results on its expected perfomances and sensitivities.This wide field of view experiment is planned to be installed at high altitude in South America making it a complementary project to the planned Cherenkov telescope experiments and a powerful tool to trigger further observations of variable sources and to detect transients phenomena.

Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry but still suffer from insufficient angular resolution. An alternative method to resolve small structures is to measure the time variability of their emission. Here we report on gamma-ray observations of the radio galaxy IC 310 obtained with the MAGIC (Major Atmospheric Gamma-ray Imaging Cherenkov) telescopes, revealing variability with doubling time scales faster than 4.8 min. Causality constrains the size of the emission region to be smaller than 20% of the gravitational radius of its central black hole. We suggest that the emission is associated with pulsar-like particle acceleration by the electric field across a magnetospheric gap at the base of the radio jet.