752 research outputs found

    EUSO-SPB1 mission and science

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    International audienceThe Extreme Universe Space Observatory on a Super Pressure Balloon 1 (EUSO-SPB1) was launched in 2017 April from Wanaka, New Zealand. The plan of this mission of opportunity on a NASA super pressure balloon test flight was to circle the southern hemisphere. The primary scientific goal was to make the first observations of ultra-high-energy cosmic-ray extensive air showers (EASs) by looking down on the atmosphere with an ultraviolet (UV) fluorescence telescope from suborbital altitude (33 km). After 12 days and 4 h aloft, the flight was terminated prematurely in the Pacific Ocean. Before the flight, the instrument was tested extensively in the West Desert of Utah, USA, with UV point sources and lasers. The test results indicated that the instrument had sensitivity to EASs of ⪆3 EeV. Simulations of the telescope system, telescope on time, and realized flight trajectory predicted an observation of about 1 event assuming clear sky conditions. The effects of high clouds were estimated to reduce this value by approximately a factor of 2. A manual search and a machine-learning-based search did not find any EAS signals in these data. Here we review the EUSO-SPB1 instrument and flight and the EAS search

    EUSO-Offline: A comprehensive simulation and analysis framework

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    International audienceThe complexity of modern cosmic ray observatories and therich data sets they capture often require a sophisticated softwareframework to support the simulation of physical processes, detectorresponse, as well as reconstruction and analysis of real andsimulated data. Here we present the EUSO-Offline framework. Thecode base was originally developed by the Pierre AugerCollaboration, and portions of it have been adopted by othercollaborations to suit their needs. We have extended this softwareto fulfill the requirements of Ultra-High Energy Cosmic Raydetectors and very high energy neutrino detectors developed for theJoint Exploratory Missions for an Extreme Universe Observatory(JEM-EUSO). These path-finder instruments constitute a program tochart the path to a future space-based mission like POEMMA. Forcompleteness, we describe the overall structure of the frameworkdeveloped by the Auger collaboration and continue with a descriptionof the JEM-EUSO simulation and reconstruction capabilities. Theframework is written predominantly in modern C++ (compliled againstC++17) and incorporates third-party libraries chosen based onfunctionality and our best judgment regarding support andlongevity. Modularity is a central notion in the framework design, arequirement for large collaborations in which many individualscontribute to a common code base and often want to compare differentapproaches to a given problem. For the same reason, the framework isdesigned to be highly configurable, which allows us to contend witha variety of JEM-EUSO missions and observation scenarios. We alsodiscuss how we incorporate broad, industry-standard testing coveragewhich is necessary to ensure quality and maintainability of arelatively large code base, and the tools we employ to support amultitude of computing platforms and enable fast, reliableinstallation of external packages. Finally, we provide a fewexamples of simulation and reconstruction applications usingEUSO-Offline

    EUSO-Offline: A comprehensive simulation and analysis framework

    No full text
    International audienceThe complexity of modern cosmic ray observatories and therich data sets they capture often require a sophisticated softwareframework to support the simulation of physical processes, detectorresponse, as well as reconstruction and analysis of real andsimulated data. Here we present the EUSO-Offline framework. Thecode base was originally developed by the Pierre AugerCollaboration, and portions of it have been adopted by othercollaborations to suit their needs. We have extended this softwareto fulfill the requirements of Ultra-High Energy Cosmic Raydetectors and very high energy neutrino detectors developed for theJoint Exploratory Missions for an Extreme Universe Observatory(JEM-EUSO). These path-finder instruments constitute a program tochart the path to a future space-based mission like POEMMA. Forcompleteness, we describe the overall structure of the frameworkdeveloped by the Auger collaboration and continue with a descriptionof the JEM-EUSO simulation and reconstruction capabilities. Theframework is written predominantly in modern C++ (compliled againstC++17) and incorporates third-party libraries chosen based onfunctionality and our best judgment regarding support andlongevity. Modularity is a central notion in the framework design, arequirement for large collaborations in which many individualscontribute to a common code base and often want to compare differentapproaches to a given problem. For the same reason, the framework isdesigned to be highly configurable, which allows us to contend witha variety of JEM-EUSO missions and observation scenarios. We alsodiscuss how we incorporate broad, industry-standard testing coveragewhich is necessary to ensure quality and maintainability of arelatively large code base, and the tools we employ to support amultitude of computing platforms and enable fast, reliableinstallation of external packages. Finally, we provide a fewexamples of simulation and reconstruction applications usingEUSO-Offline

