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KiDS-Legacy: The consistency test of the large-scale structure with Bernardeau-Nishimichi-Taruya transform
Authors:
Shiming Gu,
Ziang Yan,
Ludovic van Waerbeke,
Francis Bernardeau,
Hendrik Hildebrandt,
Angus H. Wright,
Maciej Bilicki,
Christos Georgiou,
Shun-Sheng Li,
Laila Linke,
Lauro Moscardini,
Robert Reischke,
Benjamin Stölzner
Abstract:
We perform the first $k$-cut cosmic shear analysis of the KiDS-Legacy survey. This method uses the Bernardeau-Nishimichi-Taruya (BNT) transform to construct weak-lensing kernels that are more localised than conventional ones, and remove information from selected physical scales while retaining the constraining power of the targeted range. Removing the scale of $k \geq 0.33~\mathrm{Mpc}^{-1}$ from…
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We perform the first $k$-cut cosmic shear analysis of the KiDS-Legacy survey. This method uses the Bernardeau-Nishimichi-Taruya (BNT) transform to construct weak-lensing kernels that are more localised than conventional ones, and remove information from selected physical scales while retaining the constraining power of the targeted range. Removing the scale of $k \geq 0.33~\mathrm{Mpc}^{-1}$ from the KiDS-Legacy pseudo-$C_\ell$ data vector, and using a covariance matrix whose Gaussian component is computed from the theoretical data vector, we find $S_8 = 0.798 \pm 0.045$. This agrees with both the fiducial KiDS-Legacy bandpower result and our no-$k$-cut pseudo-$C_\ell$ posterior to within $0.1σ$, indicating no significant bias from nonlinear astrophysical feedback at the precision of KiDS-Legacy. We also study the case in which the Gaussian covariance is computed from the observed data vector. In this setup, the same scale cut of $k < 0.33~\mathrm{Mpc}^{-1}$ gives a much lower $S_8=0.717_{-0.046}^{+0.047}$. Further $k$-cut tests reveal a mild scale-dependent trend, with larger physical scales preferring lower $S_8$ values and a maximum low- versus high-$k$ deviation of $1.80σ$. Mock tests show that this behaviour is not produced by the covariance prescription or data vector alone, but may arise from their interplay. These results show that BNT $k$-cuts provide both a mitigation strategy for nonlinear systematics and a diagnostic of weak-lensing inference pipelines.
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Submitted 5 July, 2026;
originally announced July 2026.
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KiDS-Legacy: Joint analysis of second- and third-order cosmic shear
Authors:
L. Linke,
L. Porth,
P. Burger,
J. Harnois-Déraps,
S. Heydenreich,
P. Schneider,
M. Asgari,
M. Bilicki,
C. Georgiou,
C. Heymans,
H. Hildebrandt,
H. Hoekstra,
P. Jalan,
B. Joachimi,
S. Joudaki,
K. Kuijken,
S. Li,
L. Moscardini,
M. Radovich,
R. Reischke,
B. Stölzner,
A. H. Wright,
Z. Yan,
Y. -H. Zhang
Abstract:
Weak lensing by large-scale structure is a powerful cosmological probe. While most analyses rely on second-order correlations, these are primarily sensitive to the parameter combination $S_8 = σ_8 (Ω_m/0.3)^{0.5}$, limiting their ability to constrain $Ω_m$ and other cosmological parameters independently. Higher-order statistics capture non-Gaussian features of the density field and can therefore b…
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Weak lensing by large-scale structure is a powerful cosmological probe. While most analyses rely on second-order correlations, these are primarily sensitive to the parameter combination $S_8 = σ_8 (Ω_m/0.3)^{0.5}$, limiting their ability to constrain $Ω_m$ and other cosmological parameters independently. Higher-order statistics capture non-Gaussian features of the density field and can therefore break parameter degeneracies and extract more cosmological information from weak lensing surveys. We present a joint analysis of second- and third-order cosmic shear in the final data release of the Kilo-Degree Survey (KiDS-Legacy). We combine COSEBIs (Complete Orthogonal Sets of E-/B-mode Integrals) at scales between 2' and 300' with third-order aperture mass moments at scales between 4' and 32' to perform a joint analysis of second- and third-order statistics. Compared to previous KiDS analyses, we implement several methodological advances: an intrinsic alignment model with redshift and mass dependence, a baryon correction model validated on multiple hydrodynamical simulations, and corrections for reduced shear and source clustering. Combining COSEBIs with third-order aperture mass statistics in KiDS-Legacy yields $Ω_m = 0.297^{+0.056}_{-0.040}$ and $S_8 = 0.806^{+0.025}_{-0.023}$, significantly tightening the $Ω_m$ constraints and more than doubling the figure of merit in the $Ω_m$--$S_8$ plane compared to the two-point analysis alone. The third-order measurements pass stringent internal consistency tests, are fully compatible with the KiDS-Legacy 2-point constraints, other 2+3-point lensing results and with Planck CMB measurements within $1σ$, providing no evidence for an $S_8$ tension and demonstrating the maturity of 3-point cosmic shear as a key probe for forthcoming surveys.
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Submitted 10 June, 2026;
originally announced June 2026.
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Propagating data-driven galaxy redshift distribution uncertainties in 3$\times$2-pt analyses
Authors:
Jaime Ruiz-Zapatero,
Qianjun Hang,
Yun-Hao Zhang,
Benjamin Joachimi,
Joe Zuntz,
Ian Harrison,
Carlos García-García,
Alex Malz,
Benjamin Stölzner,
the LSST Dark Energy Science Collaboration
Abstract:
Uncertainties in the radial distribution of galaxies, $\boldsymbol{n}(\boldsymbol{z})$, are one of the major contributions to the error budget of early Stage-IV galaxy survey analyses of weak gravitational lensing, galaxy clustering and galaxy-galaxy lensing (3$\times$2-pt). Based on ensembles of simulated $\boldsymbol{n}(\boldsymbol{z})$ including stochastic and systematic variations, we study th…
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Uncertainties in the radial distribution of galaxies, $\boldsymbol{n}(\boldsymbol{z})$, are one of the major contributions to the error budget of early Stage-IV galaxy survey analyses of weak gravitational lensing, galaxy clustering and galaxy-galaxy lensing (3$\times$2-pt). Based on ensembles of simulated $\boldsymbol{n}(\boldsymbol{z})$ including stochastic and systematic variations, we study the impact of four different $\boldsymbol{n}(\boldsymbol{z})$ uncertainty models: shifts, shifts & stretches, Gaussian processes (GP) and principal component analysis (PCA). Due to the high dimensionality of the latter models, we make use of state-of-the-art gradient-based inference methods as well as approximate analytical marginalisation schemes. Our results show that Stage-IV 3$\times$2-pt analyses must go beyond simple shift & stretch models. In particular, we advocate for the adoption of PCA models even in early Stage-IV surveys. Our results show that considering a five-parameters PCA model only degrades the constraint on the $S_{\rm 8}$ parameter by $5$ per cent with respect to the case when only a shift and a stretch parameter are included, while incurring half the bias in its constituents parameters, $Ω_{\rm m}$ and $σ_{\rm 8}$. We demonstrate that all models considered can be safely marginalised analytically, with speed-ups of up to a factor of 25 depending on the dimensionality of the model. This will allow Stage-IV analyses to safely include higher-dimensional $\boldsymbol{n}(\boldsymbol{z})$ uncertainty models in their analysis at negligible additional computational cost.
