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Related papers: Long baseline experiments with LOFAR

200 papers

We present the results of an HST and ground-based imaging study of a complete 3C sample of z ~ 1 sources, including 5 quasars and 5 radio galaxies. We have resolved continuum structure around all of our quasars in the WFPC2 images and in…

Astrophysics · Physics 2009-10-30 Susan E. Ridgway , Alan Stockton

Further investigation of data on quasars, especially in the ultraviolet band, yields an amazingly coherent narrative which we present in this paper. Quasars are characterised by strong continuum emission and redshifted emission and…

Astrophysics of Galaxies · Physics 2017-12-07 Nimisha G. Kantharia

LOFAR, the "low-frequency array", will be one of the first in a new generation of radio telescopes and Square Kilometer Array (SKA) pathfinders that are highly flexible in capability because they are largely software driven. LOFAR will not…

Instrumentation and Methods for Astrophysics · Physics 2009-03-10 J. W. T. Hessels , B. W. Stappers , J. van Leeuwen , LOFAR Transients Key Science Project

The cosmic infrared background (CIB) is a powerful probe of large-scale structure across a very large redshift range, and consists of unresolved redshifted infrared emission from dusty galaxies. It can be used to study the astrophysics of…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-02 Daniel Lenz , Olivier Doré , Guilaine Lagache

BL Lacertae (Lac) objects that are detected at very-high energies (VHE) are of fundamental importance to study multiple astrophysical processes, including the physics of jets, the properties of the extragalactic background light and the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Michele Fumagalli , Miroslava Dessauges-Zavadsky , Amy Furniss , J. Xavier Prochaska , David Williams , Kyle Kaplan , Matthew Hogan

Recent work has successfully achieved sub-arcsecond wide-field imaging with high-band observations from the Low Frequency Array (LOFAR). However, the scalability of this work remains limited due to the need for manual intervention, poor…

The physical nature of the material responsible for the high--velocity, broad-absorption line features seen in a small fraction of quasar spectra has been the subject of debate since their discovery. This has been especially compounded by…

Astrophysics · Physics 2009-10-30 Geraint F. Lewis , Kunegunda E. Belle

This paper provides full sky maps of foreground emission in all WMAP channels, with very low residual contamination from the Cosmic Microwave Background (CMB) anisotropies and controlled level of instrumental noise. Foreground maps are…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-25 Tuhin Ghosh , Jacques Delabrouille , Mathieu Remazeilles , Jean-Francois Cardoso , Tarun Souradeep

Low-power radio sources dominate the radio sky. They tend to be small in size and core-dominated, but the origin of their properties and the evolution of their radio plasma are not well constrained. Interestingly, there is mounting evidence…

Astrophysics of Galaxies · Physics 2020-02-19 Sarrvesh S. Sridhar , Raffaella Morganti , Kristina Nyland , Bradley S. Frank , Jeremy Harwood , Tom Oosterloo

We present preliminary results from a reverberation mapping program to measure the Broad Line Region size in high-redshift, high-luminosity quasars. The observations are carried out at the Hobby-Eberly Telescope and at the Wise Observatory.…

Astrophysics · Physics 2007-05-23 Shai Kaspi , Hagai Netzer , Dan Maoz , Ohad Shemmer , W. N. Brandt , Donald P. Schneider

The quasar 3C 279 is one of the best-studied flat spectrum radio quasars. It is located at a comparatively large redshift of z=0.536: E>100 GeV observations of such distant sources were until recently impossible both due to the expected…

We have carried out a survey to search for hidden blazars in a sample of $z{\sim}2$ radio-loud quasars. The idea is based on our prediction that we should be able to see large CIV line variability not associated with observed continuum…

Astrophysics · Physics 2007-05-23 Feng Ma

The FIRBACK project is a collaboration of eight institutes aimed at using long wavelength surveys with ISO to uncover the nature of the Cosmic Far-Infrared Background. We have surveyed nearly 4 sq. deg. in three regions in the northern and…

We explore the requirements for a Lyman-alpha forest (LyaF) survey designed to measure the angular diameter distance and Hubble parameter at 2~<z~<4 using the standard ruler provided by baryonic acoustic oscillations (BAO). The goal would…

Astrophysics · Physics 2008-11-26 Patrick McDonald , Daniel Eisenstein

The uncharted territory of the high-redshift ($z\gtrsim3$) Universe holds the key to understand the evolution of quasars. In an attempt to identify the most extreme members of the quasar population, i.e., blazars, we have carried out a…

High Energy Astrophysical Phenomena · Physics 2020-07-22 Vaidehi S. Paliya , M. Ajello , H. -M. Cao , M. Giroletti , Amanpreet Kaur , Greg Madejski , Benoit Lott , D. Hartmann

"High-resolution", or "long-baseline", science with the SKA and its precursors covers a broad range of topics in astrophysics. In several research areas, the coupling between improved brightness sensitivity of the SKA and a sub-arcsecond…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 A. P. Lobanov

We present a milliarcsecond-resolution radio survey of 17 high-redshift (4 < z < 5.4) blazar candidates observed with the European Very Long Baseline Interferometry (VLBI) Network at 5 GHz. The primary objective of this study was to…

The FIRBACK (Far Infrared BACKground) survey is one of the deepest imaging surveys carried out at 170 microns with ISOPHOT onboard ISO, and is aimed at the study of the structure of the Cosmic Far Infrared Background. This paper provides…

Blazars are a sub-class of quasars with Doppler boosted jets oriented close to the line of sight, and thus efficient probes of supermassive black hole growth and their environment, especially at high redshifts. Here we report on Very Long…

In this paper we introduce a reliable, fully automated and fast algorithm to detect extended extragalactic radio sources (cluster of galaxies, filaments) in existing and forthcoming surveys (like LOFAR and SKA). The proposed solution is…

Instrumentation and Methods for Astrophysics · Physics 2018-09-11 Claudio Gheller , Franco Vazza , Annalisa Bonafede