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Title: Cosmology from LOFAR Two-metre Sky Survey Data Release 2: Cross-correlation with the cosmic microwave background
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,Cgk, as well as its auto-correlation,Cgg. We explored the models describing the redshift evolution of the large-scale radio galaxy bias, discriminating between them through the combination of bothCgkandCgg. 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 theCgksignal 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 forCgg, andℓ< 500 forCgk. 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.  more » « less
Award ID(s):
2108402
PAR ID:
10524202
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ;
Publisher / Repository:
EDP Sciences
Date Published:
Journal Name:
Astronomy & Astrophysics
Volume:
681
ISSN:
0004-6361
Page Range / eLocation ID:
A105
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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