Related papers: Impact of angular differential imaging on circumst…
The angular differential imaging (ADI) is used to improve contrast in high resolution astronomical imaging. An example is the direct imaging of exoplanet in camera fed by Extreme Adaptive Optics. The subtraction of the main dazzling object…
Direct imaging of exoplanets is limited by bright quasi-static speckles in the point spread function (PSF) of the central star. This limitation can be reduced by subtraction of reference PSF images. We have developed an algorithm to…
Reference star differential imaging (RDI) is a powerful strategy for high contrast imaging. Using example observations taken with the vortex coronagraph mode of Keck/NIRC2 in $L^\prime$ band, we demonstrate that RDI provides improved…
Ptychography in a reflection geometry shows great promise for non-destructive imaging of 3-dimensional nanostructures at the surface of a thick substrate. A major challenge to obtain high quality reflection-ptychographic images under…
During the past decade circumbinary disks have been discovered around various young binary stars. Hydrodynamical calculations indicate that the gravitational interaction between the central binary star and the surrounding disk results in…
Context. The analysis of observations of circumstellar disks around young stellar objects is often based on models with a smooth and continuous density distribution. However, spatially resolved observations with increasing angular…
We present a new processing technique aimed at significantly improving the angular differential imaging method (ADI) in the context of high-contrast imaging of faint objects nearby bright stars in observations obtained with extreme adaptive…
Recent developments in astronomical observations enable direct imaging of circumstellar disks. Precise characterization of such extended structure is essential to our understanding of stellar systems. However, the faint intensity of the…
Doppler Imaging (DI) is a well-established technique to map a physical field at a stellar surface from a time series of high-resolution spectra. In this proof-of-concept study, we aim to show that traditional DI algorithms, originally…
Direct imaging of exoplanets is particularly challenging due to the high contrast between the planet and the star luminosities, and their small angular separation. In addition to tailored instrumental facilities implementing adaptive optics…
Circumstellar disks are the cradles of planetary systems and their physical and chemical properties directly influence the planet formation process. As most planets supposedly form in the inner disk regions, i.e., within a few tens of AU,…
We present optical and near-infrared high contrast images of the transitional disk HD 100546 taken with the Magellan Adaptive Optics system (MagAO) and the Gemini Planet Imager (GPI). GPI data include both polarized intensity and total…
Current models of binary systems often depend on simplified approach of the radiation field, which are unlikely to accurately capture the complexities of asymmetric environments. We investigate the dynamical and chemical implications of a…
Abridged: Debris disks are valuable systems to study dust properties. Because they are optically thin at all wavelengths, we have direct access to the properties of dust grains. One very promising technique to study them is to measure their…
Angular differential imaging (ADI) and spectral differential imaging (SDI) are commonly used for direct detection and characterisation of young, Jovian exoplanets in datasets obtained with the SPHERE/IFS instrument. We compare the…
Images from adaptive optics systems are generally affected by significant distortions of the point spread function (PSF) across the field of view, depending on the position of natural and artificial guide stars. Image reduction techniques…
We have discovered an anomalous behavior of CCD readout electronics that affects their use in many astronomical applications. An offset in the digitization of the CCD output voltage that depends on the binary encoding of one pixel is added…
Diffusion MRI is the modality of choice to study alterations of white matter. In past years, various works have used diffusion MRI for automatic classification of AD. However, classification performance obtained with different approaches is…
Resolved observations of debris discs can be used to derive radial profiles of Azimuthally-averaged Surface Density (ASD), which carries important information about the disc structure even in presence of non-axisymmetric features and has…
Many adaptive optics systems operate by measuring the distortion of the wavefront in one wavelength range and performing the scientific observations in a second, different wavelength range. One common technique is to measure wavefront…