相关论文: Wide band, tunable gamma-ray lenses
Detecting cosmic gamma rays at high rates is the key to time-resolve the acceleration of particles within some of the most powerful events in the universe. Time-resolving the emission of gamma rays from merging celestial bodies, apparently…
The imaging problem of a specular reflector is revisited. Retaining terms through second order in the reflector surface expansion, we derive the form of the aberration-limiting aperture for arbitrary magnification assuming no bandwidth…
The double humped SED (Spectral Energy Distribution) of blazars, and their flaring phenomena can be explained by various leptonic and hadronic models. However, accurate modeling of the high frequency component and clear identification of…
e-ASTROGAM (`enhanced ASTROGAM') is a breakthrough Observatory mission dedicated to the study of the non-thermal Universe in the photon energy range from 0.3 MeV to 3 GeV. The mission is based on an advanced space-proven detector…
The polarimetry of gamma rays converting to an $e^+e^-$ pair would open a new window on the high-energy gamma-ray sky by, among other things, providing insight into the radiation mechanism in pulsars (curvature or synchrotron) or…
Imaging of the Bragg reflected x-ray beam is proposed and validated as an in-situ method for characterization of performance of double-crystal monochromators under the heat load of intense synchrotron radiation. A sequence of images is…
The 10-100 keV region of the electromagnetic spectrum contains the potential for a dramatic improvement in our understanding of a number of key problems in high energy astrophysics. A deep inspection of the universe in this band is on the…
High-energy gamma rays are a valuable tool for studying particle acceleration and radiation in the magnetospheres of energetic pulsars. The seven or more pulsars seen by instruments on the Compton Gamma Ray Observatory (CGRO) show that: the…
The optimal performance of adaptive optics systems can only be maintained if the wavefront reference is bright and compact. Experience has shown that both of these important criteria are remarkably difficult to achieve with laser guide…
Adaptive Optics is a prime example of how progress in observational astronomy can be driven by technological developments. At many observatories it is now considered to be part of a standard instrumentation suite, enabling ground-based…
The Crab Nebula has been observed by the HEGRA (High-Energy Gamma-Ray Astronomy) stereoscopic system of imaging air Cherenkov telescopes (IACTs) for a total of about 200 hrs during two observational campaigns: from September 1997 to March…
Gaia mission will offer an exceptional opportunity to perform variability studies. The data homogeneity, its optimised photometric systems, composed of 11 medium and 4-5 broad bands, the high photometric precision in G band of one milli-mag…
Tunable optical devices, in particular, varifocal lenses, have important applications in various fields, including imaging and adaptive vision. Recent advances in metasurfaces, which control the wavefront of light using subwavelength-spaced…
GAW (Gamma Air Watch) is a new imaging Cherenkov telescope designed for observation of very high-energy gamma-ray sources. GAW will be equipped with a 3 meter diameter Fresnel lens as light collector and with an array of 300 multi-anode…
A new generation of sub-orbital platforms will be operational in the next few years. These new telescopes will operate from airborne and balloon-borne platforms where the atmosphere is transparent enough to allow sensitive measurements to…
In this paper we present a novel telescope composed exclusively of thin, flat optical elements, each being a hot-pressed multi-layered structure combining the properties of a lens, its anti-reflection coating and frequency selection or…
White beam x-ray Laue microdiffraction allows fast mapping of crystal orientation and strain fields in polycrystals, with a submicron spatial resolution in two dimensions. In the well crystallized parts of the grains, the analysis of Laue…
Following the discovery of high-energy (HE; $E>10\,{\rm MeV}$) and very-high-energy (VHE; $E>100\,{\rm GeV}$) $\gamma$-ray emission from the low-frequency-peaked BL~Lac (LBL) object AP Librae, its electromagnetic spectrum is studied over 60…
Hexagonal optical lattices offer a tunable platform to study exotic orbital physics in solid state materials. Here, we present a versatile high-precision scheme to implement a hexagonal optical lattice potential, which is engineered by…
Very high energy (VHE, E >100 GeV) gamma-rays are absorbed via interaction with low-energy photons from the extragalactic background light (EBL) if the involved photon energies are above the threshold for electron-positron pair creation.…