A calibration strategy using full-Jones corrections with an in-field unpolarised calibrator and visibility-based multi-epoch alignment enables sub-arcsecond polarimetric imaging with LOFAR at metre wavelengths.
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The LOFAR Two-metre Sky Survey - II. First data release
10 Pith papers cite this work. Polarity classification is still indexing.
10
Pith papers citing it
abstract
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 release 424 square degrees, or 2% of the eventual coverage, in the region of the HETDEX Spring Field (right ascension 10h45m00s to 15h30m00s and declination 45$^\circ$00$'$00$''$ to 57$^\circ$00$'$00$''$) were mapped using a fully automated direction-dependent calibration and imaging pipeline that we developed. A total of 325,694 sources are detected with a signal of at least five times the noise, and the source density is a factor of $\sim 10$ higher than the most sensitive existing very wide-area radio-continuum surveys. The median sensitivity is S$_{\rm 144 MHz} = 71\,\mu$Jy beam$^{-1}$ and the point-source completeness is 90% at an integrated flux density of 0.45mJy. The resolution of the images is 6$''$ and the positional accuracy is within 0.2$''$. This data release consists of a catalogue containing location, flux, and shape estimates together with 58 mosaic images that cover the catalogued area. In this paper we provide an overview of the data release with a focus on the processing of the LOFAR data and the characteristics of the resulting images. In two accompanying papers we provide the radio source associations and deblending and, where possible, the optical identifications of the radio sources together with the photometric redshifts and properties of the host galaxies. These data release papers are published together with a further $\sim$20 articles that highlight the scientific potential of LoTSS.
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representative citing papers
AGN radiation pressure, not black-hole mass, simultaneously boosts large-scale [O III] outflows and clears circumnuclear gas as Eddington ratio rises.
Probabilistic spectroscopic classification of 251k LoTSS radio sources yields the largest high-confidence sample and confirms LERGs accrete below ~1% Eddington while HERGs accrete above it.
UVIT FUV catalogues of ELAIS N1 plus CIGALE SED fits show SFR increasing with redshift and a flat young-to-total stellar mass ratio to z≲0.76, consistent with secular SFMS evolution.
Presents ultra-low frequency spectral index maps for 22 bright extended radio galaxies showing indices of ~0.5 near cores rising to >1.0 in lobes for FR I sources and 0.5-0.9 in FR II hotspots.
New ASKAP continuum imaging classifies jet morphologies in 173 G4Jy-3CRE sources (66% of sample) including 37 newly detected jets and identifies six new optical counterparts.
Empirical scalability model for LOFAR DI pipeline runtime based on tests varying CPUs, data size, and sky model size, with validation on production runs.
The chapter summarizes gaps in AGN jet research and projects how SKA standalone and combined observations will address jet-host galaxy co-evolution across scales.
Optical spectroscopy is required to unlock the full potential of SKAO extragalactic surveys through precise redshifts, activity diagnostics, HI stacking, and large-scale structure mapping.
This review chapter summarizes the cosmic web's theoretical framework, recent radio observations of diffuse gas, and the expected impact of the SKA on detecting baryons in filaments and cluster outskirts.
citing papers explorer
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Polarisation and Faraday rotation measure imaging at metre wavelengths with sub-arcsecond resolution: a foundational calibration strategy
A calibration strategy using full-Jones corrections with an in-field unpolarised calibrator and visibility-based multi-epoch alignment enables sub-arcsecond polarimetric imaging with LOFAR at metre wavelengths.
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AGN radiative feedback as the main regulator of [O III] outflow activity and obscuration in X-ray AGN
AGN radiation pressure, not black-hole mass, simultaneously boosts large-scale [O III] outflows and clears circumnuclear gas as Eddington ratio rises.
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The DESI View of the Faint Radio Source Population in LoTSS DR2
Probabilistic spectroscopic classification of 251k LoTSS radio sources yields the largest high-confidence sample and confirms LERGs accrete below ~1% Eddington while HERGs accrete above it.
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Deep far-UV observations of the ELAIS N1 field using AstroSat: Source catalogue, spectral energy distribution modelling and star formation
UVIT FUV catalogues of ELAIS N1 plus CIGALE SED fits show SFR increasing with redshift and a flat young-to-total stellar mass ratio to z≲0.76, consistent with secular SFMS evolution.
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The ultra low-frequency spectral properties of bright extended radio galaxies in the 3CRR catalogue
Presents ultra-low frequency spectral index maps for 22 bright extended radio galaxies showing indices of ~0.5 near cores rising to >1.0 in lobes for FR I sources and 0.5-0.9 in FR II hotspots.
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Powerful Radio Sources in the Southern Sky. IV. Observations of the G4Jy-3CRE Catalog with the Australian Square Kilometre Array Pathfinder
New ASKAP continuum imaging classifies jet morphologies in 173 G4Jy-3CRE sources (66% of sample) including 37 newly detected jets and identifies six new optical counterparts.
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Scalability Model for the LOFAR Direction Independent Pipeline
Empirical scalability model for LOFAR DI pipeline runtime based on tests varying CPUs, data size, and sky model size, with validation on production runs.
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AGN Jets from Formation to Dissipation
The chapter summarizes gaps in AGN jet research and projects how SKA standalone and combined observations will address jet-host galaxy co-evolution across scales.
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Unlocking the Full Potential of SKAO Extra-galactic Science with High-multiplex Optical Spectroscopy
Optical spectroscopy is required to unlock the full potential of SKAO extragalactic surveys through precise redshifts, activity diagnostics, HI stacking, and large-scale structure mapping.
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The Large-Scale Structure of the Universe through the SKA lenses
This review chapter summarizes the cosmic web's theoretical framework, recent radio observations of diffuse gas, and the expected impact of the SKA on detecting baryons in filaments and cluster outskirts.