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Submitted 2 July, 2026; v1 submitted 27 April, 2026;
originally announced April 2026.
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KiDS-Legacy: WIMP dark matter constraints from the cross-correlation of weak lensing and Fermi-LAT gamma rays
Authors:
Shiyang Zhang,
Hendrik Hildebrandt,
Ziang Yan,
Tilman Tröster,
Athithya Aravinthan,
Marika Asgari,
Deaglan J. Bartlett,
Maciej Bilicki,
Dominik Elsässer,
Catherine Heymans,
Benjamin Joachimi,
Lauro Moscardini,
Dennis Neumann,
Anya Paopiamsap,
Robert Reischke,
Benjamin Stölzner
Abstract:
Dark matter dominates the matter content of the Universe, and its properties can be constrained through large-scale structure probes such as the cross-correlation between the unresolved gamma-ray background (UGRB) and weak gravitational lensing. We analysed 15 years of Fermi-LAT data, constructing UGRB intensity maps in ten energy bins (0.5-1000 GeV), and cross-correlated them with KiDS-Legacy she…
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Dark matter dominates the matter content of the Universe, and its properties can be constrained through large-scale structure probes such as the cross-correlation between the unresolved gamma-ray background (UGRB) and weak gravitational lensing. We analysed 15 years of Fermi-LAT data, constructing UGRB intensity maps in ten energy bins (0.5-1000 GeV), and cross-correlated them with KiDS-Legacy shear in six tomographic bins. The measurements were performed using angular power spectra estimated with the pseudo-$C_\ell$ method. No significant cross-correlation is found. Based on this non-detection, we present 95% upper bounds on the weakly interacting massive particle (WIMP) decay rate $Γ_{\rm dec}$ and velocity-averaged annihilation cross-section $\langleσ_{\rm ann} v\rangle$ as functions of mass. We compare our results with bounds from other cosmological tracers and from local probes, and found them to be complementary, particularly at low masses ($\rm GeV/TeV$). In addition, using a Euclid-like lensing survey cross-correlated with Fermi-LAT, we forecast $\sim$2 times tighter limits, highlighting the potential of forthcoming data to strengthen constraints on dark matter annihilation and decay.
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Submitted 19 January, 2026; v1 submitted 16 January, 2026;
originally announced January 2026.
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KiDS-Legacy: Constraining dark energy, neutrino mass, and curvature
Authors:
Robert Reischke,
Benjamin Stölzner,
Benjamin Joachimi,
Angus H. Wright,
Marika Asgari,
Maciej Bilicki,
Nora Elisa Chisari,
Andrej Dvornik,
Christos Georgiou,
Benjamin Giblin,
Joachim Harnois-Déraps,
Catherine Heymans,
Hendrik Hildebrandt,
Henk Hoekstra,
Shahab Joudaki,
Konrad Kuijken,
Shun-Sheng Li,
Laila Linke,
Arthur Loureiro,
Constance Mahony,
Lauro Moscardini,
Lucas Porth,
Mario Radovich,
Tilman Tröster,
Maximilian von Wietersheim-Kramsta
, et al. (3 additional authors not shown)
Abstract:
We constrained minimally extended cosmological models with the cosmic shear analysis of the final data release from the Kilo-Degree Survey (KiDS-Legacy) in combination with external probes. Due to the consistency of the KiDS-Legacy analysis with the cosmic microwave background (CMB), we could combine these datasets reliably for the first time. Additionally, we used CMB lensing, galaxy redshift-spa…
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We constrained minimally extended cosmological models with the cosmic shear analysis of the final data release from the Kilo-Degree Survey (KiDS-Legacy) in combination with external probes. Due to the consistency of the KiDS-Legacy analysis with the cosmic microwave background (CMB), we could combine these datasets reliably for the first time. Additionally, we used CMB lensing, galaxy redshift-space distortions, and baryon acoustic oscillations. We assessed, in turn, the effects of spatial curvature, varying neutrino masses, and an evolving dark energy component on cosmological constraints from KiDS-Legacy alone and from KiDS-Legacy combined with external probes. We find KiDS-Legacy to be consistent with the fiducial flat $Λ$-cold dark matter ($Λ$CDM) analysis with $c^2 \sum m_ν\leq 1.5\,$eV, $w_0 = -1.0\pm 0.7$, and $w_a = -1.3^{+1.9}_{-2.0}$ while $Ω_K = 0.08^{+0.16}_{-0.17}$ (1$σ$ bounds) with an almost equal goodness of fit. The $w_0w_a$CDM model is not a significant improvement over $Λ$CDM when cosmic shear and CMB lensing are combined, yielding a Bayes factor $B = 0.07$. If all probes are combined, however, $B$ increases to 2.73, corresponding to a $2.6σ$ suspiciousness tension. The constraint on $S_8 = σ_8\sqrt{Ω_\mathrm{m}/0.3}$ is robust to opening up the parameter space for cosmic shear. Adding all external datasets to KiDS-Legacy, we find $S_8 = 0.816 \pm 0.006$ in $Λ$CDM and $S_8 = 0.837 \pm 0.008$ in $w_0 w_a$CDM for all probes combined.
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Submitted 10 May, 2026; v1 submitted 11 December, 2025;
originally announced December 2025.
