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Record W4205847426 · doi:10.1051/0004-6361/202142484

The LOFAR Two-metre Sky Survey

2022· article· en· W4205847426 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.
fundA Canadian funder is recorded on the work.

Bibliographic record

VenueAstronomy and Astrophysics · 2022
Typearticle
Languageen
FieldPhysics and Astronomy
TopicRadio Astronomy Observations and Technology
Canadian institutionsCanadian Institute for Theoretical AstrophysicsUniversity of Toronto
FundersFP7 International CooperationDST-NRF Centre Of Excellence In Tree Health BiotechnologyGauss Centre for SupercomputingNarodowa Agencja Wymiany AkademickiejMinisterium für Innovation, Wissenschaft und Forschung des Landes Nordrhein-WestfalenMinistero degli Affari Esteri e della Cooperazione InternazionaleNatural Sciences and Engineering Research Council of CanadaDepartment of Science and Innovation, South AfricaIstituto Nazionale di AstrofisicaCentre National de la Recherche ScientifiqueChina Scholarship CouncilMax-Planck-GesellschaftBundesministerium für Bildung und ForschungUniversity of the Western CapeNederlandse Organisatie voor Wetenschappelijk OnderzoekScience and Technology Facilities CouncilHorizon 2020 Framework ProgrammeHrvatska Zaklada za ZnanostNarodowym Centrum NaukiCanada Research ChairsUK Research and InnovationScience Foundation IrelandObservatoire de Paris, Université de Recherche Paris Sciences et LettresNational Research FoundationUniversity of PretoriaAlexander von Humboldt-StiftungUniversity of HertfordshireEuropean CommissionDipartimenti di EccellenzaDeutsche ForschungsgemeinschaftUniversity of TorontoMinistero dell’Istruzione, dell’Università e della RicercaUniversity of Cape TownUniversité d'OrléansLeverhulme Trust
KeywordsLOFARPhysicsSpectral indexSkyOpticsSky brightnessBrightnessRemote sensingWavelengthAstrophysicsRadio telescopeAstronomyGeologySpectral line

Abstract

fetched live from OpenAlex

In this data release from the ongoing LOw-Frequency ARray (LOFAR) Two-metre Sky Survey we present 120–168 MHz images covering 27% of the northern sky. Our coverage is split into two regions centred at approximately 12h45m +44°30′ and 1h00m +28°00′ and spanning 4178 and 1457 square degrees respectively. The images were derived from 3451 h (7.6 PB) of LOFAR High Band Antenna data which were corrected for the direction-independent instrumental properties as well as direction-dependent ionospheric distortions during extensive, but fully automated, data processing. A catalogue of 4 396 228 radio sources is derived from our total intensity (Stokes I ) maps, where the majority of these have never been detected at radio wavelengths before. At 6″ resolution, our full bandwidth Stokes I continuum maps with a central frequency of 144 MHz have: a median rms sensitivity of 83 μJy beam −1 ; a flux density scale accuracy of approximately 10%; an astrometric accuracy of 0.2″; and we estimate the point-source completeness to be 90% at a peak brightness of 0.8 mJy beam −1 . By creating three 16 MHz bandwidth images across the band we are able to measure the in-band spectral index of many sources, albeit with an error on the derived spectral index of > ± 0.2 which is a consequence of our flux-density scale accuracy and small fractional bandwidth. Our circular polarisation (Stokes V ) 20″ resolution 120–168 MHz continuum images have a median rms sensitivity of 95 μJy beam −1 , and we estimate a Stokes I to Stokes V leakage of 0.056%. Our linear polarisation (Stokes Q and Stokes U ) image cubes consist of 480 × 97.6 kHz wide planes and have a median rms sensitivity per plane of 10.8 mJy beam −1 at 4′ and 2.2 mJy beam −1 at 20″; we estimate the Stokes I to Stokes Q / U leakage to be approximately 0.2%. Here we characterise and publicly release our Stokes I , Q , U and V images in addition to the calibrated uv -data to facilitate the thorough scientific exploitation of this unique dataset.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesScience and technology studies
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Not applicable · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.864
Threshold uncertainty score0.999

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0020.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.009
GPT teacher head0.213
Teacher spread0.204 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it