The Intrinsic Alignment of Galaxies and its Impact on Weak Gravitational Lensing in an Era of Precision Cosmology

  title={The Intrinsic Alignment of Galaxies and its Impact on Weak Gravitational Lensing in an Era of Precision Cosmology},
  author={Michael Troxel and Mustapha Ishak},
  journal={arXiv: Cosmology and Nongalactic Astrophysics},
The wealth of incoming and future cosmological observations will allow us to map out the structure and evolution of the observable universe to an unprecedented level of precision. Among these observations is the weak gravitational lensing of galaxies, e.g., cosmic shear that measures the minute distortions of background galaxy images by intervening cosmic structure. Weak lensing and cosmic shear promise to be a powerful probe of astrophysics and cosmology, constraining models of dark energy… 
Cosmology with cosmic shear observations: a review.
  • M. Kilbinger
  • Physics, Medicine
    Reports on progress in physics. Physical Society
  • 2015
An outlook on the various future surveys and missions, for which cosmic shear is one of the main science drivers, and discuss promising new weak cosmological lensing techniques for future observations are discussed.
Galaxy Alignments: Observations and Impact on Cosmology
Galaxy shapes are not randomly oriented, rather they are statistically aligned in a way that can depend on formation environment, history and galaxy type. Studying the alignment of galaxies can
Time evolution of intrinsic alignments of galaxies
Intrinsic alignments (IA), correlations between the intrinsic shapes and orientations of galaxies on the sky, are both a significant systematic in weak lensing and a probe of the effect of
Full-sky ray-tracing simulation of weak lensing using ELUCID simulations: exploring galaxy intrinsic alignment and cosmic shear correlations
The intrinsic alignment of galaxies is an important systematic effect in weak-lensing surveys, which can affect the derived cosmological parameters. One direct way to distinguish different alignment
Angular ellipticity correlations in a composite alignment model for elliptical and spiral galaxies and inference from weak lensing
We investigate a physical, composite alignment model for both spiral and elliptical galaxies and its impact on cosmological parameter estimation from weak lensing for a tomographic survey.
Intrinsic alignment contamination to CMB lensing–galaxy weak lensing correlations from tidal torquing
Correlations of galaxy ellipticities with large-scale structure, due to galactic tidal interactions, provide a potentially significant contaminant to measurements of cosmic shear. However, these
On the origin of intrinsic alignment in cosmic shear measurements: an analytic argument
Galaxy intrinsic alignment can be a severe source of error in weak-lensing studies. The problem has been widely studied by numerical simulations and with heuristic models, but without a clear
The impact of cosmic variance on simulating weak lensing surveys
Upcoming weak lensing surveys will survey large cosmological volumes to measure the growth of cosmological structure with time and thereby constrain dark energy. One major systematic uncertainty in
Intrinsic alignments of galaxies in the Horizon-AGN cosmological hydrodynamical simulation
The intrinsic alignments of galaxies are recognised as a contaminant to weak gravitational lensing measurements. In this work, we study the alignment of galaxy shapes and spins at low redshift
Field-level inference of galaxy intrinsic alignment from the SDSS-III BOSS survey
As a large-scale overdensity collapses, it affects the orientation and shape of galaxies that form, by exerting tidal shear along their axes. Therefore, the shapes of elliptical galaxies align with


Intrinsic alignment of simulated galaxies in the cosmic web: implications for weak lensing surveys
The intrinsic alignment of galaxy shapes and their cross-correlation with the surrounding dark matter tidal field are investigated using the 160 000, z = 1.2 synthetic galaxies extracted from the
Cosmic shear as a tool for precision cosmology: Minimising intrinsic galaxy alignment-lensing interference
Cosmic shear leads to a correlation of the observed ellipticities of galaxies, an effect which is used to place constraints on cosmological parameters, and to explore the evolution of dark matter and
Intrinsic correlation of galaxy shapes: implications for weak lensing measurements
Weak gravitational lensing is now established as a powerful method to measure mass fluctuations in the universe. It relies on the measurement of small coherent distortions of the images of background
Testing the tidal alignment model of galaxy intrinsic alignment
Weak gravitational lensing has become a powerful probe of large-scale structure and cosmological parameters. Precision weak lensing measurements require an understanding of the intrinsic alignment of
Intrinsic alignments in the cross-correlation of cosmic shear and cosmic microwave background weak lensing
We demonstrate that the intrinsic alignment of galaxies with large-scale tidal fields sources an extra contribution to the recently-detected cross-correlation of galaxy shear and weak lensing of the
Detection of weak gravitational lensing distortions of distant galaxies by cosmic dark matter at large scales
The detection of cosmic shear on angular scales of up to half a degree is reported using 145,000 galaxies and along three separate lines of sight and it is found that the dark matter is distributed in a manner consistent with either an open universe, or a flat universe that is dominated by a cosmological constant.
Intrinsic alignment-lensing interference as a contaminant of cosmic shear
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
A halo model for intrinsic alignments of galaxy ellipticities
Correlations between intrinsic ellipticities of galaxies are a potentially important systematic error when constraining dark energy properties from weak gravitational lensing (cosmic shear) surveys.
The influence of galaxy formation physics on weak lensing tests of general relativity
Forthcoming projects such as the Dark Energy Survey, Joint Dark Energy Mission, and the Large Synoptic Survey Telescope, aim to measure weak lensing shear correlations with unprecedented accuracy.
Intrinsic galaxy shapes and alignments – II. Modelling the intrinsic alignment contamination of weak lensing surveys
Intrinsic galaxy alignments constitute the major astrophysical systematic of forthcoming weak gravitational lensing surveys but also yield unique insights into galaxy formation and evolution. We