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KiDS-Legacy: Constraints on Horndeski gravity from weak lensing combined with galaxy clustering and cosmic microwave background anisotropies
Authors:
Benjamin Stölzner,
Robert Reischke,
Matteo Grasso,
Matteo Cataneo,
Benjamin Joachimi,
Arthur Loureiro,
Alessio Spurio Mancini,
Angus H. Wright,
Marika Asgari,
Maciej Bilicki,
Andrej Dvornik,
Christos Georgiou,
Benjamin Giblin,
Catherine Heymans,
Hendrik Hildebrandt,
Shahab Joudaki,
Konrad Kuijken,
Shun-Sheng Li,
Laila Linke,
Constance Mahony,
Lauro Moscardini,
Lucas Porth,
Mario Radovich,
Tilman Tröster,
Maximilian von Wietersheim-Kramsta
, et al. (3 additional authors not shown)
Abstract:
We present constraints on modified gravity from a cosmic shear analysis of the final data release of the Kilo-Degree Survey (KiDS-Legacy) in combination with DESI measurements of baryon acoustic oscillations, eBOSS observations of redshift space distortions, and cosmic microwave background anisotropies from Planck. We study the Horndeski class of modified gravity models in an effective field theor…
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We present constraints on modified gravity from a cosmic shear analysis of the final data release of the Kilo-Degree Survey (KiDS-Legacy) in combination with DESI measurements of baryon acoustic oscillations, eBOSS observations of redshift space distortions, and cosmic microwave background anisotropies from Planck. We study the Horndeski class of modified gravity models in an effective field theory framework employing a parameterisation that satisfies stability conditions by construction and, for the first time, present a cosmological analysis in this inherently stable parameter basis. Cosmic shear constrains the Horndeski parameter space significantly, matching or surpassing the CMB contribution. Adopting the de-mixed kinetic term of the scalar field perturbation, $D_{\rm kin}$, and the deviation of the Planck mass from its fiducial value, $ΔM_*^2\equiv M_*^2-1$, as model parameters, we constrain their present values to be $Δ\hat{M}_*^2=0.32^{+0.07}_{-0.21}$ and $\hat{D}_{\rm kin} = 3.74^{+0.69}_{-1.92}$, which deviate from general relativity at $1.5σ$ and $1.9σ$, respectively. We derive constraints on the structure growth parameter $S_8=0.813^{+0.008}_{-0.011}$, which is compatible with the $Λ$CDM constraint at $0.54σ$. We obtain the deviation of the effective Newtonian coupling from the GR value as $Δμ_{\infty,{\rm eff}}=0.066\pm0.023$, corresponding to a $2.9σ$ significance. Although modified gravity provides a slightly better fit to the data, a model comparison shows only a weak preference for modified gravity at the $1.4σ$ level. When adopting a dynamical dark energy model of the background cosmology, the inferred modified gravity parameter constraints are stable with respect to a $Λ$CDM background, while a mild preference at $1.57σ$ for dynamical dark energy remains.
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Submitted 24 March, 2026; v1 submitted 11 December, 2025;
originally announced December 2025.
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KiDS-1000 cosmic shear reanalysis using MetaCalibration
Authors:
Mijin Yoon,
Henk Hoekstra,
Shun-Sheng Li,
Konrad Kuijken,
Lance Miller,
Hendrik Hildebrandt,
Catherine Heymans,
Benjamin Joachimi,
Angus H. Wright,
Marika Asgari,
Jan Luca van den Busch,
Robert Reischke,
Benjamin Stölzner
Abstract:
A number of cosmic shear studies have reported results that are in mild tension with the Planck cosmic microwave measurement. To explore if this can be caused by biases in the shear estimation, we revisit the analysis of data from the Kilo-Degree Survey (KiDS) using an alternative shape measurement pipeline that is more robust to uncertainties in the calibration. To this end, we present an impleme…
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A number of cosmic shear studies have reported results that are in mild tension with the Planck cosmic microwave measurement. To explore if this can be caused by biases in the shear estimation, we revisit the analysis of data from the Kilo-Degree Survey (KiDS) using an alternative shape measurement pipeline that is more robust to uncertainties in the calibration. To this end, we present an implementation of MetaCalibration, and compare its performance to that of lensfit, which has been used in previous analyses of these data. We find that the multiplicative bias is reduced, especially for the most distant redshifts, as derived from multi-band image simulations designed to match the KiDS data (SURFS-based KiDS-Legacy-Like Simulations: SKiLLS). For all tomographic bins we obtain a multiplicative bias $|m|<0.017$, with negligible additive bias. Importantly, the calibration has a negligible sensitivity to key galaxy properties. The resulting robust shear estimates were used to obtain cosmological parameter constraints. We find that the parameter $S_8\equiv σ_8 \sqrt{Ω_\mathrm{m}/0.3} =0.789_{-0.024}^{+0.020}$ is consistent with the previous KiDS-1000 lensfit constraint of $S_8=0.776^{+0.029 +0.002}_{-0.027-0.003}$ (statistical + systematic errors). Thanks to the higher effective source density, the constraining power is improved by about 28%. The difference in $S_8$ with the Planck value remains at a similar level, 1.8$σ$, implying that it is not caused by the shear measurements.
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Submitted 1 October, 2025;
originally announced October 2025.
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Redshift Assessment Infrastructure Layers (RAIL): Rubin-era photometric redshift stress-testing and at-scale production
Authors:
The RAIL Team,
Jan Luca van den Busch,
Eric Charles,
Johann Cohen-Tanugi,
Alice Crafford,
John Franklin Crenshaw,
Sylvie Dagoret,
Josue De-Santiago,
Juan De Vicente,
Qianjun Hang,
Benjamin Joachimi,
Shahab Joudaki,
J. Bryce Kalmbach,
Arun Kannawadi,
Shuang Liang,
Olivia Lynn,
Alex I. Malz,
Rachel Mandelbaum,
Grant Merz,
Irene Moskowitz,
Drew Oldag,
Jaime Ruiz-Zapatero,
Mubdi Rahman,
Markus M. Rau,
Samuel J. Schmidt
, et al. (8 additional authors not shown)
Abstract:
Virtually all extragalactic use cases of the Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST) require the use of galaxy redshift information, yet the vast majority of its sample of tens of billions of galaxies will lack high-fidelity spectroscopic measurements thereof, instead relying on photometric redshifts (photo-$z$) subject to systematic imprecision and inaccuracy best encap…
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Virtually all extragalactic use cases of the Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST) require the use of galaxy redshift information, yet the vast majority of its sample of tens of billions of galaxies will lack high-fidelity spectroscopic measurements thereof, instead relying on photometric redshifts (photo-$z$) subject to systematic imprecision and inaccuracy best encapsulated by photo-$z$ probability density functions (PDFs). We present the version 1 release of Redshift Assessment Infrastructure Layers (RAIL), an open source Python library for at-scale probabilistic photo-$z$ estimation, initiated by the LSST Dark Energy Science Collaboration (DESC) with contributions from the LSST Interdisciplinary Network for Collaboration and Computing (LINCC) Frameworks team. RAIL's three subpackages provide modular tools for end-to-end stress-testing, including a forward modeling suite to generate realistically complex photometry, a unified API for estimating per-galaxy and ensemble redshift PDFs by an extensible set of algorithms, and built-in metrics of both photo-$z$ PDFs and point estimates. RAIL serves as a flexible toolkit enabling the derivation and optimization of photo-$z$ data products at scale for a variety of science goals and is not specific to LSST data. We thus describe to the extragalactic science community, including and beyond Rubin the design and functionality of the RAIL software library so that any researcher may have access to its wide array of photo-$z$ characterization and assessment tools.
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Submitted 12 March, 2026; v1 submitted 5 May, 2025;
originally announced May 2025.
