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Exploring the radio-loudness of SDSS quasars with spectral stacking
(2024-01-22)
We use new 144 MHz observations over 5634 deg 2 from the LOFAR (Low Frequency Array) Two-metre Sky Survey (LoTSS) to compile the largest sample of uniformly selected, spectroscopically confirmed quasars from the 14th data ...
Possible discovery of Calvera's supernova remnant
(2022-11-01)
We report the discovery of a ring of low surface brightness radio emission around the Calvera pulsar, a high Galactic latitude, isolated neutron star, in the LOFAR Two-metre Sky Survey (LoTSS). It is centered at α = ...
Sub-arcsecond imaging with the International LOFAR Telescope : I. Foundational calibration strategy and pipeline
(2022-02-28)
The International LOFAR Telescope is an interferometer with stations spread across Europe. With baselines of up to ∼2000 km, LOFAR has the unique capability of achieving sub-arcsecond resolution at frequencies below 200 ...
The LOFAR Two-metre Sky Survey -- V. Second data release
(2022-02-25)
In this data release from the ongoing LOw-Frequency ARray (LOFAR) Two-metre Sky Survey we present 120a 168 MHz images covering 27% of the northern sky. Our coverage is split into two regions centred at approximately 12h45m ...
The population of M dwarfs observed at low radio frequencies
(2021-10-11)
Coherent low-frequency (≲200 MHz) radio emission from stars encodes the conditions of the outer corona, mass-ejection events and space weather 1–5. Previous low-frequency searches for radio-emitting stellar systems have ...
The LOFAR Two-metre Sky Survey Deep fields: : The star formation rate - radio luminosity relation at low frequencies
(2021-04-07)
In this paper, we investigate the relationship between 150 MHz luminosity and the star-formation rate - the SFR-L150 MHz relation - using 150 MHz measurements for a near-infrared selected sample of 118 517 z < 1 galaxies. ...
Coherent radio emission from a quiescent red dwarf indicative of star-planet interaction
(2020-02-17)
Low-frequency (ν ≲ 150 MHz) stellar radio emission is expected to originate in the outer corona at heights comparable to and larger than the stellar radius. Such emission from the Sun has been used to study coronal structure, ...
Revived Fossil Plasma Sources in Galaxy Clusters
(2020-01-28)
It is well established that particle acceleration by shocks and turbulence in the intra-cluster medium can produce cluster-scale synchrotron emitting sources. However, the detailed physics of these particle acceleration ...
Untangling cosmic magnetic fields: Faraday tomography at metre wavelengths with LOFAR
(2018-11-29)
The technique of Faraday tomography is a key tool for the study ofmagnetised plasmas in the new era of broadband radio-polarisation observations. In particular, observations at metre wavelengths provide significantly better ...
Remnant radio-loud AGN in the Herschel-ATLAS field
(2018-04-21)
Only a small fraction of observed active galactic nuclei (AGN) display large-scale radio emission associated with jets, yet these radio-loud AGN have become increasingly important in models of galaxy evolution. In determining ...