Related papers: Multi-scale and Multi-directional VLBI Imaging wit…
Context. The current algorithms used for the calibration and analysis of very long baseline interferometry (VLBI) networks that only use linear polarizers (as is the case of the VLBI Global Observing System, VGOS) do not properly account…
We describe a new multi-scale deconvolution algorithm that can also be used in multi-frequency mode. The algorithm only affects the minor clean loop. In single-frequency mode, the minor loop of our improved multi-scale algorithm is over an…
Aims : We describe MS-MFS, a multi-scale multi-frequency deconvolution algorithm for wide-band synthesis-imaging, and present imaging results that illustrate the capabilities of the algorithm and the conditions under which it is feasible…
Interferometric closure invariants, constructed from triangular loops of mixed Fourier components, capture calibration-independent information on source morphology. While a complete set of closure invariants is directly obtainable from…
We study the jet kinematics of the blazar S5 0716+714 during its active state in 2003-2004 with multi-epoch VLBI observations. Aims. We present a kinematic analysis of the large-scale (0-12 mas) jet of 0716+714, based on the results of six…
The Caltech-Jodrell Bank very long baseline interferometry (VLBI) Surveys give detailed 5 GHz VLBI images of several hundred milliarcsecond (mas) radio sources, and the full width at half-maximum angular sizes of the corresponding compact…
We introduce an algorithm for the deconvolution of radio synthesis images that accounts for the non-coplanar-baseline effect, allows multiscale reconstruction onto arbitrarily positioned pixel grids, and allows the antenna elements to have…
Super-resolution fluorescence microscopy, with a resolution beyond the diffraction limit of light, has become an indispensable tool to directly visualize biological structures in living cells at a nanometer-scale resolution. Despite…
A new multi-frequency synthesis algorithm for reconstructing images from multi-frequency VLBI data is proposed. The algorithm is based on a generalized maximum-entropy method, and makes it possible to derive an effective spectral correction…
Since its observation in 2019, the first image of a super-massive black hole using Very Long Baseline Interferometry (VLBI) with an Earth-scale baseline has generated much scientific and public interest, including the possible extension of…
A space-based very long baseline interferometry (VLBI) programme, named as the Cosmic Microscope, is proposed to involve dual VLBI telescopes in the space working together with giant ground-based telescopes (e.g., Square Kilometre Array,…
In this series of papers, we present new methods of frequency- and time-dependent instrumental polarization calibration for Very Long Baseline Interferometry (VLBI). In most existing calibration tools and pipelines, it has been assumed that…
We present a new method of time-dependent instrumental polarization calibration for Very Long Baseline Interferometry (VLBI). This method has been implemented in the recently developed polarization calibration pipeline GPCAL. Instrumental…
Radio-astronomical observations are increasingly contaminated by interference, and suppression techniques become essential. A powerful candidate for interference mitigation is adaptive spatial filtering. We study the effect of spatial…
CLEAN, the commonly employed imaging algorithm in radio interferometry, suffers from a number of shortcomings: in its basic version it does not have the concept of diffuse flux, and the common practice of convolving the CLEAN components…
Astronomical imaging using aperture synthesis telescopes requires deconvolution of the point spread function as well as calibration of instrumental and atmospheric effects. In general, such effects are time-variable and vary across the…
Finding a suitable very long baseline (VLBI) interferometer geometry is a key task in planning observations, especially imaging sessions. The main characteristic of the quality of VLBI imaging data is the (u, v)-coverage. In the case when…
The past decade has seen significant advances in wide-field cm-wave very long baseline interferometry (VLBI), which is timely given the wide-area, synoptic survey-driven strategy of major facilities across the electromagnetic spectrum.…
Aims: To formulate, implement, and validate a user-independent release of CLEAN for Fourier-based image reconstruction of hard X-rays flaring sources. Methods: CLEAN is an iterative deconvolution method for radio and hard X-ray solar…
Very long baseline interferometry (VLBI) astrometry is used to determine the three-dimensional position and proper motion of astronomical objects. A typical VLBI astrometric campaign generally includes around ten observations, making it…