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KiDS-Legacy: Consistency of cosmic shear measurements and joint cosmological constraints with external probes
Authors:
Benjamin Stölzner,
Angus H. Wright,
Marika Asgari,
Catherine Heymans,
Hendrik Hildebrandt,
Henk Hoekstra,
Benjamin Joachimi,
Konrad Kuijken,
Shun-Sheng Li,
Constance Mahony,
Robert Reischke,
Mijin Yoon,
Maciej Bilicki,
Pierre Burger,
Nora Elisa Chisari,
Andrej Dvornik,
Christos Georgiou,
Benjamin Giblin,
Joachim Harnois-Déraps,
Priyanka Jalan,
Anjitha John William,
Shahab Joudaki,
Giorgio Francesco Lesci,
Laila Linke,
Arthur Loureiro
, et al. (11 additional authors not shown)
Abstract:
We present a cosmic shear consistency analysis of the final data release from the Kilo-Degree Survey (KiDS-Legacy). By adopting three tiers of consistency metrics, we compare cosmological constraints between subsets of the KiDS-Legacy dataset split by redshift, angular scale, galaxy colour and spatial region. We also review a range of two-point cosmic shear statistics. With the data passing all ou…
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We present a cosmic shear consistency analysis of the final data release from the Kilo-Degree Survey (KiDS-Legacy). By adopting three tiers of consistency metrics, we compare cosmological constraints between subsets of the KiDS-Legacy dataset split by redshift, angular scale, galaxy colour and spatial region. We also review a range of two-point cosmic shear statistics. With the data passing all our consistency metric tests, we demonstrate that KiDS-Legacy is the most internally consistent KiDS catalogue to date. In a joint cosmological analysis of KiDS-Legacy and DES Y3 cosmic shear, combined with data from the Pantheon+ Type Ia supernovae compilation and baryon acoustic oscillations from DESI Y1, we find constraints consistent with Planck measurements of the cosmic microwave background with $S_8\equiv σ_8\sqrt{Ω_{\rm m}/0.3} = 0.814^{+0.011}_{-0.012}$ and $σ_8 = 0.802^{+0.022}_{-0.018}$.
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Submitted 20 October, 2025; v1 submitted 25 March, 2025;
originally announced March 2025.
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KiDS-Legacy: Cosmological constraints from cosmic shear with the complete Kilo-Degree Survey
Authors:
Angus H. Wright,
Benjamin Stölzner,
Marika Asgari,
Maciej Bilicki,
Benjamin Giblin,
Catherine Heymans,
Hendrik Hildebrandt,
Henk Hoekstra,
Benjamin Joachimi,
Konrad Kuijken,
Shun-Sheng Li,
Robert Reischke,
Maximilian von Wietersheim-Kramsta,
Mijin Yoon,
Pierre Burger,
Nora Elisa Chisari,
Jelte de Jong,
Andrej Dvornik,
Christos Georgiou,
Joachim Harnois-Déraps,
Priyanka Jalan,
Anjitha John William,
Shahab Joudaki,
Giorgio Francesco Lesci,
Laila Linke
, et al. (13 additional authors not shown)
Abstract:
We present cosmic shear constraints from the completed Kilo-Degree Survey (KiDS), where the cosmological parameter $S_8\equivσ_8\sqrt{Ω_{\rm m}/0.3} = 0.815^{+0.016}_{-0.021}$, is found to be in agreement ($0.73σ$) with results from the Planck Legacy cosmic microwave background experiment. The final KiDS footprint spans $1347$ square degrees of deep nine-band imaging across the optical and near-in…
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We present cosmic shear constraints from the completed Kilo-Degree Survey (KiDS), where the cosmological parameter $S_8\equivσ_8\sqrt{Ω_{\rm m}/0.3} = 0.815^{+0.016}_{-0.021}$, is found to be in agreement ($0.73σ$) with results from the Planck Legacy cosmic microwave background experiment. The final KiDS footprint spans $1347$ square degrees of deep nine-band imaging across the optical and near-infrared, along with an extra $23$ square degrees of KiDS-like calibration observations of deep spectroscopic surveys. Improvements in our redshift distribution estimation methodology, combined with our enhanced calibration data and multi-band image simulations, allow us to extend our lensed sample out to a photometric redshift of $z_{\rm B}\leq2.0$. Compared to previous KiDS analyses, the increased survey area and redshift depth results in a $\sim32\%$ improvement in constraining power in terms of $Σ_8\equivσ_8\left(Ω_{\rm m}/0.3\right)^α= 0.821^{+0.014}_{-0.016}$, where $α= 0.58$ has been optimised to match the revised degeneracy direction of $σ_8$ and $Ω_{\rm m}$. We adopt a new physically motivated intrinsic alignment model that depends jointly on the galaxy sample's halo mass and spectral type distributions, and that is informed by previous direct alignment measurements. We also marginalise over our uncertainty on the impact of baryon feedback on the non-linear matter power spectrum. Comparing to previous KiDS analyses, we conclude that the increase seen in $S_8$ primarily results from our improved redshift distribution estimation and calibration, as well as new survey area and improved image reduction. Our companion paper Stölzner et al. (submitted) presents a full suite of internal and external consistency tests, finding the KiDS-Legacy data set to be the most internally robust sample produced by KiDS to date.
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Submitted 21 October, 2025; v1 submitted 25 March, 2025;
originally announced March 2025.
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KiDS-Legacy: Redshift distributions and their calibration
Authors:
Angus H. Wright,
Hendrik Hildebrandt,
Jan Luca van den Busch,
Maciej Bilicki,
Catherine Heymans,
Benjamin Joachimi,
Constance Mahony,
Robert Reischke,
Benjamin Stölzner,
Anna Wittje,
Marika Asgari,
Nora Elisa Chisari,
Andrej Dvornik,
Christos Georgiou,
Benjamin Giblin,
Henk Hoekstra,
Priyanka Jalan,
Anjitha John William,
Shahab Joudaki,
Konrad Kuijken,
Giorgio Francesco Lesci,
Shun-Sheng Li,
Laila Linke,
Arthur Loureiro,
Matteo Maturi
, et al. (8 additional authors not shown)
Abstract:
We present the redshift calibration methodology and bias estimates for the cosmic shear analysis of the fifth and final data release (DR5) of the Kilo-Degree Survey (KiDS). KiDS-DR5 includes a greatly expanded compilation of calibrating spectra, drawn from $27$ square degrees of dedicated optical and near-IR imaging taken over deep spectroscopic fields. The redshift distribution calibration levera…
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We present the redshift calibration methodology and bias estimates for the cosmic shear analysis of the fifth and final data release (DR5) of the Kilo-Degree Survey (KiDS). KiDS-DR5 includes a greatly expanded compilation of calibrating spectra, drawn from $27$ square degrees of dedicated optical and near-IR imaging taken over deep spectroscopic fields. The redshift distribution calibration leverages a range of new methods and updated simulations to produce the most precise $N(z)$ bias estimates used by KiDS to date. Improvements to our colour-based redshift distribution measurement method (SOM) mean that we are able to use many more sources per tomographic bin for our cosmological analyses, and better estimate the representation of our source sample given the available spec-$z$. We validate our colour-based redshift distribution estimates with spectroscopic cross-correlations (CC). We find that improvements to our cross-correlation redshift distribution measurement methods mean that redshift distribution biases estimated between the SOM and CC methods are fully consistent on simulations, and the data calibration is consistent to better than $2σ$ in all tomographic bins.
