Skip to main content

Research Repository

Advanced Search

The MillenniumTNG Project: Intrinsic alignments of galaxies and halos

Delgado, Ana Maria; Hadzhiyska, Boryana; Bose, Sownak; Springel, Volker; Hernquist, Lars; Barrera, Monica; Pakmor, Rüdiger; Ferlito, Fulvio; Kannan, Rahul; Hernández-Aguayo, César; White, Simon DM; Frenk, Carlos

The MillenniumTNG Project: Intrinsic alignments of galaxies and halos Thumbnail


Ana Maria Delgado

Boryana Hadzhiyska

Volker Springel

Lars Hernquist

Monica Barrera

Rüdiger Pakmor

Fulvio Ferlito

Rahul Kannan

César Hernández-Aguayo

Simon DM White


The intrinsic alignment (IA) of observed galaxy shapes with the underlying cosmic web is a source of contamination in weak lensing surveys. Sensitive methods to identify the IA signal will therefore need to be included in the upcoming weak lensing analysis pipelines. Hydrodynamical cosmological simulations allow us to directly measure the intrinsic ellipticities of galaxies and thus provide a powerful approach to predict and understand the IA signal. Here we employ the novel, large-volume hydrodynamical simulation MTNG740, a product of the MillenniumTNG (MTNG) project, to study the IA of galaxies. We measure the projected correlation functions between the intrinsic shape/shear of galaxies and various tracers of large-scale structure, w+g, w+m, w++ over the radial range rp ∈ [0.02, 200] h−1Mpc and at redshifts z = 0.0, 0.5 and 1.0. We detect significant signal-to-noise IA signals with the density field for both elliptical and spiral galaxies. We also find significant intrinsic shear-shear correlations for ellipticals. We further examine correlations of the intrinsic shape of galaxies with the local tidal field. Here we find a significant IA signal for elliptical galaxies assuming a linear model. We also detect a weak IA signal for spiral galaxies under a quadratic tidal torquing model. Lastly, we measure the alignment between central galaxies and their host dark-matter halos, finding small to moderate misalignments between their principal axes that decline with halo mass.


Delgado, A. M., Hadzhiyska, B., Bose, S., Springel, V., Hernquist, L., Barrera, M., …Frenk, C. (2023). The MillenniumTNG Project: Intrinsic alignments of galaxies and halos. Monthly Notices of the Royal Astronomical Society, 523(4), 5899–5914.

Journal Article Type Article
Acceptance Date Apr 24, 2023
Online Publication Date Jun 16, 2023
Publication Date Aug 4, 2023
Deposit Date Jun 23, 2023
Publicly Available Date Jun 23, 2023
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Royal Astronomical Society
Peer Reviewed Peer Reviewed
Volume 523
Issue 4
Pages 5899–5914
Public URL
Related Public URLs


Accepted Journal Article (4.2 Mb)

Copyright Statement
This is a pre-copyedited, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The version of record is available online at:

You might also like

Downloadable Citations