Science with the Cherenkov Telescope Array The Cta Consortium, The Cta Consortium
The Astrophysical journal. Supplement series,
01/2019, Letnik:
240, Številka:
2
eBook, Journal Article, Book
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This book summarizes the science to be carried out by the upcoming Cherenkov Telescope Array, a major ground-based gamma-ray observatory that will be constructed over the next six to eight years. The ...major scientific themes, as well as core program of key science projects, have been developed by the CTA Consortium, a collaboration of scientists from many institutions worldwide. CTA will be the major facility in high-energy and very high-energy photon astronomy over the next decade and beyond. CTA will have capabilities well beyond past and present observatories. Thus, CTA's science program is expected to be rich and broad and will complement other major multiwavelength and multimessenger facilities. This book is intended to be the primary resource for the science case for CTA and it thus will be of great interest to the broader physics and astronomy communities. The electronic version (e-book) is available in open access.
The surface detector array of the Telescope Array experiment Abu-Zayyad, T.; Aida, R.; Anderson, R. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2012, Letnik:
689
Journal Article
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The Telescope Array (TA) experiment, located in the western desert of Utah, USA, is designed for the observation of extensive air showers from extremely high energy cosmic rays. The experiment has a ...surface detector array surrounded by three fluorescence detectors to enable simultaneous detection of shower particles at ground level and fluorescence photons along the shower track. The TA surface detectors and fluorescence detectors started full hybrid observation in March, 2008. In this article we describe the design and technical features of the TA surface detector.
A 600 m2 array of 6.5 m telescopes at the lunar pole Angel, Roger
Philosophical transactions of the Royal Society of London. Series A: Mathematical, physical, and engineering sciences,
05/2024, Letnik:
382, Številka:
2271
Journal Article
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The proposed lunar telescope for optical and infrared astronomy aims at very large aperture, 600 m2, at a fundable cost. It comprises an array of 18 separate telescopes, each of 6.5 m aperture. The ...200 m diameter array will be located within 1/2° (15 km) of a lunar pole on approximately level ground, with a perimeter screen deployed to provide shade and cooling to cryogenic temperature. The 500 m diameter screen will allow unobscured access down to 8° elevation. All 18 telescopes will reflect light into a central beam combiner to form a single image covering wavelengths from 0.4 µm to 10 µm. The initial instrument complement will include high-resolution and multi-object spectrographs to exploit the single combined field of view of two arcminute diameter, with the diffraction limited resolution of 6.5 m aperture. Scientific applications include the search for molecular biosignatures in transiting exoplanets, and the study of galaxy evolution using red-shifted spectra to beyond z = 10. The array cost, including delivery to the Moon by SpaceX Starship for installation using lunar base infrastructure, is around $10 billion, similar to that of the 25 m2 JWST. To test the concept, first a single prototype 6.5 m unit would be operated at the lunar south pole. This article is part of a discussion meeting issue 'Astronomy from the Moon: the next decades (part 2)'.
Previous measurements of the composition of Ultra-High Energy Cosmic Rays (UHECRs) made by the High Resolution Fly’s Eye (HiRes) and Pierre Auger Observatory (PAO) are seemingly contradictory, but ...utilize different detection methods, as HiRes was a stereo detector and PAO is a hybrid detector. The five year Telescope Array (TA) Middle Drum hybrid composition measurement is similar in some, but not all, respects in methodology to PAO, and good agreement is evident between data and a light, largely protonic, composition when comparing the measurements to predictions obtained with the QGSJetII-03 and QGSJet-01c models. These models are also in agreement with previous HiRes stereo measurements, confirming the equivalence of the stereo and hybrid methods. The data is incompatible with a pure iron composition, for all models examined, over the available range of energies. The elongation rate and mean values of Xmax are in good agreement with Pierre Auger Observatory data. This analysis is presented using two methods: data cuts using simple geometrical variables and a new pattern recognition technique.
We present the results of the search for ultra-high-energy photons with nine years of data from the Telescope Array surface detector. A multivariate classifier is built upon 16 reconstructed ...parameters of the extensive air shower. These parameters are related to the curvature and the width of the shower front, the steepness of the lateral distribution function, and the timing parameters of the waveforms sensitive to the shower muon content. A total number of two photon candidates found in the search is fully compatible with the expected background. The 95% CL limits on the diffuse flux of the photons with energies greater than 1018.0, 1018.5, 1019.0, 1019.5 and 1020.0 eV are set at the level of 0.067, 0.012, 0.0036, 0.0013, 0.0013km−2yr−1sr−1 correspondingly.
In this paper the technological aspects of the FAZIA array will be explored. After a productive commissioning phase, FAZIA blocks started to measure and give very useful data to explore the physics ...of Fermi energy heavy-ion reactions. This was possible thanks to many technical measures and innovations developed in the commissioning phase and tuned during the first experimental campaigns. This paper gives a detailed description of the present status of the FAZIA setup from the electronic and mechanical point of view, trying also to trace a path for new improvements and refinements of the apparatus.
The Cherenkov Telescope Array (CTA) is the next generation ground-based gamma-ray astronomy observatory, planned to comprise two arrays of imaging air Cherenkov telescopes (IACTs) located in the ...northern and southern hemispheres. Three telescope sizes are required to cover the CTA gamma-ray energy range from 20 GeV to 300 TeV. An array of several tens of Small-Sized Telescopes (SSTs) at the southern site situated in the Andes at Paranal in Chile, will provide unprecedented sensitivity above 1 TeV and up to 300 TeV, and offer the highest angular resolution of any instrument at these energies. Following a down selection from three prototype telescopes, the design finally selected for SST comprises a dual mirror Schwarzschild–Couder optic with a 4.3 m diameter primary mirror and a 1.8 m secondary mirror imaged by a silicon photomultiplier (SiPM)-based camera with a ∼9°field of view (FoV). The dual mirror optics produce a smaller plate-scale aplanatic focal plane allowing a small, low-cost camera to be employed, compared to that required for the conventional single mirror Davies-Cotton IACT design. The camera comprises an array of 2048 SiPM pixels, configured as 32 sensor and electronics modules each with an 8 × 8 pixel2 tile populated with 6 × 6 mm2 SiPM pixels. Full waveform capture on every channel is provided by the TARGET ASIC which performs the dual function of event triggering and waveform digitization of the full camera at 1 GSample/s. We describe the finalized SST camera design including its optimization for the production phase of the project anticipated to begin in 2023.
The Telescope Array (TA) Cosmic Ray Observatory is the largest cosmic ray detector in the northern hemisphere. TA was built to study ultra-high-energy cosmic rays (UHECRs), cosmic rays with energies ...above 1018eV. TA is a hybrid detector, employing two distinct detection methods: a surface detector array and a set of fluorescence telescopes. We will present a measurement of the cosmic ray energy spectrum for energies above 1017.5eV using only the fluorescence telescopes. A novel weather classification scheme using machine learning was used to select data parts with good weather to ensure the quality of the fluorescence data. The data from the Black Rock Mesa (BRM) and Long Ridge (LR) fluorescence telescope sites were analyzed separately in monocular mode, with the calculated fluxes combined into a single spectrum. The 10-year monocular combined cosmic ray energy spectrum is observed to be in excellent agreement with previous measurements from the northern hemisphere. We present fits of the combined spectrum to a series of broken power law models. The thrice-broken power law was observed to be the best fit considering the Poisson deviance per degrees of freedom. The three breaks suggest an additional feature of the spectrum between the previously observed Ankle feature at 1018.7eV and the GZK suppression at 1019.8eV.