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Submitted 21 October, 2025; v1 submitted 25 March, 2025;
originally announced March 2025.
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The fifth data release of the Kilo Degree Survey: Multi-epoch optical/NIR imaging covering wide and legacy-calibration fields
Authors:
Angus H. Wright,
Konrad Kuijken,
Hendrik Hildebrandt,
Mario Radovich,
Maciej Bilicki,
Andrej Dvornik,
Fedor Getman,
Catherine Heymans,
Henk Hoekstra,
Shun-Sheng Li,
Lance Miller,
Nicola R. Napolitano,
Qianli Xia,
Marika Asgari,
Massimo Brescia,
Hugo Buddelmeijer,
Pierre Burger,
Gianluca Castignani,
Stefano Cavuoti,
Jelte de Jong,
Alastair Edge,
Benjamin Giblin,
Carlo Giocoli,
Joachim Harnois-Déraps,
Priyanka Jalan
, et al. (29 additional authors not shown)
Abstract:
We present the final data release of the Kilo-Degree Survey (KiDS-DR5), a public European Southern Observatory (ESO) wide-field imaging survey optimised for weak gravitational lensing studies. We combined matched-depth multi-wavelength observations from the VLT Survey Telescope and the VISTA Kilo-degree INfrared Galaxy (VIKING) survey to create a nine-band optical-to-near-infrared survey spanning…
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We present the final data release of the Kilo-Degree Survey (KiDS-DR5), a public European Southern Observatory (ESO) wide-field imaging survey optimised for weak gravitational lensing studies. We combined matched-depth multi-wavelength observations from the VLT Survey Telescope and the VISTA Kilo-degree INfrared Galaxy (VIKING) survey to create a nine-band optical-to-near-infrared survey spanning $1347$ deg$^2$. The median $r$-band $5σ$ limiting magnitude is 24.8 with median seeing $0.7^{\prime\prime}$. The main survey footprint includes $4$ deg$^2$ of overlap with existing deep spectroscopic surveys. We complemented these data in DR5 with a targeted campaign to secure an additional $23$ deg$^2$ of KiDS- and VIKING-like imaging over a range of additional deep spectroscopic survey fields. From these fields, we extracted a catalogue of $126\,085$ sources with both spectroscopic and photometric redshift information, which enables the robust calibration of photometric redshifts across the full survey footprint. In comparison to previous releases, DR5 represents a $34\%$ areal extension and includes an $i$-band re-observation of the full footprint, thereby increasing the effective $i$-band depth by $0.4$ magnitudes and enabling multi-epoch science. Our processed nine-band imaging, single- and multi-band catalogues with masks, and homogenised photometry and photometric redshifts can be accessed through the ESO Archive Science Portal.
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Submitted 25 March, 2025;
originally announced March 2025.
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KiDS-Legacy: Angular galaxy clustering from deep surveys with complex selection effects
Authors:
Ziang Yan,
Angus H. Wright,
Nora Elisa Chisari,
Christos Georgiou,
Shahab Joudaki,
Arthur Loureiro,
Robert Reischke,
Marika Asgari,
Maciej Bilicki,
Andrej Dvornik,
Catherine Heymans,
Hendrik Hildebrandt,
Priyanka Jalan,
Benjamin Joachimi,
Giorgio Francesco Lesci,
Shun-Sheng Li,
Laila Linke,
Constance Mahony,
Lauro Moscardini,
Nicola R. Napolitano,
Benjamin Stoelzner,
Maximilian Von Wietersheim-Kramsta,
Mijin Yoon
Abstract:
Photometric galaxy surveys, despite their limited resolution along the line of sight, encode rich information about the large-scale structure (LSS) of the Universe thanks to the high number density and extensive depth of the data. However, the complicated selection effects in wide and deep surveys can potentially cause significant bias in the angular two-point correlation function (2PCF) measured…
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Photometric galaxy surveys, despite their limited resolution along the line of sight, encode rich information about the large-scale structure (LSS) of the Universe thanks to the high number density and extensive depth of the data. However, the complicated selection effects in wide and deep surveys can potentially cause significant bias in the angular two-point correlation function (2PCF) measured from those surveys. In this paper, we measure the 2PCF from the newly published KiDS-Legacy sample. Given an $r$-band $5σ$ magnitude limit of $24.8$ and survey footprint of $1347$ deg$^2$, it achieves an excellent combination of sky coverage and depth for such a measurement. We find that complex selection effects, primarily induced by varying seeing, introduce over-estimation of the 2PCF by approximately an order of magnitude. To correct for such effects, we apply a machine learning-based method to recover an organised random (OR) that presents the same selection pattern as the galaxy sample. The basic idea is to find the selection-induced clustering of galaxies using a combination of self-organising maps (SOMs) and hierarchical clustering (HC). This unsupervised machine learning method is able to recover complicated selection effects without specifying their functional forms. We validate this SOM+HC method on mock deep galaxy samples with realistic systematics and selections derived from the KiDS-Legacy catalogue. Using mock data, we demonstrate that the OR delivers unbiased 2PCF cosmological parameter constraints, removing the $27σ$ offset in the galaxy bias parameter that is recovered when adopting uniform randoms. Blinded measurements on the real KiDS-Legacy data show that the corrected 2PCF is robust to the SOM+HC configuration near the optimal set-up suggested by the mock tests.
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Submitted 3 February, 2025; v1 submitted 30 October, 2024;
originally announced October 2024.
