Service interruption on Monday 11 July from 12:30 to 13:00: all the sites of the CCSD (HAL, EpiSciences, SciencesConf, AureHAL) will be inaccessible (network hardware connection).
Skip to Main content Skip to Navigation
Journal articles

Intrinsic alignments of galaxies in the Horizon-AGN cosmological hydrodynamical simulation

Abstract : The intrinsic alignments of galaxies are recognized as a contaminant to weak gravitational lensing measurements. In this work, we study the alignment of galaxy shapes and spins at low redshift (z ∼ 0.5) in Horizon-AGN, an adaptive-mesh-refinement hydrodynamical cosmological simulation box of 100 h- 1 Mpc a side with AGN feedback implementation. We find that spheroidal galaxies in the simulation show a tendency to be aligned radially towards overdensities in the dark matter density field and other spheroidals. This trend is in agreement with observations, but the amplitude of the signal depends strongly on how shapes are measured and how galaxies are selected in the simulation. Disc galaxies show a tendency to be oriented tangentially around spheroidals in three dimensions. While this signal seems suppressed in projection, this does not guarantee that disc alignments can be safely ignored in future weak lensing surveys. The shape alignments of luminous galaxies in Horizon-AGN are in agreement with observations and other simulation works, but we find less alignment for lower luminosity populations. We also characterize the systematics of galaxy shapes in the simulation and show that they can be safely neglected when measuring the correlation of the density field and galaxy ellipticities.
Complete list of metadata

https://hal-insu.archives-ouvertes.fr/insu-03644671
Contributor : Hal Sorbonne Université Gestionnaire Connect in order to contact the contributor
Submitted on : Monday, April 25, 2022 - 11:00:35 AM
Last modification on : Thursday, May 12, 2022 - 6:22:03 PM

File

stv2154.pdf
Publisher files allowed on an open archive

Identifiers

Citation

N. Chisari, S. Codis, C. Laigle, y. Dubois, C. Pichon, et al.. Intrinsic alignments of galaxies in the Horizon-AGN cosmological hydrodynamical simulation. Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P - Oxford Open Option A, 2015, 454, pp.2736-2753. ⟨10.1093/mnras/stv2154⟩. ⟨insu-03644671⟩

Share

Metrics

Record views

15

Files downloads

2