    Simulation studies for the Mini-EUSO detector

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    Mini-EUSO is a mission of the JEM-EUSO program flying onboard the International Space Station since August 2019. Since the first data acquisition in October 2019, more than 35 sessions have been performed for a total of 52 hours of observations. The detector has been observing Earth at night-time in the UV range and detected a wide variety of transient sources all of which have been modelled through Monte Carlo simulations. Mini-EUSO is also capable of detecting meteors and potentially space debris and we performed simulations for such events to estimate their impact on future missions for cosmic ray science from space. We show here examples of the simulation work done in this framework to analyse the Mini-EUSO data. The expected response of Mini-EUSO with respect to ultra high energy cosmic ray showers has been studied. The efficiency curve of Mini-EUSO as a function of primary energy has been estimated and the energy threshold for Cosmic Rays has been placed to be above 1021^{21} eV. We compared the morphology of several transient events detected during the mission with cosmic ray simulations and excluded that they can be due to cosmic ray showers. To validate the energy threshold of the detector, a system of ground based flashers is being used for end-to-end calibration purposes. We therefore implemented a parameterisation of such flashers into the JEM-EUSO simulation framework and studied the response of the detector with respect to such sources

    Time Dependence of 50-250 MeV Galactic Cosmic-Ray Protons between Solar Cycles 24 and 25, Measured by the High-energy Particle Detector on board the CSES-01 Satellite

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    Time-dependent energy spectra of galactic cosmic rays (GCRs) carry crucial information regarding their origin and propagation throughout the interstellar environment. When observed at the Earth, after traversing the interplanetary medium, such spectra are heavily affected by the solar wind and the embedded solar magnetic field permeating the inner sectors of the heliosphere. The activity of the Sun changes significantly over an 11 yr solar cycle‚ÄĒand so does the effect on cosmic particles; this translates into a phenomenon called solar modulation. Moreover, GCR spectra during different epochs of solar activity provide invaluable information for a complete understanding of the plethora of mechanisms taking place in various layers of the Sun‚Äôs atmosphere and how they evolve over time. The High-Energy Particle Detector (HEPD-01) has been continuously collecting data since 2018 August, during the quiet phase between solar cycles 24 and 25; the activity of the Sun is slowly but steadily rising and is expected to peak around 2025/2026. In this paper, we present the first spectra for ‚ąľ50-250 MeV galactic protons measured by the HEPD-01 instrument‚ÄĒplaced on board the CSES-01 satellite‚ÄĒfrom 2018 August to 2022 March over a one-Carrington-rotation time basis. Such data are compared to the ones from other spaceborne experiments, present (e.g., EPHIN, Parker Solar Probe) and past (PAMELA), and to a state-of-the-art three-dimensional model describing the GCRs propagation through the heliosphere

    An overview of the JEM-EUSO program and results

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    The field of UHECRs (Ultra-High energy cosmic Rays) and the understanding of particle acceleration in the cosmos, as a key ingredient to the behaviour of the most powerful sources in the universe, is of outmost importance for astroparticle physics as well as for fundamental physics and will improve our general understanding of the universe. The current main goals are to identify sources of UHECRs and their composition. For this, increased statistics is required. A space-based detector for UHECR research has the advantage of a very large exposure and a uniform coverage of the celestial sphere. The aim of the JEM-EUSO program is to bring the study of UHECRs to space. The principle of observation is based on the detection of UV light emitted by isotropic Ô¨āuorescence of atmospheric nitrogen excited by the Extensive Air Showers (EAS) in the Earth‚Äôs atmosphere and forward-beamed Cherenkov radiation reÔ¨āected from the Earth‚Äôs surface or dense cloud tops. In addition to the prime objective of UHECR studies, JEM-EUSO will do several secondary studies due to the instruments\u27 unique capacity of detecting very weak UV-signals with extreme time-resolution around 1 microsecond: meteors, Transient Luminous Events (TLE), bioluminescence, maps of human generated UV-light, searches for Strange Quark Matter (SQM) and high-energy neutrinos, and more. The JEM-EUSO program includes several missions from ground (EUSO-TA), from stratospheric balloons (EUSO-Balloon, EUSO-SPB1, EUSO-SPB2), and from space (TUS, Mini-EUSO) employing fluorescence detectors to demonstrate the UHECR observation from space and prepare the large size missions K-EUSO and POEMMA. A review of the current status of the program, the key results obtained so far by the different projects, and the perspectives for the near future are presented