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KiDS-Legacy: Covariance validation and the unified OneCovariance framework for projected large-scale structure observables
Authors:
Robert Reischke,
Sandra Unruh,
Marika Asgari,
Andrej Dvornik,
Hendrik Hildebrandt,
Benjamin Joachimi,
Lucas Porth,
Maximilian von Wietersheim-Kramsta,
Jan Luca van den Busch,
Benjamin Stölzner,
Angus H. Wright,
Ziang Yan,
Maciej Bilicki,
Pierre Burger,
Nora Elisa Chisari,
Joachim Harnois-Deraps,
Christos Georgiou,
Catherine Heymans,
Priyanka Jalan,
Shahab Joudaki,
Konrad Kuijken,
Shun-Sheng Li,
Laila Linke,
Constance Mahony,
Davide Sciotti
, et al. (2 additional authors not shown)
Abstract:
We introduce OneCovariance, an open-source software designed to accurately compute covariance matrices for an arbitrary set of two-point summary statistics across a variety of large-scale structure tracers. Utilising the halo model, we estimated the statistical properties of matter and biased tracer fields, incorporating all Gaussian, non-Gaussian, and super-sample covariance terms. The flexible c…
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We introduce OneCovariance, an open-source software designed to accurately compute covariance matrices for an arbitrary set of two-point summary statistics across a variety of large-scale structure tracers. Utilising the halo model, we estimated the statistical properties of matter and biased tracer fields, incorporating all Gaussian, non-Gaussian, and super-sample covariance terms. The flexible configuration permits user-specific parameters, such as the complexity of survey geometry, the halo occupation distribution employed to define each galaxy sample, or the form of the real-space and/or Fourier space statistics to be analysed. We illustrate the capabilities of OneCovariance within the context of a cosmic shear analysis of the final data release of the Kilo-Degree Survey (KiDS-Legacy). Upon comparing our estimated covariance with measurements from mock data and calculations from independent software, we ascertain that OneCovariance achieves accuracy at the per cent level. When assessing the impact of ignoring complex survey geometry in the cosmic shear covariance computation, we discover misestimations at approximately the $10\%$ level for cosmic variance terms. Nonetheless, these discrepancies do not significantly affect the KiDS-Legacy recovery of cosmological parameters. We derive the cross-covariance between real-space correlation functions, bandpowers, and COSEBIs, facilitating future consistency tests among these three cosmic shear statistics. Additionally, we calculate the covariance matrix of photometric-spectroscopic galaxy clustering measurements, validating the jackknife covariance estimates for calibrating KiDS-Legacy redshift distributions. The OneCovariance can be found on GitHub, together with comprehensive documentation and examples.
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Submitted 16 September, 2025; v1 submitted 9 October, 2024;
originally announced October 2024.
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6x2pt: Forecasting gains from joint weak lensing and galaxy clustering analyses with spectroscopic-photometric galaxy cross-correlations
Authors:
Harry Johnston,
Nora Elisa Chisari,
Shahab Joudaki,
Robert Reischke,
Benjamin Stölzner,
Arthur Loureiro,
Constance Mahony,
Sandra Unruh,
Angus H. Wright,
Marika Asgari,
Maciej Bilicki,
Pierre Burger,
Andrej Dvornik,
Christos Georgiou,
Benjamin Giblin,
Catherine Heymans,
Hendrik Hildebrandt,
Benjamin Joachimi,
Konrad Kuijken,
Shun-Sheng Li,
Laila Linke,
Lucas Porth,
HuanYuan Shan,
Tilman Tröster,
Jan Luca van den Busch
, et al. (3 additional authors not shown)
Abstract:
We explore the enhanced self-calibration of photometric galaxy redshift distributions, $n(z)$, through the combination of up to six two-point functions. Our $\rm 3\times2pt$ configuration is comprised of photometric shear, spectroscopic galaxy clustering, and spectroscopic-photometric galaxy-galaxy lensing (GGL). We further include spectroscopic-photometric cross-clustering; photometric GGL; and p…
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We explore the enhanced self-calibration of photometric galaxy redshift distributions, $n(z)$, through the combination of up to six two-point functions. Our $\rm 3\times2pt$ configuration is comprised of photometric shear, spectroscopic galaxy clustering, and spectroscopic-photometric galaxy-galaxy lensing (GGL). We further include spectroscopic-photometric cross-clustering; photometric GGL; and photometric auto-clustering, using the photometric shear sample as density tracer. We perform simulated likelihood forecasts of the cosmological and nuisance parameter constraints for Stage-III- and Stage-IV-like surveys. For the Stage-III-like case, we employ realistic but perturbed redshift distributions, and distinguish between "coherent" shifting in one direction, versus more internal scattering and full-shape errors. For perfectly known $n(z)$, a $\rm 6\times2pt$ analysis gains $\sim40\%$ in Figure of Merit (FoM) in the $S_8\equivσ_8\sqrt{Ω_{\rm m}/0.3}$ and $Ω_{\rm m}$ plane relative to the $\rm 3\times2pt$ analysis. If untreated, coherent and incoherent redshift errors lead to inaccurate inferences of $S_8$ and $Ω_{\rm m}$, respectively. Employing bin-wise scalar shifts $δ{z}_i$ in the tomographic mean redshifts reduces cosmological parameter biases, with a $\rm 6x2pt$ analysis constraining the shift parameters with $2-4$ times the precision of a photometric $\rm 3^{ph}\times2pt$ analysis. For the Stage-IV-like survey, a $\rm 6\times2pt$ analysis doubles the FoM($σ_8{-}Ω_{\rm m}$) compared to any $\rm 3\times2pt$ or $\rm 3^{ph}\times2pt$ analysis, and is only $8\%$ less constraining than if the $n(z)$ were perfectly known. A Gaussian mixture model for the $n(z)$ reduces mean-redshift errors and preserves the $n(z)$ shape. It also yields the most accurate and precise cosmological constraints for any $N\rm\times2pt$ configuration given $n(z)$ biases.
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Submitted 25 September, 2024;
originally announced September 2024.
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DES Y3 + KiDS-1000: Consistent cosmology combining cosmic shear surveys
Authors:
Dark Energy Survey,
Kilo-Degree Survey Collaboration,
:,
T. M. C. Abbott,
M. Aguena,
A. Alarcon,
O. Alves,
A. Amon,
F. Andrade-Oliveira,
M. Asgari,
S. Avila,
D. Bacon,
K. Bechtol,
M. R. Becker,
G. M. Bernstein,
E. Bertin,
M. Bilicki,
J. Blazek,
S. Bocquet,
D. Brooks,
P. Burger,
D. L. Burke,
H. Camacho,
A. Campos,
A. Carnero Rosell
, et al. (138 additional authors not shown)
Abstract:
We present a joint cosmic shear analysis of the Dark Energy Survey (DES Y3) and the Kilo-Degree Survey (KiDS-1000) in a collaborative effort between the two survey teams. We find consistent cosmological parameter constraints between DES Y3 and KiDS-1000 which, when combined in a joint-survey analysis, constrain the parameter $S_8 = σ_8 \sqrt{Ω_{\rm m}/0.3}$ with a mean value of…
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We present a joint cosmic shear analysis of the Dark Energy Survey (DES Y3) and the Kilo-Degree Survey (KiDS-1000) in a collaborative effort between the two survey teams. We find consistent cosmological parameter constraints between DES Y3 and KiDS-1000 which, when combined in a joint-survey analysis, constrain the parameter $S_8 = σ_8 \sqrt{Ω_{\rm m}/0.3}$ with a mean value of $0.790^{+0.018}_{-0.014}$. The mean marginal is lower than the maximum a posteriori estimate, $S_8=0.801$, owing to skewness in the marginal distribution and projection effects in the multi-dimensional parameter space. Our results are consistent with $S_8$ constraints from observations of the cosmic microwave background by Planck, with agreement at the $1.7σ$ level. We use a Hybrid analysis pipeline, defined from a mock survey study quantifying the impact of the different analysis choices originally adopted by each survey team. We review intrinsic alignment models, baryon feedback mitigation strategies, priors, samplers and models of the non-linear matter power spectrum.
