KSZ Velocity Reconstruction with ACT and DESI-LS using a Tomographic QML Power Spectrum Estimator

2025/06/26 by Lai, Anderson C. M., Yurii Kvasiuk, Moritz Münchmeyer +2 · 5 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena

paper · pdf · doi:10.48550/arxiv.2506.21684

openalex publication_date 2025/06/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We perform kinetic Sunyaev-Zel'dovich (kSZ) velocity reconstruction on data from ACT DR6 and DESI-LS DR9. To estimate the cross-power between kSZ velocity reconstruction and galaxy density, we make use of a novel quadratic maximum likelihood QML power spectrum estimator implementation in red-shift binned spherical coordinates. We find a detection of the kSZ signal from the cross-correlation between the estimated velocity field and the large-scale galaxy field of 11.7 σ. We estimate an amplitude A=0.39 ± 0.04 of the kSZ signal with respect to a halo model prediction, possibly indicating a high feedback in massive halos, in agreement with previous studies. Our result demonstrates the feasibility of an optimal QML pipeline at the resolution required for this analysis, and will be a powerful tool for kSZ cosmology with upcoming high-resolution surveys.

Cited by

• The kSZ optical depth degeneracy and future constraints on local primordial non-Gaussianity
• QML-FAST - A Fast Code for low-ℓ Tomographic Maximum Likelihood Power Spectrum Estimation
• Probing Dark Energy Microphysics with kSZ Tomography
• Electrons Everywhere, All at Once: A Novel kSZ Estimator for Electron-Electron Correlations
• Reconstruction of Dark Matter and Baryon Density From Galaxies: A Comparison of Linear, Halo Model and Machine Learning-Based Methods

Related

• Velocity Reconstruction from KSZ: Measuring f_NL with ACT and DESILS
• The Atacama Cosmology Telescope: Large-scale velocity reconstruction with the kinematic Sunyaev--Zel'dovich effect and DESI LRGs
• Velocity reconstruction in the era of DESI and Rubin (part II): Realistic samples on the light cone
• The Atacama Cosmology Telescope: Cross-correlation of kSZ and continuity equation velocity reconstruction with photometric DESI LRGs
• Constraints on local primordial non-Gaussianity with 3d Velocity Reconstruction from the Kinetic Sunyaev-Zeldovich Effect