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

**Authors:** Behnam Darvish, Bahram Mobasher, D. Christopher Martin, David Sobral, Nick Z. Scoville, Andra Stroe, Shoubaneh Hemmati, Jeyhan Kartaltepe  
**arXiv:** [1611.05451](https://arxiv.org/abs/1611.05451)  
**Date:** 2016-11-16  
**Summary page:** https://www.summarizepaper.com/en/paper/1611.05451v1/

## Key points

- Behnam Darvish and colleagues study the cosmic web and its impact on galaxy evolution
- They use a mass complete sample of galaxies in the COSMOS field with accurate photometric redshifts
- The researchers construct the density field and cosmic web up to a redshift of 1.2
- They identify clusters, filaments, and the field using the density field Hessian matrix
- The authors provide the density field and cosmic web measures to the scientific community
- At redshifts lower than approximately 0.8, there is a gradual decline in median star-formation rate (SFR) from the field to clusters within the cosmic web
- This decline is more pronounced for satellite galaxies compared to central galaxies
- At higher redshifts (z > 0.8), this trend levels off for both overall galaxy population and satellites
- For star-forming galaxies, there is a constant median SFR at z > 0.5 but a decline from the field to clusters at z < 0.5
- Satellite galaxies' location within the cosmic web primarily influences their star-forming fraction while central galaxies' location controls their overall SFR at z < 0.5 and determines their fraction at z > 0.5
- Most satellites experience rapid quenching mechanisms as they transition from the field into clusters through filaments, while centrals undergo slow environmental quenching at z < 0.5 but faster mechanisms at higher redshifts.
- Large-scale cosmic structures significantly shape galaxy evolution by affecting star formation and quenching processes

## Summary

In their study, Behnam Darvish and colleagues utilize a mass complete sample of galaxies in the COSMOS field with accurate photometric redshifts to investigate the cosmic web and its impact on galaxy evolution. They construct the density field and cosmic web up to a redshift of 1.2, using the density field Hessian matrix to identify clusters, filaments, and the field. The authors provide the density field and cosmic web measures to the scientific community. The researchers find that at redshifts lower than approximately 0.8, there is a gradual decline in the median star-formation rate (SFR) from the field to clusters within the cosmic web. This decline is particularly pronounced for satellite galaxies, with a decrease of around 1 dex compared to approximately 0.5 dex for central galaxies. However, at higher redshifts (z > 0.8), this trend levels off for both the overall galaxy population and satellites. When considering only star-forming galaxies, they observe a constant median SFR at z > 0.5 but a decline of around 0.3-0.4 dex from the field to clusters for both satellites and centrals at z < 0.5. The authors propose that for satellites, their location within the cosmic web primarily influences their star-forming fraction while for central galaxies it mainly controls their overall SFR at z < 0.5 and determines their fraction at z > 0.5. Based on these findings Darvish et al suggest that most satellites experience rapid quenching mechanisms as they transition from the field into clusters through filaments whereas centrals undergo slow environmental quenching at z < 0.5 but experience faster mechanisms at higher redshifts. These preliminary results emphasize how significant large-scale cosmic structures are in shaping galaxy evolution by providing insights into how different regions of the cosmic web affect star formation and quenching processes; thus contributing to our understanding of this complex interplay between galaxies and their environments .