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Related papers: Systematic effects in LOFAR data: A unified calibr…

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We present a deep, low-frequency radio continuum study of the nearby Fanaroff--Riley class I (FR I) radio galaxy 3C 31 using a combination of LOw Frequency ARray (LOFAR; 30--85 and 115--178 MHz), Very Large Array (VLA; 290--420 MHz),…

Radio pulses from pulsars are affected by plasma dispersion, which results in a frequency-dependent propagation delay. Variations in the magnitude of this effect lead to an additional source of red noise in pulsar timing experiments,…

The standing waves existed in radio telescope data are primarily due to reflections among the instruments, which significantly impact the spectrum quality of the Five-hundred-meter Aperture Spherical radio Telescope (FAST). Eliminating…

Instrumentation and Methods for Astrophysics · Physics 2025-01-09 Chen Xu , Jie Wang , Yingjie Jing , Fujia Li , Hengqian Gan , Ziming Liu , Tiantian Liang , Qingze Chen , Zerui Liu , Zhipeng Hou , Hao Hu , Huijie Hu , Shijie Huang , Peng Jiang , Chuan-Peng Zhang , Yan Zhu

We present the first deep (72 hours of observations) radio image of the Euclid Deep Field North (EDFN) obtained with the LOw-Frequency ARray (LOFAR) High Band Antenna (HBA) at 144 MHz. The EDFN is the latest addition to the LOFAR Two-Metre…

High-resolution astronomical imaging at sub-GHz radio frequencies has been available for more than 15 years, with the VLA at 74 and 330 MHz, and the GMRT at 150, 240, 330 and 610 MHz. Recent developments include wide-bandwidth upgrades for…

Instrumentation and Methods for Astrophysics · Physics 2014-02-21 H. T. Intema

Global 21-cm experiments require exquisitely precise calibration of the measurement systems in order to separate the weak 21-cm signal from Galactic and extragalactic foregrounds as well as instrumental systematics. Hitherto, experiments…

Instrumentation and Methods for Astrophysics · Physics 2022-04-27 Jishnu N. Thekkeppattu , Benjamin McKinley , Cathryn M. Trott , Jake Jones , Daniel C. X. Ung

The Laser Interferometer Space Antenna (LISA) is expected to provide the largest observational sample of binary systems of faint sub-solar mass compact objects, in particular white-dwarfs, whose radiation is monochromatic over most of the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 A. Vecchio , E. D. L. Wickham

The LOw Frequency ARray - LOFAR - is a new radio interferometer designed with emphasis on flexible digital hardware instead of mechanical solutions. The array elements, so-called stations, are located in the Netherlands and in neighbouring…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 Maciej Serylak , Aris Karastergiou , Chris Williams , Wesley Armour , Michael Giles , the LOFAR Pulsar Working Group

The radio astronomy community is currently building a number of phased array telescopes. The calibration of these telescopes is hampered by the fact that covariances of signals from closely spaced antennas are sensitive to noise coupling…

Instrumentation and Methods for Astrophysics · Physics 2010-03-15 Stefan J. Wijnholds , Alle-Jan van der Veen

Precise knowledge of a laser's wavelength is crucial for applications from spectroscopy to telecommunications. Here we present a wavemeter which operates on the Talbot effect. Tone parameter extraction algorithms are used to retrieve the…

Instrumentation and Detectors · Physics 2019-10-02 Ningren Han , Gavin N. West , Amir H. Atabaki , David Burghoff , Rajeev J. Ram

Many astronomical questions require deep, wide-field observations at low radio frequencies. Phased arrays like LOFAR and SKA-low are designed for this, but have inherently unstable element gains, leading to time, frequency and…

Instrumentation and Methods for Astrophysics · Physics 2025-08-28 S. A. Brackenhoff , A. R. Offringa , M. Mevius , L. V. E. Koopmans , J. K. Chege , E. Ceccotti , C. Höfer , L. Gao , S. Ghosh , F. G. Mertens , S. Munshi

Radio Frequency Interference (RFI) corrupts astronomical measurements, thus affecting the performance of radio telescopes. To address this problem, supervised segmentation models have been proposed as candidate solutions to RFI detection.…

Instrumentation and Methods for Astrophysics · Physics 2022-10-12 Michael Mesarcik , Albert-Jan Boonstra , Elena Ranguelova , Rob V. van Nieuwpoort

This study evaluates the impact of Starlink satellites on low-frequency radio astronomy below 100 MHz, focusing on challenges on data processing and scientific goals. We conducted 40 hours of imaging observations using NenuFAR, in the…

Photonic integration offers the potential to bring complex high-performance optical systems to the form factor of a compact semiconductor chip. However, the range of system functions accessible critically depends on the extent to which…

Our aim is to assess the benefits and limitations of using the redundant visibility information in regular phased array systems for improving the calibration. Regular arrays offer the possibility to use redundant visibility information to…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Parisa Noorishad , Stefan J. Wijnholds , Arnold van Ardenne , Thijs van der Hulst

The next generation of radio surveys is going to be transformative for cosmology and other aspects of our understanding of astrophysics. Realistic simulations of radio observations are essential for the design and planning of radio surveys.…

Instrumentation and Methods for Astrophysics · Physics 2025-07-30 Tobias Vičánek Martínez , Henrik W. Edler , Marcus Brüggen

Regular magnetic field structures can be derived from the Faraday rotation measures (RM) of polarized background sources observable at 1.4 GHz with the SKA. At lower frequencies ($<250$ MHz) polarimetry of radio sources with the Low…

Cosmology and Nongalactic Astrophysics · Physics 2009-04-20 Tigran G. Arshakian , Rainer Beck

The next generation of galaxy surveys has the potential to substantially deepen our understanding of the Universe. This potential hinges on our ability to rigorously address systematic uncertainties. Until now, diagnosing systematic effects…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-18 Tristan Hoellinger , Florent Leclercq

Some galaxy clusters contain non-thermal synchrotron emitting plasma permeating the intracluster medium (ICM). The spectral properties of this radio emission are not well characterized at decameter wavelengths ({\nu} < 30 MHz), primarily…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-10 C. Groeneveld , R. J. van Weeren , A. Botteon , R. Cassano , F. de Gasperin , E. Osinga , G. Brunetti , H. J. A. Röttgering

Radio observations of young stellar objects (YSOs) enable the study of ionised plasma outflows from young protostars via their free-free radiation. Previous studies of the low-mass young system T Tau have used radio observations to model…