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Related papers: Modeling Intrinsic Galaxy Alignment in the MICE Si…

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The statistical properties of the ellipticities of galaxy images depend on how galaxies form and evolve, and therefore constrain models of galaxy morphology, which are key to the removal of the intrinsic alignment contamination of…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-28 B. Joachimi , E. Semboloni , P. E. Bett , J. Hartlap , S. Hilbert , H. Hoekstra , P. Schneider , T. Schrabback

We present DELTA (Data-Empiric Learned Tidal Alignments), a deep learning model that isolates galaxy intrinsic alignments (IAs) from weak lensing distortions using only observational data. The model uses an Equivariant Graph Neural Network…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-11 Matthew Craigie , Eric Huff , Yuan-Sen Ting , Rossana Ruggeri , Tamara M. Davis

The intrinsic alignment of galaxies with the large-scale density field is an important astrophysical contaminant in upcoming weak lensing surveys. We present detailed measurements of the galaxy intrinsic alignments and associated…

Cosmology and Nongalactic Astrophysics · Physics 2015-02-12 Ananth Tenneti , Sukhdeep Singh , Rachel Mandelbaum , Tiziana Di Matteo , Yu Feng , Nishikanta Khandai

Intrinsic alignments are a major astrophysical contaminant for next generation large-sky surveys like Euclid and LSST. Large hydrodynamic simulations are crucial for informing the alignment modelling for these surveys. We measure…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-23 A. Herle , N. E. Chisari , H. Hoekstra , D. Navarro-Gironés , M. Schaller , J. Schaye

We measure the alignment of the shapes of galaxy clusters, as traced by their satellite distributions, with the matter density field using the public redMaPPer catalogue based on SDSS-DR8, which contains 26 111 clusters up to z~0.6. The…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-31 Edo van Uitert , Benjamin Joachimi

We summarize common notations and concepts in the field of Intrinsic Alignments (IA). IA refers to physical correlations involving galaxy shapes, galaxy spins, and the underlying cosmic web. Its characterization is an important aspect of…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-27 Claire Lamman , Eleni Tsaprazi , Jingjing Shi , Nikolina Niko Šarčević , Susan Pyne , Elisa Legnani , Tassia Ferreira

Forthcoming cosmological imaging surveys, such as the Rubin Observatory LSST, require large-scale simulations encompassing realistic galaxy populations for a variety of scientific applications. Of particular concern is the phenomenon of…

Astrophysics of Galaxies · Physics 2024-09-30 Yesukhei Jagvaral , Francois Lanusse , Rachel Mandelbaum

Gravitational lensing causes background galaxy images to become aligned, and the statistical characteristics of the image alignments can then be used to constrain the power spectrum of mass fluctuations. Analyses of gravitational lensing…

Astrophysics · Physics 2017-08-23 A. F. Heavens

We use the IllustrisTNG suite of cosmological simulations to measure intrinsic alignment (IA) bispectra of dark matter subhalos between redshifts 0 and 1. We decompose the intrinsic shear field into E- and B-modes and find that the…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-12 Susan Pyne , Ananth Tenneti , Benjamin Joachimi

We present predictions for the galaxy-galaxy lensing profile from the EAGLE hydrodynamical cosmological simulation at redshift z=0.18, in the spatial range 0.02 < R/(Mpc/h) < 2, and for five logarithmically equi-spaced stellar mass bins in…

We consider the effect of galaxy intrinsic alignments (IAs) on dark energy constraints from weak gravitational lensing. We summarise the latest version of the linear alignment model of IAs, following the brief note of Hirata & Seljak (2010)…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Donnacha Kirk , Anais Rassat , Ole Host , Sarah Bridle

Investigating intrinsic alignments (IAs) of galaxy shapes is important not only to constrain cosmological parameters unbiasedly from gravitational lensing but also to extract cosmological information complimentary to galaxy clustering…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-26 Teppei Okumura , Atsushi Taruya

Intrinsic alignments (IA) of galaxies have been recognized as one of the most serious contaminants to weak lensing. These systematics need to be isolated and mitigated in order for ongoing and future lensing surveys to reach their full…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-15 Ji Yao , Mustapha Ishak , Weikang Lin , M. A. Troxel

Cosmic shear surveys have great promise as tools for precision cosmology, but can be subject to systematic errors including intrinsic ellipticity correlations of the source galaxies. The intrinsic alignments are believed to be small for…

Astrophysics · Physics 2010-10-28 Christopher M. Hirata , Uros Seljak

Tidal gravitational forces can modify the shape of galaxies and clusters of galaxies, thus correlating their orientation with the surrounding matter density field. We study the dependence of this phenomenon, known as intrinsic alignment…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-06 Davide Piras , Benjamin Joachimi , Björn Malte Schäfer , Mario Bonamigo , Stefan Hilbert , Edo van Uitert

Emission line galaxies (ELGs), more generally star-forming galaxies, are valuable tracers of large-scale structure and therefore main targets of upcoming wide-area spectroscopic galaxy surveys. We propose a fixed-aperture shape estimator of…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-08 Jingjing Shi , Ken Osato , Toshiki Kurita , Masahiro Takada

The intrinsic alignment of galaxy shapes with the large-scale density field is a contaminant to weak lensing measurements, as well as being an interesting signature of galaxy formation and evolution (albeit one that is difficult to predict…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-29 Ananth Tenneti , Rachel Mandelbaum , Tiziana Di Matteo , Yu Feng , Nishikanta Khandai

Intrinsic alignment (IA) of source galaxies represents an important contaminant for upcoming cosmic shear surveys. In particular, it is expected on general grounds that IA contains a B-mode while the weak lensing signal does not. Thus, a…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-13 Christos Georgiou , Thomas Bakx , Juliard van Donkersgoed , Nora Elisa Chisari

There is a growing interest of using the intrinsic alignment (IA) of galaxy images as a tool to extract cosmological information complimentary to galaxy clustering analysis. Recently, Okumura & Taruya derived useful formulas for the…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-07 Teppei Okumura , Atsushi Taruya , Takahiro Nishimichi

Many galaxy formation models predict alignments between galaxy spin and the cosmic web (i.e. the directions of filaments and sheets), leading to intrinsic alignment between galaxies that creates a systematic error in weak lensing…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-08 Alex Krolewski , Khee-Gan Lee , Zarija Lukic , Martin White