Related papers: Fresnel Zone Plate Telescopes as high resolution i…
In the recent years, interferometric arrays of optical telescopes have reached sizes of the order of 100m, but they have yet to produce high-resolution images. The analysis of image formation now shows that such images are obtainable…
Future Extremely Large Telescopes will adopt segmented primary mirrors with several hundreds of segments. Cophasing of the segments together is essential to reach high wavefront quality. The phasing sensor must be able to maintain very high…
A laboratory prototype spectral/spatial interferometer has been constructed to demonstrate the feasibility of the double Fourier technique at Far Infrared (FIR) wavelengths (0.15 - 1 THz). It is planned to use this demonstrator to…
The Virtual Telescope for X-Ray Observations (VTXO) is a conceptual mission under development to demonstrate a new instrument for astronomical observations in the X-ray band using a set of 6U CubeSats. VTXO will use a Phase Fresnel Lens,…
Optical interferometers may not require a phase-stable optical link between the stations if instead sources of quantum-mechanically entangled pairs could be provided to them, enabling long baselines. We developed a new variation of this…
We study image formation with the solar gravitational lens (SGL). We consider a point source that is positioned at a large but finite distance from the Sun. We assume that an optical telescope is positioned in the image plane, in the focal…
A large fraction of the present-day stellar mass was formed between z=0.5 and z~3 and our understanding of the formation mechanisms at work at these epochs requires both high spatial and high spectral resolution: one shall simultaneously}…
Multi-wavelength study of extended astronomical objects requires combining images from instruments with differing point spread functions (PSFs). We describe the construction of convolution kernels that allow one to generate…
Remote-sensing observations of Solar System objects with a space telescope offer a key method of understanding celestial bodies and contributing to planetary formation and evolution theories. The capabilities of Twinkle, a space telescope…
The performance of the three X-ray telescopes on-board of XMM-Newton is evaluated addressing imaging characteristics and effective collecting area. The agreement with ground calibration data is excellent. The analysis of images and spectra…
Strong gravitational lensing acts as a cosmic telescope, enabling the study of the high-redshift universe. Astronomical interferometers, such as the Atacama Large Millimeter/submillimeter Array (ALMA), have provided high-resolution images…
We present a multi-frequency far-field beam map for the 5m dish telescope at the Bleien Observatory measured using a commercially available drone. We describe the hexacopter drone used in this experiment, the design of the flight pattern,…
Achromatic combinations of a diffractive Phase Fresnel Lens and a refractive correcting element have been proposed for X-ray and gamma-ray astronomy and for microlithography, but considerations of absorption often dictate that the…
Recent adaptive optics systems in astronomy achieve high-angular resolution. With the extreme stability of the images, detection at very low fluxes can be reached using a coronograph at the diffraction limit of the telescopes. This paper is…
We describe a new software package for simulating channelised, high-time resolution data streams from radio telescopes. The software simulates data from the telescope and observing system taking into account the observation strategy,…
This paper presents the design, fabrication and preliminary experimental results of a flexure plate wave (FPW) resonator using sol-gel derived lead zirconate titanates (PZT) thin films. The resonator adopts a two-port structure with…
With its excellent sensitivity, large field of view, broad energy coverage, and good per-photon angular resolution, the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope satellite provides us with an unprecedented view of the…
This paper describes the development of X-ray diffractive optics for imaging solar flares with better than 0.1 arcsec angular resolution. X-ray images with this resolution of the \geq10 MK plasma in solar active regions and solar flares…
We have built and tested a compact, low-cost, but very-high-performance astronomical polarimeter based on a continuously rotating half-wave plate and a high-speed imaging detector. The polarimeter is suitable for small telescopes up to ~1 m…
The exact mechanism for the production of fast $\gamma$-ray variability in blazars remains debated. Magnetic reconnection, in which plasmoids filled with relativistic particles and magnetic fields are formed, is a viable candidate to…