ﻻ يوجد ملخص باللغة العربية
We investigate the imaging performance of an interferometric array in the case of wide field, high resolution, narrow band, snapshot imaging. We find that, when uv-cell sizes are sufficiently small (ie. image sizes are sufficiently large), each instantaneous visibility record is gridded into its own uv-cell. This holds even for dense arrays, like the core of the next generation VLA. In this particular, application, Uniform weighting of the gridded visibilities approaches Natural weighting, with its often deleterious consequences on the resulting synthesized beam. For a core-dominated array, we show that the resulting image noise is highly correlated on scales comparable to the spatial frequencies of the core baselines. In general, this study accentuates the fact that, for imaging applications that require high resolution (Plains array and greater), many of the core antennas can be employed as a separate subarray for low resolution science, without sacrificing the quality of the high resolution science.
The limits to the angular resolution achievable with conventional ground-based telescopes are unchanged over 70 years. Atmospheric turbulence limits image quality to typically ~1 arcsec in practice. We have developed a new concept of ground-based ima
GravityCam is a new concept of ground-based imaging instrument capable of delivering significantly sharper images from the ground than is normally possible without adaptive optics. Advances in optical and near infrared imaging technologies allow imag
With the development of modern radio interferometers, wide-field continuum surveys have been planned and undertaken, for which accurate wide-field imaging methods are essential. Based on the widely-used W-stacking method, we propose a new wide-field
We present a wide field, sub-arcminute resolution VLA image of the Galactic Center region at 330 MHz. With a resolution of ~ 7 X 12 and an RMS noise of 1.6 mJy/beam, this image represents a significant increase in resolution and sensitivity over the
Binospec is a high throughput, 370 to 1000 nm, imaging spectrograph that addresses two adjacent 8 by 15 fields of view. Binospec was commissioned in late 2017 at the f/5 focus of the 6.5m MMT and is now available to all MMT observers. Aperture masks