Model-Independent Measurement of Baryon Gas Fractions through Galaxy-Galaxy Lensing and the Kinematic Sunyaev-Zel'dovich Effect

@misc{liu2026modelindependent,
  title = {{Model-Independent Measurement of Baryon Gas Fractions through Galaxy-Galaxy Lensing and the Kinematic Sunyaev-Zel'dovich Effect}},
  author = {R. Henry Liu and Uroš Seljak and Simone Ferraro and Boryana Hadzhiyska and Frank J Qu and Bernardita Ried Guachalla and Emmanuel Schaan and Jessica Nicole Aguilar and Steven Ahlen and Anton Baleato Lizancos and Florian Beutler and Davide Bianchi and David Brooks and Aurelio Carnero Rosell and Francisco Javier Castander and Todd Claybaugh and Andrei Cuceu and Axel de la Macorra and Jaime E Forero-Romero and Enrique Gaztañaga and Satya Gontcho A. Gontcho and Gaston Gutierrez and Klaus Honscheid and Dragan Huterer and Mustapha Ishak and Stephanie Juneau and Tanveer Karim and David Kirkby and Anthony Kremin and Ofer Lahav and Martin Landriau and Laurent Le Guillou and Martine Lokken and Marc Manera and Aaron Meisner and Ramon Miquel and John Moustakas and Seshadri Nadathur and Jeffrey A Newman and Hernan Enrique Noriega and Will Percival and Ignasi Pérez-Ràfols and Francisco Prada and Corentin Ravoux and Graziano Rossi and Lado Samushia and Eusebio Sanchez and Christoph Saulder and David Schlegel and Michael Schubnell and Hee-Jong Seo and Małgorzata Siudek and Gregory Tarlé and Benjamin Alan Weaver and Rongpu Zhou},
  howpublished = {HAL},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.22466},
  eprint = {2609.22466},
  archivePrefix = {arXiv},
  url = {https://hal.science/hal-05763150v1},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - Model-Independent Measurement of Baryon Gas Fractions through Galaxy-Galaxy Lensing and the Kinematic Sunyaev-Zel'dovich Effect
AU  - R. Henry Liu
AU  - Uroš Seljak
AU  - Simone Ferraro
AU  - Boryana Hadzhiyska
AU  - Frank J Qu
AU  - Bernardita Ried Guachalla
AU  - Emmanuel Schaan
AU  - Jessica Nicole Aguilar
AU  - Steven Ahlen
AU  - Anton Baleato Lizancos
AU  - Florian Beutler
AU  - Davide Bianchi
AU  - David Brooks
AU  - Aurelio Carnero Rosell
AU  - Francisco Javier Castander
AU  - Todd Claybaugh
AU  - Andrei Cuceu
AU  - Axel de la Macorra
AU  - Jaime E Forero-Romero
AU  - Enrique Gaztañaga
AU  - Satya Gontcho A. Gontcho
AU  - Gaston Gutierrez
AU  - Klaus Honscheid
AU  - Dragan Huterer
AU  - Mustapha Ishak
AU  - Stephanie Juneau
AU  - Tanveer Karim
AU  - David Kirkby
AU  - Anthony Kremin
AU  - Ofer Lahav
AU  - Martin Landriau
AU  - Laurent Le Guillou
AU  - Martine Lokken
AU  - Marc Manera
AU  - Aaron Meisner
AU  - Ramon Miquel
AU  - John Moustakas
AU  - Seshadri Nadathur
AU  - Jeffrey A Newman
AU  - Hernan Enrique Noriega
AU  - Will Percival
AU  - Ignasi Pérez-Ràfols
AU  - Francisco Prada
AU  - Corentin Ravoux
AU  - Graziano Rossi
AU  - Lado Samushia
AU  - Eusebio Sanchez
AU  - Christoph Saulder
AU  - David Schlegel
AU  - Michael Schubnell
AU  - Hee-Jong Seo
AU  - Małgorzata Siudek
AU  - Gregory Tarlé
AU  - Benjamin Alan Weaver
AU  - Rongpu Zhou
PY  - 2026
DA  - 2026/09/24
PB  - HAL
DO  - 10.48550/arxiv.2609.22466
UR  - https://hal.science/hal-05763150v1
AB  - Baryon feedback is a leading source of systematic uncertainty for cosmology from weak lensing, but measurements of the gas distribution around galaxies have largely relied on parametric profile models or simulation-calibrated frameworks. We present model independent measurements of the radial gas fraction profile around galaxies, combining galaxy-galaxy lensing and kinematic Sunyaev-Zel'dovich (kSZ) effect. We introduce a method that applies the same radial ΔΣ aperture filter to both the galaxy-galaxy lensing shear field and the velocity-weighted kSZ temperature maps; their ratio directly yields ΔΣ filtered gas fraction f_gas(R), the ratio of ionized gas to total matter as a function of projected radius. We apply this approach to DESI DR2 Bright Galaxy Survey (BGS, z̅ ≈ 0.26) and Luminous Red Galaxy (LRG, 0.4 < z < 1.1) samples, using ACT DR6 component-separated CMB maps for kSZ, and the HSC Year 3 shear catalog for weak lensing. After correcting for ACT beam suppression using a simulation-calibrated compensation factor, we detect baryon depletion relative to the cosmic mean baryon fraction at SNR = 17.2 (BGS) and SNR = 13.8 (LRG bin 1). Comparison with six hydrodynamical simulations from the Illustris, IllustrisTNG, SIMBA, and FLAMINGO suites shows that the fiducial FLAMINGO run most closely tracks the observed radial gas distribution in both samples, with Illustris-1 and TNG300-1 bracketing the data from below and above at small radii. We find a mild discrepancy between the kSZ measurements in the South and North Galactic Caps in one LRG redshift bin, which may indicate residual systematics. We show that the ratio is robust to splits by stellar mass and to the removal of close pairs. These results establish ΔΣ filtering of kSZ versus weak lensing signal as a model-independent probe of the baryon distribution around galaxies.
ER  -