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Related papers: First results from the Very Small Array -- I. Obse…

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We report on laboratory test results of the Compact Water Vapor Radiometer (CWVR) prototype for the NSF's Karl G. Jansky Very Large Array (VLA), a five-channel design centered around the 22 GHz water vapor line. Fluctuations in precipitable…

Instrumentation and Methods for Astrophysics · Physics 2019-08-20 Ajay Gill , Robert J. Selina , Bryan J. Butler

The next generation of very long baseline interferometry (VLBI) is stepping into the era of microarcsecond ($\mu$as) astronomy, and pushing astronomy, especially astrometry, to new heights. VLBI with the Square Kilometre Array (SKA),…

Astrophysics of Galaxies · Physics 2024-04-24 Yingjie Li , Ye Xu , Jingjing Li , Shuaibo Bian , Zehao Lin , Chaojie Hao , Dejian Liu

The Very Energetic Radiation Imaging Telescope Array System (VERITAS) represents an important step forward in the study of extreme astrophysical processes in the universe. It combines the power of the atmospheric Cherenkov imaging technique…

Astrophysics · Physics 2008-11-26 T. C. Weekes

The Very Small Array (VSA) has been used to survey the l = 27 to 46 deg, |b|<4 deg region of the Galactic plane at a resolution of 13 arcmin. The survey consists of 44 pointings of the VSA, each with a r.m.s. sensitivity of ~90 mJy/beam.…

The Naval Research Laboratory and the National Radio Astronomy Observatory completed implementation of a low frequency capability on the VLA at 73.8 MHz in 1998. This frequency band offers unprecedented sensitivity (~25 mJy/beam) and…

Precise cosmological measurements are essential for understanding the evolution of the universe and the nature of dark energy. The Five-hundred-meter Aperture Spherical Telescope (FAST), the most sensitive single-dish radio telescope, has…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-23 Jun-Da Pan , Peng-Ju Wu , Guo-Hong Du , Yichao Li , Xin Zhang

We investigate the capabilities of various stages of the SKA to perform world-leading weak gravitational lensing surveys. We outline a way forward to develop the tools needed for pursuing weak lensing in the radio band. We identify the key…

Integrated photonics has reformed our information society by offering on-chip optical signal synthesis, processing and detection with reduced size, weight and power consumption. As such, it has been successfully established in the…

Cosmic Microwave Background (CMB) lensing is a powerful probe of the matter distribution in the Universe. The standard quadratic estimator, which is typically used to measure the lensing signal, is known to be suboptimal for low-noise…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-26 Benjamin Horowitz , Simone Ferraro , Blake D. Sherwin

Realizing the potential of 21 cm tomography to statistically probe the intergalactic medium before and during the Epoch of Reionization requires large telescopes and precise control of systematics. Next-generation telescopes are now being…

Instrumentation and Methods for Astrophysics · Physics 2016-08-17 Joshua S. Dillon , Aaron R. Parsons

The Cherenkov Telescope Array (CTA) will be able to perform unprecedented observations of the transient very high-energy sky. An on-line science alert generation (SAG) pipeline, with a required 30 second latency, will allow the discovery or…

Instrumentation and Methods for Astrophysics · Physics 2019-07-19 Valentina Fioretti , Deivid Ribeiro , Thomas B. Humensky , Andrea Bulgarelli , Gernot Maier , Abelardo Moralejo , Cosimo Nigro

We present results from the first intensive monitoring campaign of a sample of Compact Symmetric Objects (CSOs). We observed seven CSOs at 8.5 GHz over a period of eight months, with an average spacing between observations of 2.7 days. Our…

Astrophysics · Physics 2009-11-06 C. D. Fassnacht , G. B. Taylor

We have used the Very Long Baseline Array (VLBA) and the Very Large Array (VLA) to image Galactic neutral hydrogen in absorption towards four compact extragalactic radio sources with 10 milliarcsecond resolution. Previous VLBA data by…

Astrophysics · Physics 2015-06-24 M. D. Faison , W. M. Goss

The Cherenkov Telescope Array (CTA) is an international initiative to build the next generation ground-based very-high-energy gamma-ray observatory. Full sky coverage will be assured by two arrays, one located on each of the northern and…

Instrumentation and Methods for Astrophysics · Physics 2019-08-14 Maria Concetta Maccarone , Dan Parsons , Markus Gaug , Raquel de los Reyes

In the area of near-field millimeter-wave imaging, the generalized sparse array synthesis (SAS) method is in great demand. The traditional methods usually employ the greedy algorithms, which may have the convergence problem. This paper…

Signal Processing · Electrical Eng. & Systems 2022-08-10 Shuoguang Wang , Shiyong Li , Ahmad Hoorfar , Ke Miao , Guoqiang Zhao , Houjun Sun

Weak gravitational lensing provides a unique method to directly map the dark matter in the universe and measure cosmological parameters. Current weak lensing surveys are limited by the atmospheric seeing from the ground and by the small…

We present a concept study on weak lensing map reconstruction through the cosmic magnification effect in galaxy number density distribution. We propose a minimal variance linear estimator to minimize both the dominant systematical and…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-16 Xinjuan Yang , Pengjie Zhang

The dust feature G159.6--18.5 in the Perseus region has previously been observed with the COSMOSOMAS experiment \citep{Watson:05} on angular scales of $\approx$ 1$^{\circ}$, and was found to exhibit anomalous microwave emission. We present…

The aim of antenna array synthesis is to achieve a desired radiation pattern with the minimum number of antenna elements. In this paper the antenna synthesis problem is studied from a totally new perspective. One of the key principles of…

Information Theory · Computer Science 2008-11-06 Lianlin Li , wenji zhang , Fang Li

Australia Telescope Compact Array (ATCA) observations in sky regions selected to be low in foreground confusion have been used to infer limits on arcmin-scale CMB anisotropy in total intensity and polarization. These deep searches have,…

Astrophysics · Physics 2007-05-23 Ravi Subrahmanyan