Strong detection of the CMB lensing and galaxy weak lensing cross-correlation from ACT-DR4, Planck Legacy, and KiDS-1000

Naomi Clare Robertson, David Alonso, Joachim Harnois-Déraps, Omar Darwish, Arun Kannawadi, Alexandra Amon, Marika Asgari, MacIej Bilicki, Erminia Calabrese, Steve K. Choi, Mark J. Devlin, Jo Dunkley, Andrej Dvornik, Thomas Erben, Simone Ferraro, Maria Cristina Fortuna, Benjamin Giblin, Dongwon Han, Catherine Heymans, Hendrik HildebrandtJ. Colin Hill, Matt Hilton, Shuay Pwu P. Ho, Henk Hoekstra, Johannes Hubmayr, John P. Hughes, Benjamin Joachimi, Shahab Joudaki, Kenda Knowles, Konrad Kuijken, Mathew S. Madhavacheril, Kavilan Moodley, Lance Miller, Toshiya Namikawa, Federico Nati, Michael D. Niemack, Lyman A. Page, Bruce Partridge, Emmanuel Schaan, Alessandro Schillaci, Peter Schneider, Neelima Sehgal, Blake D. Sherwin, Cristóbal Sifón, Suzanne T. Staggs, Tilman Tröster, Alexander Van Engelen, Edwin Valentijn, Edward J. Wollack, Angus H. Wright, Zhilei Xu

Research output: Contribution to journalArticlepeer-review

27 Scopus citations


We measured the cross-correlation between galaxy weak lensing data from the Kilo Degree Survey (KiDS-1000, DR4) and cosmic microwave background (CMB) lensing data from the Atacama Cosmology Telescope (ACT, DR4) and the Planck Legacy survey. We used two samples of source galaxies, selected with photometric redshifts, (0.1 < zB < 1.2) and (1.2 < zB < 2), which produce a combined detection significance of the CMB lensing and weak galaxy lensing cross-spectrum of 7.7σ. With the lower redshift galaxy sample, for which the cross-correlation was detected at a significance of 5.3σ, we present joint cosmological constraints on the matter density parameter, ωm, and the matter fluctuation amplitude parameter, σ8, marginalising over three nuisance parameters that model our uncertainty in the redshift and shear calibration as well as the intrinsic alignment of galaxies. We find our measurement to be consistent with the best-fitting flat ΛCDM cosmological models from both Planck and KiDS-1000. We demonstrate the capacity of CMB weak lensing cross-correlations to set constraints on either the redshift or shear calibration by analysing a previously unused high-redshift KiDS galaxy sample (1.2 < zB < 2), with the cross-correlation detected at a significance of 7σ. This analysis provides an independent assessment for the accuracy of redshift measurements in a regime that is challenging to calibrate directly owing to known incompleteness in spectroscopic surveys.

Original languageEnglish (US)
Article numberA146
JournalAstronomy and Astrophysics
StatePublished - May 1 2021

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • Cosmology: observations
  • Gravitational lensing: weak
  • Large-scale structure of Universe


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