122,223 research outputs found
Science with the ASTRI mini-array for the Cherenkov Telescope Array: Blazars and fundamental physics
Get PDFASTRI ("Astronomia a Specchi con Tecnologia Replicante Italiana") is a flagship project of the Italian Ministry of Research (MIUR), devoted to the realization, operation and scientific validation of an end-to-end prototype for the Small Size Telescope (SST) envisaged to become part of the Cherenkov Telescope Array (CTA). The ASTRI SST-2M telescope prototype is characterized by a dual mirror, Schwarzschild-Couder optical design and a compact camera based on silicon photo-multipliers. It will be sensitive to multi-TeV very high energy (VHE) gamma rays up to 100 TeV, with a PSF ∼ 6′ and a wide (9.6°) unaberrated optical field of view. Right after validation of the design in single-dish observations at the Serra La Nave site (Sicily, Italy) during 2015, the ASTRI collaboration will be able to start deployment, at the final CTA southern site, of the ASTRI mini-array, proposed to constitute the very first CTA precursor. Counting 9 ASTRI SST-2M telescopes, the ASTRI mini-array will overtake current IACT systems in differential sensitivity above 5 TeV, thus allowing unprecedented observations of known and predicted bright TeV emitters in this band, including some extragalactic sources such as extreme high-peaked BL Lacs with hard spectra. We exploited the ASTRI scientific simulator ASTRIsim in order to understand the feasibility of observations tackling blazar and cosmic ray physics, including discrimination of hadronic and leptonic scenarios for the VHE emission from BL Lac relativistic jets and indirect measurements of the intergalactic magnetic field and of the extragalactic background light. We selected favorable targets, outlining observation modes, exposure times, multi-wavelength coverage needed and the results expected. Moreover, the perspectives for observation of effects due to the existence of axion-like particles or to Lorentz invariance violations have been investigated
Development of ASTRI high-temperature solar receivers
Get PDFThree high-temperature solar receiver design concepts are being evaluated as part of the Australian Solar Thermal Research Initiative (ASTRI): a flux-optimised sodium receiver, a falling particle receiver, and an expanding-vortex particle receiver. Preliminary results from performance modelling of each concept are presented. For the falling particle receiver, it is shown how particle size and flow rate have a significant influence on absorptance. For the vortex receiver, methods to reduce particle deposition on the window and increase particle residence time are discussed. For the sodium receiver, the methodology for geometry optimisation is discussed, as well as practical constraints relating to containment materialsThis research was performed as part of the Australian Solar Thermal Research Initiative (ASTRI), a project
supported by the Australian Government, through the Australian Renewable Energy Agency (ARENA)
Scientific prospects for a mini-array of ASTRI telescopes: A -ray TeV data challenge
Get PDFInternational audienceASTRI is a project aiming at the realization of a γ -ray imaging Cherenkov telescope that observes the sky in the TeV band. Recently, the development of a mini-array (MA) of ASTRI telescopes has been funded by the Istituto Nazionale di Astrofisica. The ASTRI Comprehensive Data Challenge (ACDC) project aims at optimizing the scientific exploitation and analysis techniques of the ASTRI MA, by performing a complete end-to-end simulation of a tentative scientific program, from the generation of suitable instrument response functions to the proposal, selection, analysis, and interpretation of the simulated data. We assumed that the MA will comprise nine ASTRI telescopes arranged in a (almost) square geometry (mean distance between telescopes of ∼250m). We simulated three years of observations, adopting a realistic pointing plan that takes into account, for each field, visibility constraints for an assumed site in Paranal (Chile) and observational time slots in dark sky conditions. We simulated the observations of nineteen Galactic and extragalactic fields selected for their scientific interest, including several classes of objects (such as pulsar wind nebulae, supernova remnants, γ -ray binaries etc), for a total of 81 point-like and extended sources. Here we present an overview of the ACDC project, providing details on the different software packages needed to carry out the simulated three-years operation of the ASTRI MA. We discuss the results of a systematic analysis applied on the whole simulated data, by making use of prototype science tools widely adopted by the TeV astronomical community. Furthermore, particular emphasis is also given to some targets used as benchmarks
The ASTRI Mini-Array Software System
No full textASTRI ("Astrofisica con Specchi a Tecnologia Replicante Italiana") is a
Flagship Project financed by the Italian Ministry of Education,
