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Related papers: New results from LOFAR

200 papers

While the Low Frequency Array (LOFAR) is still in its commissioning phase, early science results are starting to emerge. Two nearby galaxies, M51 and NGC4631, have been observed as part of the Magnetism Key Science Project's (MKSP) effort…

Ultra-low frequency observations (<100 MHz) are particularly challenging because they are usually performed in a low signal-to-noise ratio regime due to the high sky temperature and because of ionospheric disturbances whose effects are…

The LOw-Frequency ARray (LOFAR) has recently conducted a survey (LOFAR Tied-Array All-sky Survey; LOTAAS) for pulsars in the Northern hemisphere that resulted in discoveries of 73 new pulsars. For the purpose of studying the properties of…

High Energy Astrophysical Phenomena · Physics 2021-05-05 Qi-Wei Lu , Zhong-Xiang Wang , Yi Xing

We present first results from a LOFAR census of non-recycled pulsars. The census includes almost all such pulsars known (194 sources) at declinations ${\rm Dec}> 8^\circ$ and Galactic latitudes $|{\rm Gb}| > 3^\circ$, regardless of their…

We discuss the possibilities of measuring ultra-high energy cosmic rays and neutrinos with radio techniques. We review a few of the properties of radio emission from cosmic ray air showers and show how these properties can be explained by…

Astrophysics · Physics 2011-04-20 Heino Falcke , Peter Gorham

In this Letter, we report the discovery of a radio halo in the high-redshift galaxy cluster PSZ2 G099.86+58.45 ($z=0.616$) with the LOw Frequency ARray (LOFAR) at 120-168 MHz. This is one of the most distant radio halos discovered so far.…

High-precision timing of millisecond pulsars (MSPs) over years to decades is a promising technique for direct detection of gravitational waves at nanohertz frequencies. Time-variable, multi-path scattering in the interstellar medium is a…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Anne M. Archibald , Vladislav I. Kondratiev , Jason W. T. Hessels , Daniel R. Stinebring

Phased Array Feed (PAF) receivers are at the forefront of modern day radio astronomy. PAFs are currently being developed for spectral line and radio continuum surveys and to search for pulsars and fast radio bursts. Here, we present results…

High Energy Astrophysical Phenomena · Physics 2019-08-21 K. M. Rajwade , D. Agarwal , D. R. Lorimer , N. M. Pingel , D. J. Pisano , M. Ruzindana , B. Jeffs , K. F. Warnick , D. A. Roshi , M. A. McLaughlin

We show that it is possible to locate the few places on the body of an airplane, while it is flying through high clouds, from which broad-band, pulsed, radiation is emitted at Very High Frequency (VHF) radio frequencies. This serendipitous…

Transient radio phenomena and pulsars are one of six LOFAR Key Science Projects (KSPs). As part of the Transients KSP, the Pulsar Working Group (PWG) has been developing the LOFAR Pulsar Data Pipelines to both study known pulsars as well as…

Instrumentation and Methods for Astrophysics · Physics 2015-03-17 A. Alexov , J. W. T. Hessels , J. D. Mol , B. Stappers , J. van Leeuwen

FRB 20180916B is a well-studied repeating fast radio burst source. Its proximity (~150 Mpc), along with detailed studies of the bursts, have revealed many clues about its nature -- including a 16.3-day periodicity in its activity. Here we…

Recent work has made it clear that the ``standard model'' of pulsar radio emission cannot be the full answer. Some fundamental assumptions about the magnetic field and plasma flow in the radio-loud region have been called into question by…

Astrophysics · Physics 2007-05-23 J. A. Eilek , T. H. Hankins , A. Jessner

Recent Low Frequency Array (LOFAR) observations at 115-175 MHz of a field at medium Galactic latitudes (centered at the bright quasar 3C196) have shown striking filamentary structures in polarization that extend over more than 4 degrees…

The LOFAR Two-metre Sky Survey (LoTSS) is an ongoing sensitive, high-resolution 120-168MHz survey of the entire northern sky for which observations are now 20% complete. We present our first full-quality public data release. For this data…

Astrophysics of Galaxies · Physics 2018-11-21 T. W. Shimwell , C. Tasse , M. J. Hardcastle , A. P. Mechev , W. L. Williams , P. N. Best , H. J. A. Röttgering , J. R. Callingham , T. J. Dijkema , F. de Gasperin , D. N. Hoang , B. Hugo , M. Mirmont , J. B. R. Oonk , I. Prandoni , D. Rafferty , J. Sabater , O. Smirnov , R. J. van Weeren , G. J. White , M. Atemkeng , L. Bester , E. Bonnassieux , M. Brüggen , G. Brunetti , K. T. Chyży , R. Cochrane , J. E. Conway , J. H. Croston , A. Danezi , K. Duncan , M. Haverkorn , G. H. Heald , M. Iacobelli , H. T. Intema , N. Jackson , M. Jamrozy , M. J. Jarvis , R. Lakhoo , M. Mevius , G. K. Miley , L. Morabito , R. Morganti , D. Nisbet , E. Orrú , S. Perkins , R. F. Pizzo , C. Schrijvers , D. J. B. Smith , R. Vermeulen , M. W. Wise , L. Alegre , D. J. Bacon , I. M. van Bemmel , R. J. Beswick , A. Bonafede , A. Botteon , S. Bourke , M. Brienza , G. Calistro Rivera , R. Cassano , A. O. Clarke , C. J. Conselice , R. J. Dettmar , A. Drabent , C. Dumba , K. L. Emig , T. A. Enßlin , C. Ferrari , M. A. Garrett , R. T. Génova-Santos , A. Goyal , G. Gürkan , C. Hale , J. J. Harwood , V. Heesen , M. Hoeft , C. Horellou , C. Jackson , G. Kokotanekov , R. Kondapally , M. Kunert-Bajraszewska , V. Mahatma , E. K. Mahony , S. Mandal , J. P. McKean , A. Merloni , B. Mingo , A. Miskolczi , S. Mooney , B. Nikiel-Wroczyński , S. P. O'Sullivan , J. Quinn , W. Reich , C. Roskowiński , A. Rowlinson , F. Savini , A. Saxena , D. J. Schwarz , A. Shulevski , S. S. Sridhar , H. R. Stacey , S. Urquhart , M. H. D. van der Wiel , E. Varenius , B. Webster , A. Wilber

The presence of large-scale magnetic fields and ultra-relativistic electrons in the intra-cluster medium (ICM) is confirmed through the detection of diffuse radio synchrotron sources, so-called radio halos and relics. Due to their…

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,…

Enhanced inverse Compton (IC) losses at high redshift steepen diffuse radio spectra in galaxy clusters, making low-frequency (~100 MHz) observations favorable. However, low-frequency studies often lack the resolution needed to locate…

The energy reconstruction of extensive air showers measured with the LOFAR Radboud Air Shower Array (LORA) is presented in detail. LORA is a particle detector array located in the center of the LOFAR radio telescope in the Netherlands. The…

The behaviour of fast radio bursts (FRBs) at radio frequencies <400 MHz is not well understood due to very few detections, with only two known sources detected below 300 MHz. Characterising low-frequency emission of FRBs is vital for…

High Energy Astrophysical Phenomena · Physics 2025-12-03 Pragya Chawla , Akshatha Gopinath , Ninisha Manaswini , Cees Bassa , Jason Hessels , Vlad Kondratiev , Daniele Michilli , Ziggy Pleunis

The LOw-Frequency ARray is a low-frequency radio interferometer composed by observational stations spread across Europe and it is the largest precursor of SKA in terms of effective area and generated data rates. In 2018, the Italian…