163 citations · 3.2k across the 56 of their papers we have counts for
15 papers · 1 filter
Combining LOFAR and Apertif Data for Understanding the Life Cycle of Radio Galaxies
Raffaella Morganti, Nika Jurlin, Tom Oosterloo +10
Active galactic nuclei (AGN) at the centres of galaxies can cycle between periods of activity and of quiescence. Characterising the duty-cycle of AGN is crucial for understanding t…
Sub-arcsecond imaging with the International LOFAR Telescope: II. Completion of the LOFAR Long-Baseline Calibrator Survey
Neal Jackson, Shruti Badole, John Morgan +69
The Low-Frequency Array (LOFAR) Long-Baseline Calibrator Survey (LBCS) was conducted between 2014 and 2019 in order to obtain a set of suitable calibrators for the LOFAR array. In…
LOFAR imaging of Cygnus A -- Direct detection of a turnover in the hotspot radio spectra
J. P. McKean, L. E. H. Godfrey, S. Vegetti +75
The low-frequency radio spectra of the hotspots within powerful radio galaxies can provide valuable information about the physical processes operating at the site of the jet termin…
Extreme intra-hour variability of the radio source J1402+5347 discovered with Apertif
T. A. Oosterloo, H. K. Vedantham, A. M. Kutkin +27
The propagation of radio waves from distant compact radio sources through turbulent interstellar plasma in our Galaxy causes these sources to twinkle, a phenomenon called interstel…
Low-frequency observations of the Giant Radio Galaxy NGC 6251
T. M. Cantwell, J. D. Bray, J. H. Croston +22
We present LOFAR observations at 150 MHz of the borderline FRI/FRII giant radio galaxy NGC 6251. This paper presents the most sensitive and highest-resolution images of NGC 6251 at…
A radio ridge connecting two galaxy clusters in a filament of the cosmic web
F. Govoni, E. Orrù, A. Bonafede +26
Galaxy clusters are the most massive gravitationally bound structures in the Universe. They grow by accreting smaller structures in a merging process that produces shocks and turbu…
LOFAR MSSS: Flattening low-frequency radio continuum spectra of nearby galaxies
K. T. Chyży, W. Jurusik, J. Piotrowska +35
The shape of low-frequency radio continuum spectra of normal galaxies is not well understood, the key question being the role of physical processes such as thermal absorption in sh…
LOFAR MSSS: Discovery of a 2.56 Mpc giant radio galaxy associated with a disturbed galaxy group
A. O. Clarke, G. Heald, T. Jarrett +40
We report on the discovery in the LOFAR Multifrequency Snapshot Sky Survey (MSSS) of a giant radio galaxy (GRG) with a projected size of Mpc projected on the sky. I…
FR II radio galaxies at low frequencies I: morphology, magnetic field strength and energetics
Jeremy J. Harwood, Judith H. Croston, Huib T. Intema +14
Due to their steep spectra, low-frequency observations of FR II radio galaxies potentially provide key insights in to the morphology, energetics and spectrum of these powerful radi…
LOFAR low-band antenna observations of the 3C295 and Bootes fields: source counts and ultra-steep spectrum sources
R. J. van Weeren, W. L. Williams, C. Tasse +98
We present LOFAR Low Band observations of the Bootes and 3C295 fields. Our images made at 34, 46, and 62 MHz reach noise levels of 12, 8, and 5 mJy beam, making them the dee…
Filaments in the southern giant lobe of Centaurus A: constraints on nature and origin from modelling and GMRT observations
Sarka Wykes, Huib T. Intema, Martin J. Hardcastle +8
We present results from imaging of the radio filaments in the southern giant lobe of Centaurus A using data from GMRT observations at 325 and 235 MHz, and outcomes from filament mo…
The spectral structure and energetics of powerful radio sources
J. J. Harwood, M. J. Hardcastle, J. H. Croston +3
Determining the energy spectrum of an electron population can give key insights into the underlying physics of a radio source; however, the lack of high resolution, broad-bandwidth…
Discovery of Carbon Radio Recombination Lines in absorption towards Cygnus~A
J. B. R. Oonk, R. J. van Weeren, F. Salgado +100
We present the first detection of carbon radio recombination line absorption along the line of sight to Cygnus A. The observations were carried out with the LOw Frequency ARray in…
Studying Galactic interstellar turbulence through fluctuations in synchrotron emission: First LOFAR Galactic foreground detection
M. Iacobelli, M. Haverkorn, E. Orrú +85
The characteristic outer scale of turbulence and the ratio of the random to ordered components of the magnetic field are key parameters to characterise magnetic turbulence in the i…
LOFAR detections of low-frequency radio recombination lines towards Cassiopeia A
Ashish Asgekar, J. B. R. Oonk, S. Yatawatta +89
Cassiopeia A was observed using the Low-Band Antennas of the LOw Frequency ARray (LOFAR) with high spectral resolution. This allowed a search for radio recombination lines (RRLs) a…