University and Research, and led by INAF, the Italian National Institute
of Astrophysics. Main goals of the ASTRI project are the realization of
an end-to-end prototype of a Small Size Telescope (SST) for the
Cherenkov Telescope Array (CTA) in a dual-mirror configuration (SST-2M)
and, subsequently, of a mini-array composed of a few SST-2M telescopes
to be placed at the final CTA Southern Site. Here we present the main
features of the Mini-Array Software System (MASS) that has a central
role in the success of the ASTRI Project and will also serve as a
prototype for the CTA software system. The MASS will provide a set of
tools to prepare an observing proposal, to perform the observations
specified therein (monitoring and controlling all the hardware
components of each telescope), to analyze the acquired data online and
to store/retrieve all the data products to/from the archive
ASTRI Mini-Array core science at the Observatorio del Teide
Get PDFThe ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) Project led by the Italian National Institute for Astrophysics (INAF) is developing and will deploy at the Observatorio del Teide a mini-array (ASTRI Mini-Array) composed of nine telescopes similar to the small-size dual-mirror Schwarzschild-Couder telescope (ASTRI-Horn) currently operating on the slopes of Mt. Etna in Sicily. The ASTRI Mini-Array will surpass the current Cherenkov telescope array differential sensitivity above a few teraelectronvolt (TeV), extending the energy band well above hundreds of TeV. This will allow us to explore a new window of the electromagnetic spectrum, by convolving the sensitivity performance with excellent angular and energy resolution figures. In this paper we describe the Core Science that we will address during the first four years of operation, providing examples of the breakthrough results that we will obtain when dealing with current open questions, such as the acceleration of cosmic rays, cosmology and fundamental physics and the new window, for the TeV energy band, of the time-domain astrophysics. (c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
The mini-array of ASTRI SST-2M telescopes, precursors for the Cherenkov Telescope Array
Get PDFIn the framework of the Cherenkov Telescope Array (CTA) Observatory, the Italian National Institute of Astrophysics (INAF) has recently inaugurated in Sicily (Italy), at the Serra La Nave astronomical site on the slopes of Mount Etna, a large field of view (FoV, ∼ 9.6°) dual-mirror prototype (ASTRI SST-2M) of the CTA small size class of telescopes (SST). The CTA plans to install about 70 SST in the southern site to allow the study of the gamma rays from a few TeV up to hundreds of TeV. The ASTRI SST-2M telescope prototype has been developed following an end-to-end approach, since it includes the entire system of structure, mirrors optics (primary and secondary mirrors), camera, and control/acquisition software. A remarkable performance improvement could come from the operation of the ASTRI mini-array, led by INAF in synergy with the Universidade de Sao Paulo (Brazil) and the North-West University (South Africa). The ASTRI mini-array will be composed of nine ASTRI SST-2M units and it is proposed as a precursor and initial seed of the CTA to be installed at the final CTA southern site. Apart from the assessment of a number of technological aspects related to the CTA, the ASTRI mini-array will, if compared for instance to H.E.S.S., extend the point source sensitivity up to ∼ 100 TeV, also improving it above 5-10 TeV. Moreover, the unprecedented width of the FoV, with its homogeneous acceptance and angular resolution, will significantly contribute to the achievement of original results during the early CTA science phase
ASTRI Mini-Array core science at the Observatorio del Teide
No full textThe ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) Project led by the Italian National Institute for Astrophysics (INAF) is developing and will deploy at the Observatorio del Teide a mini-array (ASTRI Mini-Array) composed of nine telescopes similar to the small-size dual-mirror Schwarzschild-Couder telescope (ASTRI-Horn) currently operating on the slopes of Mt. Etna in Sicily. The ASTRI Mini-Array will surpass the current Cherenkov telescope array differential sensitivity above a few tera-electronvolt (TeV), extending the energy band well above hundreds of TeV. This will allow us to explore a new window of the electromagnetic spectrum, by convolving the sensitivity performance with excellent angular and energy resolution figures. In this paper we describe the Core Science that we will address during the first four years of operation, providing examples of the breakthrough results that we will obtain when dealing with current open questions, such as the acceleration of cosmic rays, cosmology and fundamental physics and the new window, for the TeV energy band, of the time-domain astrophysics
Space Career & Educational Opportunities through the ASTRI Programme
