The impact of cosmic filaments on the abundance of satellite galaxies

Abstract

The impact of cosmic web environments on galaxy properties plays a critical role in understanding galaxy formation. Using the state-of-the-art cosmological simulation IllustrisTNG, we investigate how satellite galaxy abundance differs between filaments and the field, with filaments identified using the DisPerSE algorithm. When filaments are identified using galaxies as tracers, we find that, across all magnitude bins, central galaxies in filaments tend to host more satellite galaxies than their counterparts in the field, in qualitative agreement with observational results from the Sloan Digital Sky Survey. The average ratios between satellite luminosity functions in filaments and the field are $3.49$, $2.61$, and $1.90$ in the central galaxy $r$-band magnitude bins of $M_{r,\mathrm{cen}}\sim -22$, $-21$, and $-20$, respectively. We show that much of this excess can be attributed to the higher host halo masses of galaxies in filaments. After resampling central galaxies in both environments to match the halo mass distributions within each magnitude bin, the satellite abundance enhancement in filaments is reduced by up to $79\%$. Additionally, the choice of tracers used to identify filaments introduces a significant bias: when filaments are identified using the dark matter density field, the environmental difference in satellite abundance is reduced by more than $70\%$; after further resampling in both magnitude and halo mass, the difference is further suppressed by another $\sim 60$--$95\%$. Our results highlight the importance of halo mass differences and tracer choice biases when interpreting and understanding the impact of environment on satellite galaxy properties.

19 pages, 10 figures; accepted for publication in ApJ

References in corpus (24)

• Array Programming with NumPy
• Properties of Dark Matter Haloes in Clusters, Filaments, Sheets and Voids
• Dark matter and cosmic structure
• The Evolution of Dark Matter Halo Properties in Clusters, Filaments, Sheets and Voids
• Spin alignment of dark matter haloes in filaments and walls
• Environmental Dependence of Dark Matter Halo Growth I: Halo Merger Rates
• Cosmic Web of Galaxies in the COSMOS Field: Public Catalog and Different Quenching for Centrals and Satellites
• The Cosmic Ballet II: Spin alignment of galaxies and haloes with large-scale filaments in the EAGLE simulation
• The statistics of the subhalo abundance of dark matter haloes
• Characterising filaments in the SDSS volume from the galaxy distribution
• Virgo Filaments I: Processing of gas in cosmological filaments around the Virgo cluster
• Like a spider in its web: a study of the Large Scale Structure around the Coma cluster
• Galaxy properties and the cosmic web in simulations
• A comparison of cosmological filaments catalogues
• The boundary of cosmic filaments
• Galaxy properties in the cosmic web of EAGLE simulation
• The impact of filaments on dwarf galaxy properties in the Auriga simulations
• Prospects for detecting cosmic filaments in Lyman-alpha emission across redshifts $z=2-5$
• On the width and profiles of cosmic filaments
• Galaxy and halo properties around cosmic filaments from Sloan Digital Sky Survey Data Release 7 and the ELUCID simulation
• Impact of cosmic web on the properties of galaxies in IllustrisTNG simulations
• Caught in the cosmic web: environmental effects on subhalo abundance and internal density profiles
• Galaxies in the simulated cosmic web: I. Filament identification and their properties
• The causal effect of cosmic filaments on dark matter halos