English
Related papers

Related papers: New results from LOFAR

200 papers

A fraction of galaxy clusters harbor diffuse radio sources known as radio halos. The currently adopted scenario for their formation is based on second-order Fermi re-acceleration of seed electrons that is driven by merger-driven turbulence…

We are performing two complementary pilot pulsar surveys as part of LOFAR commissioning. The LOFAR Pilot Pulsar Survey (LPPS) is a shallow all-sky survey using an incoherent combination of LOFAR stations. The LOFAR Tied-Array Survey (LOTAS)…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Thijs Coenen , The LOFAR Pulsar Working Group

A number of hardware upgrades for the Low-Frequency Array (LOFAR) are currently under development. These upgrades are collectively referred to as the LOFAR 2.0 upgrade. The first stage of LOFAR 2.0 will introduce a distributed clock signal…

Instrumentation and Methods for Astrophysics · Physics 2021-08-11 H. W. Edler , F. de Gasperin , D. Rafferty

We have conducted a deep survey (with a central rms of $55\mu\textrm{Jy}$) with the LOw Frequency ARray (LOFAR) at 120-168 MHz of the Bo\"otes field, with an angular resolution of $3.98^{''}\times6.45^{''}$, and obtained a sample of 10091…

The technique of Faraday tomography is a key tool for the study of magnetised plasmas in the new era of broadband radio polarisation observations. In particular, observations at metre-wavelengths provide significantly better Faraday depth…

High Energy Astrophysical Phenomena · Physics 2018-12-03 Shane P. O'Sullivan , M. Brüggen , C. L. Van Eck , M. J. Hardcastle , M. Haverkorn , T. W. Shimwell , C. Tasse , V. Vacca , C. Horellou , G. Heald

The Large European Array for Pulsars (LEAP) is an experiment that harvests the collective power of Europe's largest radio telescopes in order to increase the sensitivity of high-precision pulsar timing. As part of the ongoing effort of the…

Instrumentation and Methods for Astrophysics · Physics 2016-01-27 C. G. Bassa , G. H. Janssen , R. Karuppusamy , M. Kramer , K. J. Lee , K. Liu , J. McKee , D. Perrodin , M. Purver , S. Sanidas , R. Smits , B. W. Stappers

Our understanding of the universe relies mostly on electromagnetism. As photons are the messengers, fundamental physics is concerned in testing their properties. Photon mass upper limits have been earlier set through pulsar observations,…

Instrumentation and Methods for Astrophysics · Physics 2016-12-30 Mark J. Bentum , Luca Bonetti , Alessandro D. A. M. Spallicci

We present radio observations of the most slowly rotating known radio pulsar PSR J0250+5854. With a 23.5 s period, it is close, or even beyond, the $P$-$\dot{P}$ diagram region thought to be occupied by active pulsars. The simultaneous…

LOFAR is a new and innovative effort to build a radio-telescope operating at the multi-meter wavelength spectral window. One of the most exciting applications of LOFAR will be the search for redshifted 21-cm line emission from the Epoch of…

Instrumentation and Methods for Astrophysics · Physics 2010-08-26 Panagiotis Labropoulos , the LOFAR EoR KSP team

During February 2016, CSIRO Astronomy and Space Science and the Max-Planck-Institute for Radio Astronomy installed, commissioned and carried out science observations with a phased array feed (PAF) receiver system on the 64m diameter Parkes…

Instrumentation and Methods for Astrophysics · Physics 2017-07-19 X. Deng , A. P. Chippendale , G. Hobbs , S. Johnston , S. Dai , D. George , M. Kramer , R. Karuppusamy , M. Malenta , L. Spitler , T. Tzioumis , G. Wieching

Observations of interplanetary scintillation (IPS - the scintillation of compact radio sources due to density variations in the solar wind) enable the velocity of the solar wind to be determined, and its bulk density to be estimated,…

Solar and Stellar Astrophysics · Physics 2022-10-06 R. A. Fallows , K. Iwai , B. V. Jackson , P. Zhang , M. M. Bisi , P. Zucca

Modern astronomical data processing requires complex software pipelines to process ever growing datasets. For radio astronomy, these pipelines have become so large that they need to be distributed across a computational cluster. This makes…

Instrumentation and Methods for Astrophysics · Physics 2018-07-17 Alexandar P. Mechev , Aske Plaat , J. B. Raymond Oonk , Huib T. Intema , Huub J. A. Röttgering

We report on the multi-frequency timing observations of 21 pulsars discovered in the LOFAR Tied-Array All-Sky Survey (LOTAAS). The timing data were taken at central frequencies of 149 MHz (LOFAR) as well as 334 and 1532 MHz (Lovell…

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

We discuss a possible generation of radio bursts preceding final stages of binary neutron star mergings which can be accompanied by short gamma-ray bursts. Detection of such bursts appear to be advantageous in the low-frequency radio band…

High Energy Astrophysical Phenomena · Physics 2010-04-29 M. S. Pshirkov , K. A. Postnov

The quiet solar corona emits meter-wave thermal bremsstrahlung. Coronal radio emission can only propagate above that radius, $R_\omega$, where the local plasma frequency eqals the observing frequency. The radio interferometer LOw Frequency…

Solar and Stellar Astrophysics · Physics 2018-06-13 C. Vocks , G. Mann , F. Breitling , M. M. Bisi , B. Dabrowski , R. Fallows , P. T. Gallagher , A. Krankowski , J. Magdalenic , C. Marque , D. Morosan , H. Rucker

Low radio frequency surveys are important for testing unified models of radio-loud quasars and radio galaxies. Intrinsically similar sources that are randomly oriented on the sky will have different projected linear sizes. Measuring the…

We explore the low-frequency radio properties of the sources in the Fanaroff-Riley class 0 catalog (FR0CAT) as seen by the LOw Frequency ARray (LOFAR) observations at 150 MHz. This sample includes 104 compact radio active galactic nuclei…

The high-frequency radio sky is bursting with synchrotron transients from massive stellar explosions and accretion events, but the low-frequency radio sky has so far been quiet beyond the Galactic pulsar population and the long-term…

High Energy Astrophysical Phenomena · Physics 2025-03-12 N. Hurley-Walker , X. Zhang , A. Bahramian , S. J. McSweeney , T. N. O'Doherty , P. J. Hancock , J. S. Morgan , G. E. Anderson , G. H. Heald , T. J. Galvin