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相关论文: Understanding Instrumental Stokes Leakage in Murch…

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The Murchison Widefield Array (MWA), located in Western Australia, is one of the low-frequency precursors of the international Square Kilometre Array (SKA) project. In addition to pursuing its own ambitious science program, it is also a…

Leakage of diffuse polarized emission into Stokes I caused by the polarized primary beam of the instrument might mimic the spectral structure of the 21-cm signal coming from the epoch of reionization (EoR) making their separation difficult.…

The wide adoption of low-frequency radio interferometers as a tool for deeper and higher resolution astronomical observations has revolutionised radio astronomy. Despite their construction from static, relatively simple dipoles, the sheer…

天体物理仪器与方法 · 物理学 2021-02-02 A. Chokshi , J. L. B. Line , N. Barry , D. Ung , D. Kenney , A. McPhail , A. Williams , R. L. Webster

Polarimetric observations are affected by leakage of unpolarized light into the polarization channels, in a way that varies with the angular position of the source relative to the optical axis. The off-axis part of the leakage is often…

天体物理学 · 物理学 2015-05-13 R. I. Reid , A. D. Gray , T. L. Landecker , A. G. Willis

Extraordinarily transmitting arrays are promising candidates for quasi-optical (QO) components due to their high frequency selectivity and beam scanning capabilities owing to the leaky-wave mechanism involved. We show here how by breaking…

We present techniques developed to calibrate and correct Murchison Widefield Array (MWA) low frequency (72-300 MHz) radio observations for polarimetry. The extremely wide field-of-view, excellent instantaneous (u, v)-coverage and…

Detection of the weak cosmological signal from high-redshift hydrogen demands careful data analysis and an understanding of the full instrument signal chain. Here we use the WODEN simulation pipeline to produce realistic data from the…

宇宙学与河外天体物理 · 物理学 2025-01-14 J. L. B. Line , C. M. Trott , N. Barry , D. Null , C. H. Jordan

The coherence properties of mechanical resonators are often limited by multiple unavoidable forms of loss -- including phonon-phonon and phonon-defect scattering -- which result in the scattering of sound into other resonant modes and into…

量子物理 · 物理学 2016-12-30 Xunnong Xu , Seunghwi Kim , Gaurav Bahl , Jacob M. Taylor

We present a broadband map of polarized diffuse emission at 167-198 MHz developed from data from the Murchison Widefield Array (MWA). The map is designed to improve visibility simulation and precision calibration for 21 cm Epoch of…

宇宙学与河外天体物理 · 物理学 2021-11-17 Ruby Byrne , Miguel F. Morales , Bryna Hazelton , Ian Sullivan , Nichole Barry , Christene Lynch , Jack L. B. Line , Daniel C. Jacobs

We present a new approach for correcting instrumental polarization by modeling the non-depolarizing effects of a complex series of optical elements to determine physically realizable Mueller matrices. Provided that the Mueller matrix of the…

天体物理仪器与方法 · 物理学 2022-05-18 Sarah A. Jaeggli , Thomas A. Schad , Lucas A. Tarr , David M. Harrington

We present observations of high-amplitude rapid (2 s) variability toward two bright, compact extragalactic radio sources out of several hundred of the brightest radio sources in one of the 30x30 deg MWA Epoch of Reionization fields using…

Polarimetric studies of pulsars at low radio frequencies provide important observational insights into the pulsar emission mechanism and beam models, and probe the properties of the magneto-ionic interstellar medium (ISM). Aperture arrays…

高能天体物理现象 · 物理学 2019-08-07 Mengyao Xue , S. M. Ord , S. E. Tremblay , N. D. R. Bhat , C. Sobey , B. W. Meyers , S. J. McSweeney , N. A. Swainston

A new high time resolution observing mode for the Murchison Widefield Array (MWA) is described, enabling full polarimetric observations with up to 30.72 MHz of bandwidth and a time resolution of ~0.8 $\mu$s. This mode makes use of a…

天体物理仪器与方法 · 物理学 2020-08-26 S. J. McSweeney , S. M. Ord , N. D. R. Bhat , B. W. Meyers , S. E. Tremblay , J. Jones , B. Crosse , K. R. Smith

The Murchison Widefield Array (MWA) is a low-frequency aperture array capable of high-time and frequency resolution astronomy applications such as pulsar studies. The large field-of-view of the MWA (hundreds of square degrees) can also be…

天体物理仪器与方法 · 物理学 2022-05-18 N. A. Swainston , N. D. R. Bhat , I. S. Morrison , S. J. McSweeney , S. M. Ord , S. E. Tremblay , M. Sokolowski

Reliable detection of bearing faults is essential for maintaining the safety and operational efficiency of rotating machinery. While recent advances in machine learning (ML), particularly deep learning, have shown strong performance in…

机器学习 · 计算机科学 2026-05-18 João Paulo Vieira , Victor Afonso Bauler , Rodrigo Kobashikawa Rosa , Danilo Silva

We provide the first in situ measurements of antenna element (tile) beam shapes of the Murchison Widefield Array (MWA), a low radio-frequency interferometer and an SKA precursor. Most current MWA processing pipelines use an assumed beam…

Leakage of polarized Galactic diffuse emission into total intensity can potentially mimic the 21-cm signal coming from the epoch of reionization (EoR), as both of them might have fluctuating spectral structure. Although we are sensitive to…

天体物理仪器与方法 · 物理学 2018-02-28 K. M. B. Asad , L. V. E. Koopmans , V. Jelić , A. G. de Bruyn , V. N. Pandey , B. K. Gehlot

Next generation radio telescope arrays are being designed and commissioned to accurately measure polarized intensity and rotation measures across the entire sky through deep, wide-field radio interferometric surveys. Radio interferometer…

天体物理仪器与方法 · 物理学 2017-08-02 P. Jagannathan , S. Bhatnagar , U. Rau , A. R. Taylor
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