Cosmic Web of Galaxies in the COSMOS Field: Public Catalog and Different Quenching for Centrals and Satellites

Abstract

We use a mass complete (log(  M M )  9.6) sample of galaxies with accurate photometric redshifts in the COSMOS field to construct the density field and the cosmic web to z=1.2. The comic web extraction relies on the density field Hessian matrix and breaks the density field into clusters, filaments, and the field. We provide the density field and cosmic web measures to the community. We show that at z0.8, the median star formation rate (SFR) in the cosmic web gradually declines from the field to clusters and this decline is especially sharp for satellites (∼1 dex versus ∼0.5 dex for centrals). However, at z0.8, the trend flattens out for the overall galaxy population and satellites. For star-forming (SF) galaxies only, the median SFR is constant at z0.5 but declines by ∼0.3-0.4 dex from the field to clusters for satellites and centrals at z0.5. We argue that for satellites, the main role of the cosmic web environment is to control their SF fraction, whereas for centrals, it is mainly to control their overall SFR at z0.5 and to set their fraction at z0.5. We suggest that most satellites experience a rapid quenching mechanism as they fall from the field into clusters through filaments, whereas centrals mostly undergo a slow environmental quenching at z0.5 and a fast mechanism at higher redshifts. Our preliminary results highlight the importance of the large-scale cosmic web on galaxy evolution.

From voids to filaments: environmental transformations of galaxies in the SDSS

“…The filament-void pattern is well reproduced in cosmological simulations (Doroshkevich et al 1980;Klypin & Shandarin 1983;Davis et al 1985;Gramann 1993;Sheth & van de Weygaert 2004;Springel et al 2005). In recent years, filaments have been found to occur over the wide span of largescale density levels, residing inside voids and superclusters Sousbie et al 2011;Einasto et al 2012;Alpaslan et al 2014;Cautun et al 2014;Darvish et al 2017;Malavasi et al 2017).…”

Galaxy Zoo: the interplay of quenching mechanisms in the group environment★

“…Perhaps, instead, the correlation of increased quenched galaxy fractions with environment density is due to a superposition of other possible quenching mechanisms each of which depend on more local factors Blanton et al 2006;Cucciati et al 2010) than the broader environment properties Porter et al 2008;Fadda et al 2008;Darvish et al 2014Darvish et al , 2017Alpaslan et al 2016;Laigle et al 2017).…”

A 16 deg2 survey of emission-line galaxies at z < 1.5 in HSC-SSP Public Data Release 1

“…As a first step to address these important issues for understanding galaxy evolution, a more comprehensive sampling of star-forming galaxies at the redshifts of z < ∼ 3 is required that covers a wide range in terms of star formation activity and environment. Recent studies have indeed demonstrated the importance of investigating galaxy properties along the cosmic web (e.g., Darvish et al 2014;Darvish et al 2015;Darvish et al 2016;Darvish et al 2017;Malavasi et al 2017;Laigle et al 2017;Kuutma et al 2017). …”