Cosmology from LOFAR Two-metre Sky Survey Data Release 2: Cross-correlation with the cosmic microwave background

Astronomy and Astrophysics, vol. 681, pp. A105

Abstract

Aims. We combined the LOw-Frequency ARray (LOFAR) Two-metre Sky Survey (LoTSS) second data release (DR2) catalogue with gravitational lensing maps from the cosmic microwave background (CMB) to place constraints on the bias evolution of LoTSS-detected radio galaxies, and on the amplitude of matter perturbations. Methods. We constructed a flux-limited catalogue from LoTSS DR2, and analysed its harmonic-space cross-correlation with CMB lensing maps fromPlanck,Cℓgk, as well as its auto-correlation,Cℓgg. We explored the models describing the redshift evolution of the large-scale radio galaxy bias, discriminating between them through the combination of bothCℓgkandCℓgg. Fixing the bias evolution, we then used these data to place constraints on the amplitude of large-scale density fluctuations, parametrised byσ8. Results. We report the significance of theCℓgksignal at a level of 26.6σ. We determined that a linear bias evolution of the formbg(z) =bg,D/D(z), whereD(z) is the growth rate, is able to provide a good description of the data, and we measuredbg,D= 1.41 ± 0.06 for a sample that is flux limited at 1.5 mJy, for scalesℓ< 250 forCℓgg, andℓ< 500 forCℓgk. At the sample’s median redshift, we obtainedb(z= 0.82) = 2.34 ± 0.10. Usingσ8as a free parameter, while keeping other cosmological parameters fixed to thePlanckvalues, we found fluctuations of σ8= 0.75−0.04+0.05. The result is in agreement with weak lensing surveys, and at 1σdifference withPlanckCMB constraints. We also attempted to detect the late-time-integrated Sachs-Wolfe effect with LOFAR data; however, with the current sky coverage, the cross-correlation with CMB temperature maps is consistent with zero. Our results are an important step towards constraining cosmology with radio continuum surveys from LOFAR and other future large radio surveys.

Authors 12

1. Szymon J. Nakoneczny

   California Institute of Technology · National Centre for Nuclear Research

   Affiliation as printed

   Department of Astrophysics, National Centre for Nuclear Research, Pasteura 7, 02-093 Warsaw, Poland

   Division of Physics, Mathematics and Astronomy, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USA

   Division of Physics, Mathematics and Astronomy, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125

2. David Alonso

   University of Oxford

   Affiliation as printed

   Sub-department of Astrophysics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 2DL, UK

3. Maciej Bilicki

   Center for Theoretical Physics · Polish Academy of Sciences

   Affiliation as printed

   Center for Theoretical Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland

4. Dominik J. Schwarz

   Bielefeld University

   Affiliation as printed

   Fakultät für Physik, Universität Bielefeld, Postfach 100131, 33501 Bielefeld, Germany

5. Catherine Laura Hale

   Royal Observatory · University of Edinburgh

   Affiliation as printed

   Institute for Astronomy, School of Physics and Astronomy, University of Edinburgh, Royal Observatory Edinburgh, Blackford Hill, Edinburgh, EH9 3HJ, UK

6. A. Pollo

   Jagiellonian University · National Centre for Nuclear Research

   Affiliation as printed

   Astronomical Observatory of the Jagiellonian University, 31-007 Cracow, Poland

   Department of Astrophysics, National Centre for Nuclear Research, Pasteura 7, 02-093 Warsaw, Poland

7. Caroline S. Heneka

   Heidelberg University

   Affiliation as printed

   Institute for Theoretical Physics, Heidelberg University, Philosophenweg 16, 69120 Heidelberg, Germany

8. Prabhakar Tiwari

   Chinese Academy of Sciences · Guangdong Technion-Israel Institute of Technology · National Astronomical Observatories

   Affiliation as printed

   National Astronomical Observatories, Chinese Academy of Science, Beijing, 100101, PR China

   Department of Physics, Guangdong Technion -Israel Institute of Technology, Shantou, Guangdong 515063, P.R. China

9. J. Q. Zheng

   Bielefeld University

   Affiliation as printed

   Fakultät für Physik, Universität Bielefeld, Postfach 100131, 33501 Bielefeld, Germany

10. M. Brüggen

    Universität Hamburg

    Affiliation as printed

    Hamburg Observatory, University of Hamburg, Gojenbersgweg 112, 21029 Hamburg, Germany

11. M. J. Jarvis

    University of Oxford · University of the Western Cape

    Affiliation as printed

    Department of Physics, University of the Western Cape, Bellville 7535, South Africa

    Sub-department of Astrophysics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 2DL, UK

12. T. W. Shimwell Aachen Leiden Observatory

    Leiden University · Leiden Observatory · Netherlands Institute for Radio Astronomy

    Affiliation as printed

    ASTRON, Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD, Dwingeloo, The Netherlands

    Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands

    Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden, The Netherlands