The dependence of galaxy clustering on tidal environment in the Sloan Digital Sky Survey

Author(s)
Aseem Paranjape, Oliver Hahn, Ravi K. Sheth
Abstract

The influence of the Cosmic Web on galaxy formation and evolution is of great observational and theoretical interest. We investigate whether the Cosmic Web leaves an imprint in the spatial clustering of galaxies in the Sloan Digital Sky Survey (SDSS), using the group catalogue of Yang et al. and tidal field estimates at ∼2 h-1 Mpc scales from the mass-tides-velocity data set of Wang et al. We use the tidal anisotropy α (Paranjape et al.) to characterize the tidal environment of groups, and measure the redshift-space 2-point correlation function (2pcf) of group positions and the luminosity- and colour-dependent clustering of group galaxies using samples segregated by α. We find that all the 2pcf measurements depend strongly on α, with factors of ∼20 between the large-scale 2pcf of objects in the most and least isotropic environments. To test whether these strong trends imply `beyond halo mass' effects for galaxy evolution, we compare our results with corresponding 2pcf measurements in mock catalogues constructed using a halo occupation distribution that uses only halo mass as an input. We find that this prescription qualitatively reproduces all observed trends, and also quantitatively matches many of the observed results. Although there are some statistically significant differences between our `halo mass only' mocks and the data - in the most and least isotropic environments - which deserve further investigation, our results suggest that if the tidal environment induces additional effects on galaxy properties other than those inherited from their host haloes, then these must be weak.

Organisation(s)
Department of Astrophysics, Department of Mathematics
External organisation(s)
Inter-University Centre for Astronomy and Astrophysics India, Université Côte d'Azur, The Abdus Salam International Center for Theoretical Physics, Strada Costiera, 11, Trieste I-34151, Italy, University of Pennsylvania
Journal
Monthly Notices of the Royal Astronomical Society
Volume
476
Pages
5442-5452
ISSN
0035-8711
DOI
https://doi.org/10.1093/mnras/sty633
Publication date
06-2018
Peer reviewed
Yes
Austrian Fields of Science 2012
103044 Cosmology, 103004 Astrophysics
Keywords
Portal url
https://ucrisportal.univie.ac.at/en/publications/3868eb94-2e0d-4006-97c3-f332fb0c0dc3