    Science and mission status of EUSO-SPB2

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    The Extreme Universe Space Observatory on a Super Pressure Balloon II (EUSO-SPB2) is a second generation stratospheric balloon instrument for the detection of Ultra High Energy Cosmic Rays (UHECRs, E > 1 EeV) via the fluorescence technique and of Very High Energy (VHE, E > 10 PeV) neutrinos via Cherenkov emission. EUSO-SPB2 is a pathfinder mission for instruments like the proposed Probe Of Extreme Multi-Messenger Astrophysics (POEMMA). The purpose of such a space-based observatory is to measure UHECRs and UHE neutrinos with high statistics and uniform exposure. EUSO-SPB2 is designed with two Schmidt telescopes, each optimized for their respective observa- tional goals. The Fluorescence Telescope looks at the nadir to measure the fluorescence emission from UHECR-induced extensive air shower (EAS), while the Cherenkov Telescope is optimized for fast signals (‚ąľ10 ns) and points near the Earth‚Äôs limb. This allows for the measurement of Cherenkov light from EAS caused by Earth skimming VHE neutrinos if pointed slightly below the limb or from UHECRs if observing slightly above. The expected launch date of EUSO-SPB2 is Spring 2023 from Wanaka, NZ with target duration of up to 100 days. Such a flight would provide thousands of VHECR Cherenkov signals in addition to tens of UHECR fluorescence tracks. Neither of these kinds of events have been observed from either orbital or suborbital altitudes before, making EUSO-SPB2 crucial to move forward towards a space-based instrument. It will also enhance the understanding of potential background signals for both detection techniques. This contribution will provide a short overview of the detector and the current status of the mission as well as its scientific goals

    Measurement of UV light emission of the nighttime Earth by Mini-EUSO for space-based UHECR observations

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    The JEM-EUSO (Joint Experiment Missions for Extreme Universe Space Observatory) program aims at the realization of the ultra-high energy cosmic ray (UHECR) observation using wide field of view fluorescence detectors in orbit. Ultra-violet (UV) light emission from the atmosphere such as airglow and anthropogenic light on the Earth\u27s surface are the main background for the space-based UHECR observations. The Mini-EUSO mission has been operated on the International Space Station (ISS) since 2019 which is the first space-based experiment for the program. The Mini-EUSO instrument consists of a 25 cm refractive optics and the photo-detector module with the 2304-pixel array of the multi-anode photomultiplier tubes. On the nadir-looking window of the ISS, the instrument is capable of continuously monitoring a ~300 km x 300 km area. In the present work, we report the preliminary result of the measurement of the UV light in the nighttime Earth using the Mini-EUSO data downlinked to the ground. We mapped UV light distribution both locally and globally below the ISS obit. Simulations were also made to characterize the instrument response to diffuse background light. We discuss the impact of such light on space-based UHECR observations and the Mini-EUSO science objectives

    Towards observations of nuclearites in Mini-EUSO

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    Mini-EUSO is a small orbital telescope with a field of view of 44¬į x 44¬į,observing the night-time Earth mostly in 320-420 nm band. Its time resolution spanning from microseconds (triggered) to milliseconds (untriggered) and more than 300√ó300 km of the ground covered, already allowed it to register thousands of meteors. Such detections make the telescope a suitable tool in the search for hypothetical heavy compact objects, which would leave trails of light in the atmosphere due to their high density and speed. The most prominent example are the nuclearites -- hypothetical lumps of strange quark matter that could be stabler and denser than the nuclear matter. In this paper, we show potential limits on the flux of nuclearites after collecting 42 hours of observations data
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