Characterizing HOD in filaments and nodes of the cosmic web

PEREZ, NOELIA; PEREYRA, LUIS A; COLDWELL, GEORGINA; RODRÍGUEZ, FACUNDO; ALFARO, IGNACIO G.; RUIZ, ANDRÉS N.

Monthly Notices of the Royal Astronomical Society

Oxford University Press

Año: 2024 vol. 528 p. 3186 - 3197

The standard paradigm for the formation of the Universe suggests that large structures are formed from hierarchical clusteringby the continuous accretion of less massive galaxy systems through filaments. In this context, filamentary structures playan important role in the properties and evolution of galaxies by connecting high-density regions, such as nodes, and beingsurrounded by low-density regions, such as cosmic voids. The availability of the filament and critical point catalogues extractedby DISPERSE from the ILLUSTRIS TNG300-1 hydrodynamic simulation allows a detailed analysis of these structures. The halooccupation distribution (HOD) is a powerful tool for linking galaxies and dark matter haloes, allowing constrained models ofgalaxy formation and evolution. In this work, we combine the advantage of halo occupancy with information from the filamentnetwork to analyse the HOD in filaments and nodes. In our study, we distinguish the inner regions of cosmic filaments and nodesfrom their surroundings. The results show that the filamentary structures have a similar trend to the total galaxy sample coveringa wide range of densities. In the case of the nodes sample, an excess of faint and blue galaxies is found for the low-mass haloessuggesting that these structures are not virialized and that galaxies may be continuously falling through the filaments. Instead,the higher mass haloes could be in a more advanced stage of evolution showing features of virialized structures.