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Related papers: Lofar, E-Lofar and Low-Frequency Vlbi

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We describe a new method which achieves high precision Very Long Baseline Interferometry (VLBI) astrometry in observations at millimeter wavelengths. It combines fast frequency-switching observations, to correct for the dominant…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 Maria J. Rioja , Richard Dodson

With the establishment of the AUT University 12m radio telescope at Warkworth, New Zealand has now become a part of the international Very Long Baseline Interferometry (VLBI) community. A major product of VLBI observations are images in the…

Instrumentation and Methods for Astrophysics · Physics 2011-10-26 Stuart Weston , Tim Natusch , Sergei Gulyaev

The new generation of high-resolution broad-band radio telescopes, like the Low Frequency Array (LOFAR), produces, depending on the level of compression, between 1 to 10 TB of data per hour after correlation. Such a large amount of…

Instrumentation and Methods for Astrophysics · Physics 2019-11-12 A. Drabent , M. Hoeft , A. P. Mechev , J. B. R. Oonk , T. W. Shimwell , F. Sweijen , A. Danezi , C. Schrijvers , C. Manzano , O. Tsigenov , R. -J. Dettmar , M. Brüggen , D. J. Schwarz

Very long baseline interferometry (VLBI) provides the highest-resolution images in astronomy. The sharpest resolution is nominally achieved at the highest frequencies, but as the observing frequency increases so too does the atmospheric…

The Seoul Radio Astronomy Observatory (SRAO) operates a 6.1-meter radio telescope on the Gwanak campus of Seoul National University. We present the efforts to reform SRAO to a Very Long Baseline Interferometry (VLBI) station, motivated by…

Instrumentation and Methods for Astrophysics · Physics 2023-01-30 Naeun Shin , Yong-Sun Park , Do-Young Byun , Jinguk Seo , Dongkok Kim , Cheulhong Min , Hyunwoo Kang , Keiichi Asada , Wen-Ping Lo , Sascha Trippe

We present parameterized broadband spectral models valid at frequencies between 30-300 MHz for six bright radio sources selected from the 3C survey, spread in Right Ascension from 0-24 hours. For each source, data from the literature are…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 Anna M. M. Scaife , George H. Heald

We have conducted two pilot surveys for radio pulsars and fast transients with the Low-Frequency Array (LOFAR) around 140 MHz and here report on the first low-frequency fast-radio burst limit and the discovery of two new pulsars. The first…

Radio pulses emitted in the atmosphere during the air shower development of high-energy primary cosmic rays were measured during the late 1960ies in the frequency range from 2 MHz to 520 MHz. Mainly due to difficulties with radio…

Astrophysics · Physics 2007-05-23 LOPES Collaboration , A. Horneffer

Very Long Baseline Interferometry (VLBI) at radio wavelengths can provide astrometry accurate to 10 micro-arcseconds or better (i.e. better than the target GAIA accuracy) without being limited by dust obscuration. This means that unlike…

In this paper, I present the likely technological development of VLBI, and its impact on the astronomical community over the next 1-5 years. VLBI is currently poised to take advantage of the rapid development in commercial off-the-shelf…

Astrophysics · Physics 2007-05-23 M. A. Garrett

A space-based very long baseline interferometry (VLBI) programme, named as the Cosmic Microscope, is proposed to involve dual VLBI telescopes in the space working together with giant ground-based telescopes (e.g., Square Kilometre Array,…

Instrumentation and Methods for Astrophysics · Physics 2022-05-19 Tao An , Sumit Jaiswal , Prashanth Mohan , Zhen Zhao , Baoqiang Lao

The Large Area Telescope (LAT) instrument onboard GLAST offers a tremendous opportunity for future blazar studies. In order to fully benefit from its capabilities and to maximize the scientific return from the LAT, it is of great importance…

Astrophysics · Physics 2009-06-23 L. Fuhrmann , J. A. Zensus , T. P. Krichbaum , E. Angelakis , A. C. S. Readhead

The polarization properties of radio sources at very low frequencies (<200 MHz) have not been widely measured, but the new generation of low-frequency radio telescopes, including the Low Frequency Array (LOFAR: a Square Kilometre Array Low…

The design and development process for the Square Kilometre Array (SKA) radio telescope, the Low Frequency Aperture Array component, was progressed during the SKA pre-construction phase by an international consortium, with the goal of…

LOFAR offers the unique capability of observing pulsars across the 10-240 MHz frequency range with a fractional bandwidth of roughly 50%. This spectral range is well-suited for studying the frequency evolution of pulse profile morphology…

The Shanghai Astronomical Observatory (SHAO) of the Chinese Academy of Sciences (CAS) is studying a space VLBI (Very Long Baseline Interferometer) program. The ultimate objective of the program is to image the immediate vicinity of the…

Instrumentation and Methods for Astrophysics · Physics 2014-07-01 Xiaoyu Hong , Zhiqiang Shen , Tao An , Qinghui Liu , the Chinese Space VLBI Array team

The calibration and analysis of polarization observations in Very Long Baseline Interferometry (VLBI) requires the use of specific algorithms that suffer from several limitations, closely related to assumptions in the data properties that…

Instrumentation and Methods for Astrophysics · Physics 2021-02-10 Ivan Marti-Vidal , Alejandro Mus , Michael Janssen , Pablo de Vicente , Javier Gonzalez

We have obtained 8.4 GHz VLBA observations of a 31-GHz complete sample of ~100 sources between 10 and 100 mJy. The main goals of these observations are: to determine the angular size, radio spectra and identification for a weak sample of…

Astrophysics · Physics 2008-06-19 W. A. Majid , E. B. Fomalont , D. S. Bagri

Very long baseline interferometry (VLBI) enables high-angular-resolution observations in astronomy and geodesy by synthesizing a virtual telescope with baselines spanning hundreds to thousands of kilometres. Achieving high instrumental…

Instrumentation and Methods for Astrophysics · Physics 2026-05-28 Minji Hyun , Changmin Ahn , Junyong Choi , Jihoon Baek , Woosong Jeong , Do-Heung Je , Do-Young Byun , Jan Wagner , Myoung-Sun Heo , Taehyun Jung , Jungwon Kim

In this paper we present the results of a survey for radio transients using data obtained from the Very Large Array archive. We have reduced, using a pipeline procedure, 5037 observations of the most common pointings - i.e. the calibrator…