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Submitted 19 October, 2023; v1 submitted 26 May, 2023;
originally announced May 2023.
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Optimising the shape of photometric redshift distributions with clustering cross-correlations
Authors:
Benjamin Stölzner,
Benjamin Joachimi,
Andreas Korn,
the LSST Dark Energy Science Collaboration
Abstract:
We present an optimisation method for the assignment of photometric galaxies into a chosen set of redshift bins. This is achieved by combining simulated annealing, an optimisation algorithm inspired by solid-state physics, with an unsupervised machine learning method, a self-organising map (SOM) of the observed colours of galaxies. Starting with a sample of galaxies that is divided into redshift b…
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We present an optimisation method for the assignment of photometric galaxies into a chosen set of redshift bins. This is achieved by combining simulated annealing, an optimisation algorithm inspired by solid-state physics, with an unsupervised machine learning method, a self-organising map (SOM) of the observed colours of galaxies. Starting with a sample of galaxies that is divided into redshift bins based on a photometric redshift point estimate, the simulated annealing algorithm repeatedly reassigns SOM-selected subsamples of galaxies, which are close in colour, to alternative redshift bins. We optimise the clustering cross-correlation signal between photometric galaxies and a reference sample of galaxies with well-calibrated redshifts. Depending on the effect on the clustering signal, the reassignment is either accepted or rejected. By dynamically increasing the resolution of the SOM, the algorithm eventually converges to a solution that minimises the number of mismatched galaxies in each tomographic redshift bin and thus improves the compactness of their corresponding redshift distribution. This method is demonstrated on the synthetic LSST cosmoDC2 catalogue. We find a significant decrease in the fraction of catastrophic outliers in the redshift distribution in all tomographic bins, most notably in the highest redshift bin with a decrease in the outlier fraction from 57 per cent to 16 per cent.
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Submitted 7 February, 2023; v1 submitted 26 May, 2022;
originally announced May 2022.
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KiDS & Euclid: Cosmological implications of a pseudo angular power spectrum analysis of KiDS-1000 cosmic shear tomography
Authors:
A. Loureiro,
L. Whittaker,
A. Spurio Mancini,
B. Joachimi,
A. Cuceu,
M. Asgari,
B. Stölzner,
T. Tröster,
A. H. Wright,
M. Bilicki,
A. Dvornik,
B. Giblin,
C. Heymans,
H. Hildebrandt,
H. Shan,
A. Amara,
N. Auricchio,
C. Bodendorf,
D. Bonino,
E. Branchini,
M. Brescia,
V. Capobianco,
C. Carbone,
J. Carretero,
M. Castellano
, et al. (89 additional authors not shown)
Abstract:
We present a tomographic weak lensing analysis of the Kilo Degree Survey Data Release 4 (KiDS-1000), using a new pseudo angular power spectrum estimator (pseudo-$C_{\ell}$) under development for the ESA Euclid mission. Over 21 million galaxies with shape information are divided into five tomographic redshift bins, ranging from 0.1 to 1.2 in photometric redshift. We measured pseudo-$C_{\ell}$ using…
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We present a tomographic weak lensing analysis of the Kilo Degree Survey Data Release 4 (KiDS-1000), using a new pseudo angular power spectrum estimator (pseudo-$C_{\ell}$) under development for the ESA Euclid mission. Over 21 million galaxies with shape information are divided into five tomographic redshift bins, ranging from 0.1 to 1.2 in photometric redshift. We measured pseudo-$C_{\ell}$ using eight bands in the multipole range $76<\ell<1500$ for auto- and cross-power spectra between the tomographic bins. A series of tests were carried out to check for systematic contamination from a variety of observational sources including stellar number density, variations in survey depth, and point spread function properties. While some marginal correlations with these systematic tracers were observed, there is no evidence of bias in the cosmological inference. B-mode power spectra are consistent with zero signal, with no significant residual contamination from E/B-mode leakage. We performed a Bayesian analysis of the pseudo-$C_{\ell}$ estimates by forward modelling the effects of the mask. Assuming a spatially flat $Λ$CDM cosmology, we constrained the structure growth parameter $S_8 = σ_8(Ω_{\rm m}/0.3)^{1/2} = 0.754_{-0.029}^{+0.027}$. When combining cosmic shear from KiDS-1000 with baryon acoustic oscillation and redshift space distortion data from recent Sloan Digital Sky Survey (SDSS) measurements of luminous red galaxies, as well as the Lyman-$α$ forest and its cross-correlation with quasars, we tightened these constraints to $S_8 = 0.771^{+0.006}_{-0.032}$. These results are in very good agreement with previous KiDS-1000 and SDSS analyses and confirm a $\sim 3σ$ tension with early-Universe constraints from cosmic microwave background experiments.
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Submitted 4 July, 2022; v1 submitted 13 October, 2021;
originally announced October 2021.
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Geometry vs growth: Internal consistency of the flat ΛCDM model with KiDS-1000
Authors:
J. Ruiz-Zapatero,
Benjamin Stölzner,
Benjamin Joachimi,
Marika Asgari,
Maciej Bilicki,
Andrej Dvornik,
Benjamin Giblin,
Catherine Heymans,
Hendrik Hildebrandt,
Arun Kannawadi,
Konrad Kuijken,
TilmanTröster,
Jan Luca van den Busch,
Angus H. Wright
Abstract:
We carry out a multi-probe self-consistency test of the flat $Λ$CDM model with the aim of exploring potential causes of the reported tensions between high- and low-redshift cosmological observations. We divide the model into two theory regimes determined by the smooth background (geometry) and the evolution of matter density fluctuations (growth), each governed by an independent set of Lambda Cold…
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We carry out a multi-probe self-consistency test of the flat $Λ$CDM model with the aim of exploring potential causes of the reported tensions between high- and low-redshift cosmological observations. We divide the model into two theory regimes determined by the smooth background (geometry) and the evolution of matter density fluctuations (growth), each governed by an independent set of Lambda Cold Dark Matter ($Λ$CDM) cosmological parameters. This extended model is constrained by a combination of weak gravitational lensing measurements from the Kilo-Degree Survey, galaxy clustering signatures extracted from Sloan Digital Sky Survey campaigns and the Six-Degree Field Galaxy Survey, and the angular baryon acoustic scale and the primordial scalar fluctuation power spectrum measured in $\textit{Planck}$ cosmic microwave background (CMB) data. We find strong consistency between the geometry and growth parameters, and with the posterior of standard $Λ$CDM analysis. Tension in the amplitude of matter density fluctuations as measured by the parameter $S_8$ persists at around 3$σ$, with a $1.5\,\%$ constraint of $S_8 = 0.776_{-0.008}^{+0.016}$ for the combined probes. We also observe a less significant preference (at least $2σ$) for higher values of the Hubble constant, $H_0 = 70.5^{+0.7}_{-1.5}\,{\rm km\, s^{-1} Mpc^{-1}}$, as well as for lower values of the total matter density parameter $Ω_{\rm{m}} = 0.289^{+0.007}_{-0.005}$ compared to the full $\textit{Planck}$ analysis. Including the subset of the CMB information in the probe combination enhances these differences rather than alleviate them, which we link to the discrepancy between low and high multipoles in $\textit{Planck}$ data.
