---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '21724'
abstract:
- lang: eng
  text: 'The next generation of weak-gravitational-lensing surveys has the potential
    to place stringent constraints on cosmological parameters. However, their analysis
    is limited by systematics such as the intrinsic alignments of galaxies, which
    alter weak-lensing convergence and can lead to biases in cosmological parameter
    estimations. For the first time, in this work, we investigate the impact of intrinsic
    alignments on non-Gaussian statistics of the weak-lensing field using galaxy shapes
    derived from the IllustrisTNG hydrodynamical simulation. We create two catalogs
    of ray-traced convergence maps: one that includes the measured intrinsic shape
    of each galaxy and another where all galaxies are randomly rotated to eliminate
    intrinsic alignments. We compare a range of weak-lensing statistics between the
    two catalogs, including the shear–shear correlation function, the map-level angular
    power spectrum, one-point, peak count, and minimum distribution functions, and
    Minkowski functionals. For each statistic, we assess the level of statistical
    distinguishability between catalogs for a set of future survey angular areas.
    Our results reveal strong small-scale correlation in the alignment of galaxies
    and statistically significant boosts in weak-lensing convergence in both positive
    and negative directions for high-significance peaks and minima, respectively.
    We note that our analysis is at a fixed number density of  ˜ 5 arcmin^-2, drawn
    from a single realization of initial conditions, and does not include observational
    uncertainties or supersample covariance contributions. Weak-lensing analyses utilizing
    non-Gaussian statistics must account for intrinsic alignments to avoid significantly
    compromised cosmological inferences.'
acknowledgement: We thank Fulvio Ferlito, Ana Maria Delgado, and Ken Osato for helpful
  conversations during this work. M.E.L. is supported by NSF grant DGE-2036197. Z.H.
  acknowledges financial support from NASA ATP grant 80NSSC24K1093. The Flatiron Institute
  is supported by the Simons Foundation.
article_number: '36'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Max E.
  full_name: Lee, Max E.
  last_name: Lee
- first_name: Zoltán
  full_name: Haiman, Zoltán
  id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36
  last_name: Haiman
  orcid: 0000-0003-3633-5403
- first_name: Shivam
  full_name: Pandey, Shivam
  last_name: Pandey
- first_name: Shy
  full_name: Genel, Shy
  last_name: Genel
citation:
  ama: Lee ME, Haiman Z, Pandey S, Genel S. The effect of intrinsic alignments on
    weak-lensing statistics in hydrodynamical simulations. <i>The Astrophysical Journal</i>.
    2025;996(1). doi:<a href="https://doi.org/10.3847/1538-4357/ae1ca7">10.3847/1538-4357/ae1ca7</a>
  apa: Lee, M. E., Haiman, Z., Pandey, S., &#38; Genel, S. (2025). The effect of intrinsic
    alignments on weak-lensing statistics in hydrodynamical simulations. <i>The Astrophysical
    Journal</i>. IOP Publishing. <a href="https://doi.org/10.3847/1538-4357/ae1ca7">https://doi.org/10.3847/1538-4357/ae1ca7</a>
  chicago: Lee, Max E., Zoltán Haiman, Shivam Pandey, and Shy Genel. “The Effect of
    Intrinsic Alignments on Weak-Lensing Statistics in Hydrodynamical Simulations.”
    <i>The Astrophysical Journal</i>. IOP Publishing, 2025. <a href="https://doi.org/10.3847/1538-4357/ae1ca7">https://doi.org/10.3847/1538-4357/ae1ca7</a>.
  ieee: M. E. Lee, Z. Haiman, S. Pandey, and S. Genel, “The effect of intrinsic alignments
    on weak-lensing statistics in hydrodynamical simulations,” <i>The Astrophysical
    Journal</i>, vol. 996, no. 1. IOP Publishing, 2025.
  ista: Lee ME, Haiman Z, Pandey S, Genel S. 2025. The effect of intrinsic alignments
    on weak-lensing statistics in hydrodynamical simulations. The Astrophysical Journal.
    996(1), 36.
  mla: Lee, Max E., et al. “The Effect of Intrinsic Alignments on Weak-Lensing Statistics
    in Hydrodynamical Simulations.” <i>The Astrophysical Journal</i>, vol. 996, no.
    1, 36, IOP Publishing, 2025, doi:<a href="https://doi.org/10.3847/1538-4357/ae1ca7">10.3847/1538-4357/ae1ca7</a>.
  short: M.E. Lee, Z. Haiman, S. Pandey, S. Genel, The Astrophysical Journal 996 (2025).
date_created: 2026-04-12T22:01:52Z
date_published: 2025-12-23T00:00:00Z
date_updated: 2026-04-13T08:30:52Z
day: '23'
ddc:
- '520'
department:
- _id: ZoHa
doi: 10.3847/1538-4357/ae1ca7
external_id:
  arxiv:
  - '2504.12460'
file:
- access_level: open_access
  checksum: 0d8fa05617420230eac39944b36839e9
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  creator: dernst
  date_created: 2026-04-13T08:20:16Z
  date_updated: 2026-04-13T08:20:16Z
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has_accepted_license: '1'
intvolume: '       996'
issue: '1'
language:
- iso: eng
month: '12'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
  eissn:
  - 1538-4357
  issn:
  - 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: The effect of intrinsic alignments on weak-lensing statistics in hydrodynamical
  simulations
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 996
year: '2025'
...