No full textThe following paper describes the purpose and benefits of the Advanced Student Team Research in space Industry (ASTRI) programme, as well as an example and programmatic outcome of a pilot project under the programme implemented by OHB SE. The ASTRI programme is a collaboration between European universities and private aerospace companies, and seeks to provide a structured transition between students’ academic curriculum and their entry into the industry. There are three main ASTRI stakeholders, and their positive outcomes of participating in the programme are identified and listed. One of the main benefits is the establishment of a young and well-prepared talent pool of engineers. OHB System, an established industry actor based in Germany, and the OHB SE subsidiary Blue Horizon, based in Luxembourg, participated in the first round of the ASTRI programme by proposing a project to develop a viable commercial micro moon lander concept. For their ASTRI project, OHB implemented new approaches such as Concept Maturity Levels (CMLs) as a way to structure an 18-month long phase 0/A/B1 feasibility study. Each team member was given a role in the project. The roles typically included a technical aspect, where each member was responsible for designing a particular subsystem of the spacecraft, and a non-technical aspect, which could include topics such as business development, cost analysis, and project control.The technical output of OHB’s project include a developed lander concept seeking to accommodate a wide variety of customers and payload types by providing not only transportation to the lunar surface, but also necessary infrastructure needed by the payloads to successfully complete their missions. These infrastructure service concepts are geared towards eventually providing support for permanent human lunar settlement, a vision that will hopefully bring space exploration closer to the public and inspire the next generations
A Stellar Intensity Interferometry Instrument for the ASTRI Mini-Array telescopes
No full textThe ASTRI Mini-Array is an International collaboration, led by the Italian National Institute for Astrophysics, that is constructing and operating an array of nine Imaging Atmospheric Cherenkov Telescopes to study gamma-ray sources at very high energy and perform optical stellar intensity interferometry (SII) observations. Angular resolutions below 100 microarcsec are achievable with stellar intensity interferometry, using telescopes separated by hundreds to thousands of meters baselines. At this level of resolution it turns out to be possible to reveal details on the surface and of the environment surrounding bright stars on the sky. The ASTRI Mini-Array will provide a suitable infrastructure for performing these measurements thanks to the capabilities offered by its 9 telescopes, which provide 36 simultaneous baselines over distances between 100 m and 700 m. After providing an overview of the scientific context and motivations for performing SII science with the ASTRI Mini-Array telescopes, we present the baseline design for the ASTRI Stellar Intensity Interferometry Instrument, a fast single photon counting instrument that will be mounted on the ASTRI telescopes and dedicated to performing SII observations of bright stars
A new version of the Stellar Intensity Interferometry Instrument for the ASTRI Mini-Array telescopes
No full textThe ASTRI Stellar Intensity Interferometry Instrument (SI3) is a fast single photon counting instrument for performing intensity interferometry observations of bright stars with the ASTRI Mini-Array∗. SI3 is designed to perform accurate measurements of single photon arrival times (1 ns) in a narrow optical bandwidth (1-8 nm) centered at a wavelength in the range 420-500 nm. The instrument will exploit the 36 simultaneous baselines over distances between 100 m and 700 m of the ASTRI Mini-Array to achieve angular resolutions below 100 microarcsec. At this level of resolution it turns out to be possible to reveal details on the surface and of the environment surrounding bright stars on the sky. During 2023 SI3 underwent a significant redesign, with an optical fiber positioned on the focal plane to feed the detectors and electronics. Here we present this new baseline design of SI3, and the motivations behind this choice, including the possibility of future upgrades of the instrument with dedicated front-end electronics and channel multiplexing. We will also show the first results of the target selection procedure based on simulations. Stars with angular diameters of less than 500-600 microarcseconds up to about magnitude 4.5 will be observable. Thanks to the 36 simultaneous baselines, accurate (up to ∼1%) angular measurements can be obtained with 10-30 hours of observations. This accuracy can rival with that obtained with other arrays of Cherenkov telescopes, despite the smaller collecting area of a single ASTRI telescope
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