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Submitted 8 September, 2021; v1 submitted 20 May, 2021;
originally announced May 2021.
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Self-calibration and robust propagation of photometric redshift distribution uncertainties in weak gravitational lensing
Authors:
B. Stölzner,
B. Joachimi,
A. Korn,
H. Hildebrandt,
A. H. Wright
Abstract:
We present a method that accurately propagates residual uncertainties in photometric redshift distributions into the cosmological inference from weak lensing measurements. The redshift distributions of tomographic redshift bins are parameterised using a flexible modified Gaussian mixture model. We fit this model to pre-calibrated redshift distributions and implement an analytic marginalisation ove…
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We present a method that accurately propagates residual uncertainties in photometric redshift distributions into the cosmological inference from weak lensing measurements. The redshift distributions of tomographic redshift bins are parameterised using a flexible modified Gaussian mixture model. We fit this model to pre-calibrated redshift distributions and implement an analytic marginalisation over the potentially several hundred redshift nuisance parameters in the weak lensing likelihood, which is demonstrated to accurately recover the cosmological posterior. By iteratively fitting cosmological and nuisance parameters arising from the redshift distribution model, we perform a self-calibration of the redshift distributions via the tomographic cosmic shear measurements. Our method is applied to the third data release of the Kilo-Degree Survey combined with the VISTA Kilo-Degree Infrared Galaxy Survey (KV450). We find constraints on cosmological parameters that are in very good agreement with the fiducial KV450 cosmic shear analysis and investigate the effects of the more flexible model on the self-calibrated redshift distributions. We observe posterior shifts of the medians of the five tomographic redshift distributions of up to $Δz \approx 0.02$, which are however degenerate with an observed decrease of the amplitude of intrinsic galaxy alignments by about $10\%$.
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Submitted 7 May, 2021; v1 submitted 14 December, 2020;
originally announced December 2020.
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KiDS-1000 Cosmology: Cosmic shear constraints and comparison between two point statistics
Authors:
Marika Asgari,
Chieh-An Lin,
Benjamin Joachimi,
Benjamin Giblin,
Catherine Heymans,
Hendrik Hildebrandt,
Arun Kannawadi,
Benjamin Stölzner,
Tilman Tröster,
Jan Luca van den Busch,
Angus H. Wright,
Maciej Bilicki,
Chris Blake,
Jelte de Jong,
Andrej Dvornik,
Thomas Erben,
Fedor Getman,
Henk Hoekstra,
Fabian Köhlinger,
Konrad Kuijken,
Lance Miller,
Mario Radovich,
Peter Schneider,
HuanYuan Shan,
Edwin Valentijn
Abstract:
We present cosmological constraints from a cosmic shear analysis of the fourth data release of the Kilo-Degree Survey (KiDS-1000), doubling the survey area with nine-band optical and near-infrared photometry with respect to previous KiDS analyses. Adopting a spatially flat $Λ$CDM model, we find $S_8 = σ_8 (Ω_{\rm m}/0.3)^{0.5} = 0.759^{+0.024}_{-0.021}$ for our fiducial analysis, which is in $3σ$…
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We present cosmological constraints from a cosmic shear analysis of the fourth data release of the Kilo-Degree Survey (KiDS-1000), doubling the survey area with nine-band optical and near-infrared photometry with respect to previous KiDS analyses. Adopting a spatially flat $Λ$CDM model, we find $S_8 = σ_8 (Ω_{\rm m}/0.3)^{0.5} = 0.759^{+0.024}_{-0.021}$ for our fiducial analysis, which is in $3σ$ tension with the prediction of the Planck Legacy analysis of the cosmic microwave background. We compare our fiducial COSEBIs (Complete Orthogonal Sets of E/B-Integrals) analysis with complementary analyses of the two-point shear correlation function and band power spectra, finding results to be in excellent agreement. We investigate the sensitivity of all three statistics to a number of measurement, astrophysical, and modelling systematics, finding our $S_8$ constraints to be robust and dominated by statistical errors. Our cosmological analysis of different divisions of the data pass the Bayesian internal consistency tests, with the exception of the second tomographic bin. As this bin encompasses low redshift galaxies, carrying insignificant levels of cosmological information, we find that our results are unchanged by the inclusion or exclusion of this sample.
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Submitted 13 October, 2020; v1 submitted 30 July, 2020;
originally announced July 2020.
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An Updated Tomographic Analysis of the Integrated Sachs-Wolfe Effect and implications for Dark Energy
Authors:
Benjamin Stölzner,
Alessandro Cuoco,
Julien Lesgourgues,
Maciej Bilicki
Abstract:
We derive updated constraints on the Integrated Sachs-Wolfe (ISW) effect through cross-correlation of the cosmic microwave background with galaxy surveys. We improve with respect to similar previous analyses in several ways. First, we use the most recent versions of extragalactic object catalogs: SDSS DR12 photometric redshift (photo-$z$) and 2MASS Photo-$z$ datasets, as well as employed earlier f…
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We derive updated constraints on the Integrated Sachs-Wolfe (ISW) effect through cross-correlation of the cosmic microwave background with galaxy surveys. We improve with respect to similar previous analyses in several ways. First, we use the most recent versions of extragalactic object catalogs: SDSS DR12 photometric redshift (photo-$z$) and 2MASS Photo-$z$ datasets, as well as employed earlier for ISW, SDSS QSO photo-$z$ and NVSS samples. Second, we use for the first time the WISE~$\times$~SuperCOSMOS catalog, which allows us to perform an all-sky analysis of the ISW up to $z\sim0.4$. Third, thanks to the use of photo-$z$s, we separate each dataset into different redshift bins, deriving the cross-correlation in each bin. This last step leads to a significant improvement in sensitivity. We remove cross-correlation between catalogs using masks which mutually exclude common regions of the sky. We use two methods to quantify the significance of the ISW effect. In the first one, we fix the cosmological model, derive linear galaxy biases of the catalogs, and then evaluate the significance of the ISW using a single parameter. In the second approach we perform a global fit of the ISW and of the galaxy biases varying the cosmological model. We find significances of the ISW in the range 4.7-5.0 $σ$ thus reaching, for the first time in such an analysis, the threshold of 5 $σ$. Without the redshift tomography we find a significance of $\sim$ 4.0 $σ$, which shows the importance of the binning method. Finally we use the ISW data to infer constraints on the Dark Energy redshift evolution and equation of state. We find that the redshift range covered by the catalogs is still not optimal to derive strong constraints, although this goal will be likely reached using future datasets such as from Euclid, LSST, and SKA.
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Submitted 20 April, 2018; v1 submitted 9 October, 2017;
originally announced October 2017.