Intrinsic correlations of galaxy sizes in a hydrodynamical cosmological simulation

Abstract

Residuals between measured galactic radii and those predicted by the Fundamental Plane (FP) are possible tracers of weak lensing magnification. However, observations have shown these to be systematically correlated with the large-scale structure. We use the Horizon-AGN hydrodynamical cosmological simulation to analyse these intrinsic size correlations (ISCs) for both elliptical (early-type) and spiral (late-type) galaxies at $z=0.06$. We fit separate FPs to each sample, finding similarly distributed radius residuals, $\lambda$, in each case. We find persistent $\lambda \lambda$ correlations over three-dimensional separations $0.5-17h^{-1}\mathrm{Mpc}$ in the case of spiral galaxies, at $>3\sigma$ significance. When relaxing a mass-selection, applied for better agreement with galaxy clustering constraints, the spiral $\lambda \lambda$ detection strengthens to $9\sigma$; we detect a $5\sigma$ density-$\lambda$ correlation; and we observe intrinsically-large spirals to cluster more strongly than small spirals over scales $\lesssim 10h^{-1}\mathrm{Mpc}$, at $>5\sigma$ significance. Conversely, and in agreement with the literature, we observe lower-mass, intrinsically-small ellipticals to cluster more strongly than their large counterparts over scales $0.5-17h^{-1}\mathrm{Mpc}$, at $>5\sigma$ significance. We model $\lambda \lambda$ correlations using a phenomenological non-linear size model, and predict the level of contamination for cosmic convergence analyses. We find the systematic contribution to be of similar order to, or dominant over the cosmological signal. We make a mock measurement of an intrinsic, systematic contribution to the projected surface mass density $\Sigma (r)$ and find statistically significant, low-amplitude, positive (negative) contributions from lower-mass spirals (ellipticals), which may be of concern for large-scale ($\gtrsim 7h^{-1}$ Mpc) measurements.

26 pages, 11 figures, matches MNRAS accepted version

References in corpus (29)

• The 2.5 m Telescope of the Sloan Digital Sky Survey
• 3D-HST+CANDELS: The Evolution of the Galaxy Size-Mass Distribution since $z=3$
• Why your model parameter confidences might be too optimistic -- unbiased estimation of the inverse covariance matrix
• Forming Disk Galaxies in Lambda CDM Simulations
• Density profiles of galaxy groups and clusters from SDSS galaxy-galaxy weak lensing
• Half-mass radii for ~7,000 galaxies at 1.0 < z < 2.5: most of the evolution in the mass-size relation is due to color gradients
• Joint analysis of 6dFGS and SDSS peculiar velocities for the growth rate of cosmic structure and tests of gravity
• The Cosmic Ballet II: Spin alignment of galaxies and haloes with large-scale filaments in the EAGLE simulation
• Extending the evolution of the stellar mass-size relation at $z\le 2$ to low stellar mass galaxies from HFF and CANDELS
• Mergers drive spin swings along the cosmic web
• An EFT description of galaxy intrinsic alignments
• Hyper Suprime-Cam Subaru Strategic Program: A Mass-Dependent Slope of the Galaxy Size-Mass Relation at $z<1$
• Galaxy And Mass Assembly (GAMA): The galaxy luminosity function within the cosmic web
• Half-mass radii of quiescent and star-forming galaxies evolve slowly from 0 < z < 2.5: implications for galaxy assembly histories
• The Fundamental Plane of Early Type Galaxies in Nearby Clusters from the WINGS Database
• The effect of the environment on the stellar mass - size relation of present-day galaxies
• Lensing Bias in Cosmic Shear
• HST/WFC3 grism observations of $z\sim 1$ clusters: The cluster vs. field stellar mass-size relation and evidence for size growth of quiescent galaxies from minor mergers
• SDSS-IV MaNGA: 3D spin alignment of spiral and S0 galaxies
• A tight angular-momentum plane for disc galaxies
• On cosmological bias due to the magnification of shear and position samples in modern weak lensing analyses
• Cosmology from Clustering, Cosmic Shear, CMB Lensing, and Cross Correlations: Combining Rubin Observatory and Simons Observatory
• The Fundamental Plane Relation of Early-Type Galaxies: Environmental Dependence
• Tightening weak lensing constraints on the ellipticity of galaxy-scale dark matter haloes
• Detection of the Mass-Dependent Dual-Type Transition of Galaxy Spins in IllustrisTNG Simulations
• Comparing Galaxy Clustering in Horizon-AGN Simulated Lightcone Mocks and VIDEO Observations
• Intrinsic size correlations in weak lensing
• Modelling the impact of intrinsic size and luminosity correlations on magnification estimation
• Forecasting the potential of weak lensing magnification to enhance LSST large-scale structure analyses

Cited by in corpus (3)

• Catalog-based pseudo-$C_{\ell }$s
• A rising tide: Intrinsic alignments since the turn of the millennium
• Astrophysical systematics in Kinematic Lensing: quantifying an Intrinsic Alignment analog