English
Related papers

Related papers: LBCS: the LOFAR Long-Baseline Calibrator Survey

200 papers

In the mHz gravitational-wave band, galactic ultra-compact binaries (UCBs) are continuous sources emitting at near-constant frequency. The signals from many of these galactic binaries will be sufficiently strong to be detectable by the…

Instrumentation and Methods for Astrophysics · Physics 2018-08-15 Tyson B. Littenberg

Multi-layer diffuse correlation spectroscopy (DCS) models have been developed to reduce the contamination of superficial signals in cerebral blood flow index (CBFi) measurements. However, a systematic comparison of these models and clear…

Medical Physics · Physics 2025-07-30 Mingliang Pan , Quan Wang , Yuanzhe Zhang , David Day-Uei Li

Four close radio sources in the International Celestial Reference Frame (ICRF) catalog were observed using phase referencing with the VLBA at 43, 23 and 8.6 GHz, and with VERA at 23 GHz over a one year period. The goal was to determine the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Ed Fomalont , Kenneth Johnston , Alan Fey , Dave Boboltz , Tamoaki Oyama , Mareki Honma

Many scientific goals for the Dark Energy Survey (DES) require calibration of optical/NIR broadband $b = grizY$ photometry that is stable in time and uniform over the celestial sky to one percent or better. It is also necessary to limit to…

Using the latest upper limits on the 21-cm power spectrum at $z\approx9.1$ from the Low Frequency Array (LOFAR), we explore regions of parameter space which are inconsistent with the data. We use 21CMMC, a Monte Carlo Markov Chain sampler…

The Low Frequency Array (LOFAR) Two-metre Sky Survey (LoTSS) is a low-frequency radio continuum survey of the Northern sky at an unparalleled resolution and sensitivity. In order to fully exploit this huge dataset and those produced by the…

Extending terrestrial networks into low-altitude airspace is a practical way to support aerial services, and accurate low-altitude radio maps are essential for characterizing terrestrial base station (BS) coverage and guiding system design.…

Signal Processing · Electrical Eng. & Systems 2026-05-25 Bowen Li , Haotian Zhang , Mu Jia , Junting Chen , Nikolaos Pappas

Self-calibration methods with the CLEAN algorithm have been widely employed in Very Long Baseline Interferometry (VLBI) data processing in order to correct antenna-based amplitude and phase corruptions present in the data. However, human…

Instrumentation and Methods for Astrophysics · Physics 2024-10-02 Jong-Seo Kim , Aleksei S. Nikonov , Jakob Roth , Torsten A. Ensslin , Michael Janssen , Philipp Arras , Hendrik Mueller , Andrei P. Lobanov

The development of new phased array systems in radio astronomy, as the low frequency array (LOFAR) and the square kilometre array (SKA), formed of a large number of small and flexible elementary antennas, has led to significant challenges.…

The Caltech-Jodrell Bank very long baseline interferometry (VLBI) Surveys give detailed 5 GHz VLBI images of several hundred milliarcsecond (mas) radio sources, and the full width at half-maximum angular sizes of the corresponding compact…

Astrophysics · Physics 2009-11-13 J. C. Jackson

We present multi-frequency scatter broadening evolution of 29 pulsars observed with the LOw Frequency ARray (LOFAR) and Long Wavelength Array (LWA). We conducted new observations using LOFAR Low Band Antennae (LBA) as well as utilized the…

High Energy Astrophysical Phenomena · Physics 2019-06-26 M. A. Krishnakumar , Yogesh Maan , Bhal Chandra Joshi , P. K. Manoharan

The exact location of the gamma-ray emitting region in blazars is still controversial. In order to attack this problem we present first results of a cross-correlation analysis between radio (11 cm to 0.8 mm wavelength, F-GAMMA program) and…

Broadband quantum noise reduction can be achieved in gravitational wave detectors by injecting frequency dependent squeezed light into the the dark port of the interferometer. This frequency dependent squeezing can be generated by combining…

Quantum Physics · Physics 2019-10-23 Jacob L. Beckey , Yiqiu Ma , Vincent Boyer , Haixing Miao

The CONT14 campaign with state-of-the-art VLBI data has observed the source 0642+449 with about one thousand observables each day during a continuous observing period of fifteen days, providing tens of thousands of closure delays---the sum…

Instrumentation and Methods for Astrophysics · Physics 2016-11-09 Ming H. Xu , Robert Heinkelmann , James M. Anderson , Julian Mora-Diaz , Harald Schuh , Guang L. Wang

The paper presents the results of the largest to date VLBI absolute astrometry campaign of observations of 13,645 radio sources with the Very Long Baseline Array (VLBA). Of them, 7220 have been detected, including 6755 target sources that…

Instrumentation and Methods for Astrophysics · Physics 2020-12-16 Leonid Petrov

In an attempt to constrain and understand the emission mechanism of gamma rays, we perform a cross-correlation analysis of 15 blazars using light curves in millimetre, optical and gamma rays. We use discrete correlation function and…

High Energy Astrophysical Phenomena · Physics 2015-12-15 V. Ramakrishnan , T. Hovatta , M. Tornikoski , K. Nilsson , E. Lindfors , M. Baloković , A. Lähteenmäki , R. Reinthal , L. Takalo

The Largest Cluster Statistics\,(LCS) analysis of the redshifted 21\,cm maps has been demonstrated to be an efficient and robust method for following the time evolution of the largest ionized regions\,(LIRs) during the Epoch of…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-28 Samit Kumar Pal , Saswata Dasgupta , Abhirup Datta , Suman Majumdar , Satadru Bag , Prakash Sarkar

The aim of this study is to probe the sub-mJy polarized source population with LOFAR. We present the method used to stack LOFAR polarization datasets, the resulting catalog of polarized sources, and the derived polarized source counts. The…

We report on a traceable calibration system for a 3500mm-long console that carries a measurement system for inspecting the diameter of a circular reactor chassis. The system uses two single-pass laser interferometers with homodyne fringe…

Instrumentation and Detectors · Physics 2019-05-03 Simon Rerucha , Bretislav Mikel , Zdenek Matej , Ondrej Herman , Miroslava Hola , Michal Jelinek , Petr Jedlicka , Ondrej Cip , Josef Lazar

Before and after every 12 hour synthesis observation, the Molonglo Observatory Synthesis Telescope (MOST) measures the flux densities of ~5 compact extragalactic radio sources, chosen from a list of 55 calibrators. From 1984 to 1996, the…

Astrophysics · Physics 2015-06-24 B. M. Gaensler , R. W. Hunstead
‹ Prev 1 8 9 10 Next ›