{"title":"A rising tide: intrinsic alignments since the turn of the millennium","authors":"Nora Elisa Chisari","doi":"10.1007/s00159-025-00161-8","DOIUrl":null,"url":null,"abstract":"<div><p>The alignments of galaxies across the large-scale structure of the Universe are known to be a source of contamination for gravitational lensing, but they can also probe cosmology and the physics of galaxy evolution in many ways. In this review, I cover developments in our understanding of intrinsic alignments over the past 25 years on: (1) different approaches to model intrinsic alignments across a range of scales, (2) existing observational constraints, (3) predictions from cosmological numerical <i>N</i>-body and hydrodynamical simulations, (4) mitigation strategies to account for their contamination to lensing observables and (5) cosmological and astrophysical applications. While the review focuses mostly on two-point statistics of intrinsic alignments, I also give a summary of other statistics beyond two-point. Finally, I point out some of the open problems hindering the understanding or application of intrinsic alignments and how they might be overcome in the future.</p></div>","PeriodicalId":785,"journal":{"name":"The Astronomy and Astrophysics Review","volume":"33 1","pages":""},"PeriodicalIF":26.5000,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00159-025-00161-8.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Astronomy and Astrophysics Review","FirstCategoryId":"4","ListUrlMain":"https://link.springer.com/article/10.1007/s00159-025-00161-8","RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
The alignments of galaxies across the large-scale structure of the Universe are known to be a source of contamination for gravitational lensing, but they can also probe cosmology and the physics of galaxy evolution in many ways. In this review, I cover developments in our understanding of intrinsic alignments over the past 25 years on: (1) different approaches to model intrinsic alignments across a range of scales, (2) existing observational constraints, (3) predictions from cosmological numerical N-body and hydrodynamical simulations, (4) mitigation strategies to account for their contamination to lensing observables and (5) cosmological and astrophysical applications. While the review focuses mostly on two-point statistics of intrinsic alignments, I also give a summary of other statistics beyond two-point. Finally, I point out some of the open problems hindering the understanding or application of intrinsic alignments and how they might be overcome in the future.
期刊介绍:
The Astronomy and Astrophysics Review is a journal that covers all areas of astronomy and astrophysics. It includes subjects related to other fields such as laboratory or particle physics, cosmic ray physics, studies in the solar system, astrobiology, instrumentation, and computational and statistical methods with specific astronomical applications. The frequency of review articles depends on the level of activity in different areas. The journal focuses on publishing review articles that are scientifically rigorous and easily comprehensible. These articles serve as a valuable resource for scientists, students, researchers, and lecturers who want to explore new or unfamiliar fields. The journal is abstracted and indexed in various databases including the Astrophysics Data System (ADS), BFI List, CNKI, CNPIEC, Current Contents/Physical, Chemical and Earth Sciences, Dimensions, EBSCO Academic Search, EI Compendex, Japanese Science and Technology, and more.