One- and Two-point Source Statistics from the LOFAR Two-metre Sky Survey First Data Release

Abstract

The LOFAR Two-metre Sky Survey (LoTSS) will map the complete Northern sky and provide an excellent opportunity to study the distribution and evolution of the large-scale structure of the Universe. We study the completeness of the LoTSS first data release (DR1) and find a point-source completeness of 99 % above flux densities of 0.8 mJy and define a suite of quality cuts. We determine the count-in-cell statistics and differential source counts statistic and measure the angular two-point correlation function of the LoTSS radio sources. The counts-in-cell statistic reveals that the distribution of radio sources cannot be described by a spatial Poisson process. Instead, a good fit is provided by a compound Poisson distribution. The differential source counts are in good agreement with previous findings in deep fields at low radio frequencies and with simulated catalogues from the SKA design study sky and the Tiered Radio Extragalactic Continuum Simulation. The angular two-point correlation is $<10^{-2}$ at angular scales $>1$ deg. Restricting the value added source catalogue to low-noise regions and a flux density threshold of 2 mJy provides our most reliable estimate of the angular two-point correlation. For smaller flux density thresholds systematic issues are identified, most likely related to the flux density calibration of the individual pointings. Based on the distribution of photometric redshifts of LoTSS sources and the Planck 2018 best-fit cosmological model, the theoretically predicted angular two-point correlation between 0.1 deg and 6 deg agrees with the measured clustering for a subsample of radio sources with redshift information. We find agreement with the expectation of large-scale statistical isotropy of the radio sky at the per cent level. The angular two-point correlation agrees well with the expectation of the cosmological standard model. (abbreviated)

30 pages, 35 figures; corrections of affiliations and acknowledgements; version accepted by A&A

References in corpus (66)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Astropy: A Community Python Package for Astronomy
• The NumPy array: a structure for efficient numerical computation
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• Large scale bias and the peak background split
• LOFAR: The LOw-Frequency ARray
• Exploring the Expansion History of the Universe
• Accelerating Universes with Scaling Dark Matter
• Planck 2018 results. I. Overview and the cosmological legacy of Planck
• An analytic model for the spatial clustering of dark matter haloes
• Revising the Halofit Model for the Nonlinear Matter Power Spectrum
• The Halo Occupation Distribution: Towards an Empirical Determination of the Relation Between Galaxies and Mass
• Theoretical Models of the Halo Occupation Distribution: Separating Central and Satellite Galaxies
• The GMRT 150 MHz All-sky Radio Survey: First Alternative Data Release TGSS ADR1
• The imprints of primordial non-gaussianities on large-scale structure: scale dependent bias and abundance of virialized objects
• The LOFAR Two-metre Sky Survey - I. Survey Description and Preliminary Data Release
• Constraining Galaxy Formation and Cosmology with the Conditional Luminosity Function of Galaxies
• The LOFAR Two-metre Sky Survey - II. First data release
• GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey I: A low-frequency extragalactic catalogue
• The linear power spectrum of observed source number counts
• Planck 2018 results. VII. Isotropy and Statistics of the CMB
• Planck 2015 results. XVI. Isotropy and statistics of the CMB
• An accurate halo model for fitting non-linear cosmological power spectra and baryonic feedback models
• Measuring the dark side (with weak lensing)
• The effect of primordial non-Gaussianity on halo bias
• The Skewness of the Aperture Mass Statistic
• On Departures From a Power Law in the Galaxy Correlation Function
• Cosmology with Phase 1 of the Square Kilometre Array; Red Book 2018: Technical specifications and performance forecasts
• LOFAR 150-MHz observations of the Boötes field: Catalogue and Source Counts
• A comparison of estimators for the two-point correlation function
• The LoTSS view of radio AGN in the local Universe. The most massive galaxies are always switched on
• Cosmic radio dipole from NVSS and WENSS
• Radio-loud AGN in the first LoTSS data release: The lifetimes and environmental impact of jet-driven sources
• The LOFAR Two-metre Sky Survey (LoTSS) III. First Data Release: optical/IR identifications and value-added catalogue
• Probing modifications of General Relativity using current cosmological observations
• The Tiered Radio Extragalactic Continuum Simulation (T-RECS)
• Probing the Cosmological Principle in the counts of radio galaxies at different frequencies
• A radio spectral index map and catalogue at 147-1400 MHz covering 80 per cent of the sky
• Revisiting the NVSS number count dipole
• The Angular Two-Point Correlation Function for the FIRST Radio Survey
• Variance and Skewness in the FIRST survey
• The Lockman Hole project: LOFAR observations and spectral index properties of low-frequency radio sources
• Radio Galaxy populations and the multi-tracer technique: pushing the limits on primordial non-Gaussianity
• The LOFAR Two-metre Sky Survey IV. First Data Release: Photometric redshifts and rest-frame magnitudes
• Quantifying angular clustering in wide-area radio surveys
• Comparing estimators of the galaxy correlation function
• Cosmological Measurements with Forthcoming Radio Continuum Surveys
• The 154 MHz radio sky observed by the Murchison Widefield Array: noise, confusion and first source count analyses
• Sample variance, source clustering and their influence on the counts of faint radio sources
• The clustering and bias of radio-selected AGN and star-forming galaxies in the COSMOS field
• The clustering properties of radio-selected AGN and star-forming galaxies up to redshifts z~3
• Probing primordial non-Gaussianity via iSW measurements with SKA continuum surveys
• The galaxy-halo connection in the VIDEO Survey at 0.5<z<1.7
• The clustering of radio galaxies: biasing and evolution versus stellar mass
• An optimized correlation function estimator for galaxy surveys
• Testing the standard model of cosmology with the SKA: the cosmic radio dipole
• The best fit for the observed galaxy Counts-in-Cell distribution function
• Angular clustering in the SUMSS radio survey
• Impact of Redshift Information on Cosmological Applications with Next-Generation Radio Surveys
• TWO-POINT ANGULAR CORRELATION FUNCTION FOR THE GREEN BANK 4.85 GHZ SKY SURVEY
• Environmental Quenching and Galactic Conformity in the Galaxy Cross-Correlation Signal
• The clustering of sub-mJy radio sources in The Bootes Deep Field
• Angular clustering of point sources at 150 MHz in the TGSS survey
• Measuring ISW with next-generation radio surveys
• Clustering properties of TGSS radio sources

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• A measurement of the Integrated Sachs-Wolfe Effect with the Rapid ASKAP Continuum Survey
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• The Evolutionary Map of the Universe Pilot Survey
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• The Angular Correlation Function as measured by the GLEAM-X Survey
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