Galaxy bias and primordial non-Gaussianity: insights from galaxy formation simulations with IllustrisTNG

Abstract

We study the impact that large-scale perturbations of (i) the matter density and (ii) the primordial gravitational potential with local primordial non-Gaussianity (PNG) have on galaxy formation using the IllustrisTNG model. We focus on the linear galaxy bias $b_1$ and the coefficient $b_{\varphi }$ of the scale-dependent bias induced by PNG, which describe the response of galaxy number counts to these two types of perturbations, respectively. We perform our study using separate universe simulations, in which the effect of the perturbations is mimicked by changes to the cosmological parameters: modified cosmic matter density for $b_1$ and modified amplitude ${\mathcal{A}}_s$ of the primordial scalar power spectrum for $b_{\varphi }$. We find that the widely used universality relation $b_{\varphi }=2{\delta }_c(b_1-1)$ is a poor description of the bias of haloes and galaxies selected by stellar mass $M_{\ast }$, which is instead described better by $b_{\varphi }(M_{\ast })=2{\delta }_c(b_1(M_{\ast })-p)$ with $p\in [0.4,0.7]$. This is explained by the different impact that matter overdensities and local PNG have on the median stellar-to-halo-mass relation. A simple model of this impact allows us to describe the stellar mass dependence of $b_1$ and $b_{\varphi }$ fairly well. Our results also show a nontrivial relation between $b_1$ and $b_{\varphi }$ for galaxies selected by color and black hole mass accretion rate. Our results provide refined priors on $b_{\varphi }$ for local PNG constraints and forecasts using galaxy clustering. Given that the widely used universality relation underpredicts $b_{\varphi }(M_{\ast })$, existing analyses may underestimate the true constraining power on local PNG.

21 pages, 12 figures, 1 table. Comments welcomed! v2: version published in JCAP

References in corpus (18)

• The EAGLE project: Simulating the evolution and assembly of galaxies and their environments
• Introducing the Illustris Project: Simulating the coevolution of dark and visible matter in the Universe
• Simulating galaxy formation with black hole driven thermal and kinetic feedback
• Introducing the Illustris Project: the evolution of galaxy populations across cosmic time
• The imprints of primordial non-gaussianities on large-scale structure: scale dependent bias and abundance of virialized objects
• Clustering of dark matter tracers: generalizing bias for the coming era of precision LSS
• Gravity and Large-Scale Non-local Bias
• The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: cosmological implications of the configuration-space clustering wedges
• Primordial non-gaussianity, statistics of collapsed objects, and the Integrated Sachs-Wolfe effect
• Understanding higher-order nonlocal halo bias at large scales by combining the power spectrum with the bispectrum
• Primordial non-Gaussianity: large-scale structure signature in the perturbative bias model
• The recycling of gas and metals in galaxy formation: predictions of a dynamical feedback model
• Separate Universe Simulations
• Constraints on primordial non-Gaussianity from 800,000 photometric quasars
• Super-Sample Signal
• Non-Gaussian halo assembly bias
• Probing primordial non-Gaussianity via iSW measurements with SKA continuum surveys
• Compensated Isocurvature Perturbations in the Galaxy Power Spectrum

Cited by in corpus (39)

• The CAMELS project: Cosmology and Astrophysics with MachinE Learning Simulations
• Large-scale dark matter simulations
• Constraints on Multi-Field Inflation from the BOSS Galaxy Survey
• Primordial Non-Gaussianity from Biased Tracers: Likelihood Analysis of Real-Space Power Spectrum and Bispectrum
• Can we actually constrain $f_{\mathrm{NL}}$ using the scale-dependent bias effect? An illustration of the impact of galaxy bias uncertainties using the BOSS DR12 galaxy power spectrum
• Galaxy bias from forward models: linear and second-order bias of IllustrisTNG galaxies
• Predictions for local PNG bias in the galaxy power spectrum and bispectrum and the consequences for $f_{\mathrm{NL}}$ constraints
• Bayesian field-level inference of primordial non-Gaussianity using next-generation galaxy surveys
• Assembly bias in the local PNG halo bias and its implication for $f_{\mathrm{NL}}$ constraints
• Learning to Concentrate: Multi-tracer Forecasts on Local Primordial Non-Gaussianity with Machine-Learned Bias
• Local primordial non-Gaussianity from the large-scale clustering of photometric DESI luminous red galaxies
• Constraints on anisotropic primordial non-Gaussianity from intrinsic alignments of SDSS-III BOSS galaxies
• Responses of Halo Occupation Distributions: a new ingredient in the halo model & the impact on galaxy bias
• Modeling HI at the field level
• Local primordial non-Gaussianity in the relativistic galaxy bispectrum
• Light Fields during Inflation from BOSS and Future Galaxy Surveys
• Taming assembly bias for primordial non-Gaussianity
• PNG-UNITsims: Halo clustering response to primordial non-Gaussianities as a function of mass
• Constraining primordial non-Gaussianity by combining next-generation galaxy and 21 cm intensity mapping surveys
• The local PNG bias of neutral Hydrogen, ${\mathrm{H}}_{\mathrm{I}}$
• Ultra-large-scale approximations and galaxy clustering: debiasing constraints on cosmological parameters
• Super-sample covariance of the power spectrum, bispectrum, halos, voids, and their cross covariances
• Halo assembly bias from a deep learning model of halo formation
• The Renormalization Group for Large-Scale Structure: Primordial non-Gaussianities
• Validating galaxy clustering models with Fixed & Paired and Matched-ICs simulations: application to Primordial Non-Gaussianities
• Radio-optical synergies at high redshift to constrain primordial non-Gaussianity
• Bispectrum constraints on Primordial non-Gaussianities with the eBOSS DR16 quasars
• Non-Gaussian assembly bias from a semi-analytic galaxy formation model
• Constraining primordial non-Gaussianity by combining photometric galaxy and 21cm intensity mapping surveys
• Fast and accurate collapse-time predictions for collisionless matter
• How do uncertainties in galaxy formation physics impact field-level galaxy bias?
• Modeling spatially-resolved galactic H$\alpha$ emission for galaxy clustering
• Position-dependent Voronoi probability distribution functions for matter and halos
• Constraints on primordial non-Gaussianity from Quaia
• Multi-tracing the primordial Universe with future surveys
• Linear Relativistic Corrections in the Spherical Fourier-Bessel Power Spectrum
• Parity Violation in Galaxy Shapes: Primordial Non-Gaussianity
• Multi-wavelength spectroscopic probes: prospects for primordial non-Gaussianity and relativistic effects
• A revisited Correction to the Halo Mass Function for local-type Primordial non-Gaussianity