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Related papers: VLSS Redux: Software Improvements applied to the V…

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The Very Large Array (VLA) has been used in C-configuration to map an area \~0.3 square degrees at 1.4 GHz with 5sigma sensitivities of 0.305, 0.325, 0.380 and 0.450 mJy/beam over four equal subareas. Radio properties are presented for 62…

Recently, considerable interest has focused on variable selection methods in regression situations where the number of predictors, $p$, is large relative to the number of observations, $n$. Two commonly applied variable selection approaches…

Applications · Statistics 2011-04-19 Peter Radchenko , Gareth M. James

Vision Transformers (ViTs) excel in semantic segmentation but demand significant computation, posing challenges for deployment on resource-constrained devices. Existing token pruning methods often overlook fundamental visual data…

Computer Vision and Pattern Recognition · Computer Science 2025-04-28 Yuanbing Ouyang , Yizhuo Liang , Qingpeng Li , Xinfei Guo , Yiming Luo , Di Wu , Hao Wang , Yushan Pan

We report on the first wide-field, very long baseline interferometry (VLBI) survey at 90 cm. The survey area consists of two overlapping 28 deg^2 fields centred on the quasar J0226+3421 and the gravitational lens B0218+357. A total of 618…

Astrophysics · Physics 2009-11-13 Emil Lenc , Mike A. Garrett , Olaf Wucknitz , James M. Anderson , Steven J. Tingay

The Very Small Array (VSA) is a synthesis telescope designed to image faint structures in the cosmic microwave background on degree and sub-degree angular scales. The VSA has key differences from other CMB interferometers with the result…

We present the results of the pilot observations of the Deep Extragalactic VLBI-Optical Survey (DEVOS). Our ultimate aim is to collect information on compact structures in a large sample of extragalactic radio sources (~10000 objects) up to…

Astrophysics · Physics 2009-11-13 L. Mosoni , S. Frey , L. I. Gurvits , M. A. Garrett , S. T. Garrington , Z. I. Tsvetanov

We demonstrate two new approaches that have been developed to aid the production of future hard X-ray catalogs, and specifically to reduce the reliance on human intervention during the detection of faint excesses in maps that also contain…

High Energy Astrophysical Phenomena · Physics 2022-01-19 V. A. Lepingwell , A. J. Bird , S. R. Gunn

The Low Frequency Array (LOFAR) is an ideal instrument to conduct deep extragalactic surveys. It has a large field of view and is sensitive to large scale and compact emission. It is, however, very challenging to synthesize thermal noise…

Operation of an X-ray spectrometer based on a spherical variable line spacing grating is analyzed using dedicated ray-tracing software allowing fast optimization of the grating parameters and spectrometer geometry. The analysis is…

Instrumentation and Detectors · Physics 2010-11-30 V. N. Strocov , T. Schmitt , U. Flechsig , L. Patthey , G. S. Chiuzbăian

I present spherical (https://github.com/m-samland/spherical), a software package and database designed for the ESO VLT/SPHERE high-contrast imager. SPHERE has produced the world's largest archive of direct imaging observations of exoplanets…

Instrumentation and Methods for Astrophysics · Physics 2025-09-11 Matthias Samland

A statistical method for reconstructing large scale structure behind the Zone of Avoidance is presented. It also corrects for shot-noise and for redshift distortion in galaxy surveys. The galaxy distribution is expanded in an orthogonal set…

Astrophysics · Physics 2007-05-23 Ofer Lahav

The sky subtraction performances of multi-fiber spectrographs are discussed, analysing in detail the case of the OPTOPUS system at the 3.6 meter ESO telescope at La Silla. A standard technique, based on flat-fields obtained with a uniformly…

Astrophysics · Physics 2009-10-22 C. Lissandrini , S. Cristiani , F. La Franca

In this work, we introduce a variable window size (VWS) spatial smoothing framework that enhances coarray-based direction of arrival (DOA) estimation for sparse linear arrays. By compressing the smoothing aperture, the proposed VWS Coarray…

Machine Learning · Computer Science 2025-12-29 Wesley S. Leite , Rodrigo C. de Lamare , Yuriy Zakharov , Wei Liu , Martin Haardt

The Low Frequency Array (LOFAR) radio telescope is an international aperture synthesis radio telescope used to study the Universe at low frequencies. One of the goals of the LOFAR telescope is to conduct deep wide-field surveys. Here we…

Instrumentation and Methods for Astrophysics · Physics 2018-04-11 A. P. Mechev , J. B. R. Oonk , A. Danezi , T. W. Shimwell , C. Schrijvers , H. T. Intema , A. Plaat , H. J. A. Röttgering

In Kato and Uemura (2012), we introduced the Least Absolute Shrinkage and Selection Operator (Lasso) method, a kind of sparse modeling, to study frequency structures of variable stars. A very high frequency resolution was achieved compared…

Solar and Stellar Astrophysics · Physics 2022-01-20 Taichi Kato

The impressive performance of Large Language Models (LLMs) across various natural language processing tasks comes at the cost of vast computational resources and storage requirements. One-shot pruning techniques offer a way to alleviate…

Machine Learning · Computer Science 2025-09-09 Xiang Meng , Kayhan Behdin , Haoyue Wang , Rahul Mazumder

A new generation of wide-field radio interferometers designed for 21-cm surveys is being built as drift scan instruments allowing them to observe large fractions of the sky. With large numbers of antennas and frequency channels the enormous…

Instrumentation and Methods for Astrophysics · Physics 2017-10-10 Philippe Berger , Niels Oppermann , Ue-Li Pen , J. Richard Shaw

Observational astronomy has undergone a significant transformation driven by large-scale surveys, such as the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) Survey, the Sloan Digital Sky Survey (SDSS), and the Gaia…

Instrumentation and Methods for Astrophysics · Physics 2025-08-14 Bradley D. Hutchinson , Catherine A. Pilachowski , Christian I. Johnson

In this paper we presented the modified algorithm for astrometric reduction of the wide-field images. This algorithm is based on the iterative using of the method of ordinary least squares (OLS) and statistical Student t-criterion. The…

Instrumentation and Methods for Astrophysics · Physics 2019-04-10 Volodymyr Akhmetov , Sergii Khlamov , Vladislav Khramtsov , Artem Dmytrenko

The ambitious scientific goals of the SKA require a matching capability for calibration of atmospheric propagation errors, which contaminate the observed signals. We demonstrate a scheme for correcting the direction-dependent ionospheric…

Instrumentation and Methods for Astrophysics · Physics 2018-07-18 Maria Rioja , Richard Dodson , Thomas Franzen