Anisotropic effective redshift and evolving clustering amplitude

Bibliographic Details
Title: Anisotropic effective redshift and evolving clustering amplitude
Authors: Obuljen, Andrej, Percival, Will J.
Publication Year: 2021
Collection: Astrophysics
Subject Terms: Astrophysics - Cosmology and Nongalactic Astrophysics
More Details: A typical galaxy survey geometry results in galaxy pairs of different separation and angle to the line-of-sight having different distributions in redshift and consequently a different effective redshift. However, clustering measurements are analysed assuming that the clustering is representative of that at a single effective redshift. We investigate the impact of variations in the galaxy-pair effective redshift on the large-scale clustering measured in galaxy surveys. We find that galaxy surveys spanning a large redshift range have different effective redshifts as a function of both pair separation and angle. Furthermore, when considering tracers whose clustering amplitude evolves strongly with redshift, this combination can result in an additional scale-dependent clustering anisotropy. We demonstrate the size of this effect on the eBOSS DR16 Quasar sample and show that, while the impact on monopole is negligible, neglecting this effect can result in a large-scale tilt of $\sim 4\%$ and $\sim40\%$ in quadrupole and hexadecapole, respectively. We discuss strategies to mitigate this effect when making measurements.
Comment: 7 pages, 7 figures. Comments welcome
Document Type: Working Paper
DOI: 10.1088/1475-7516/2021/11/006
Access URL: http://arxiv.org/abs/2104.07022
Accession Number: edsarx.2104.07022
Database: arXiv
More Details
DOI:10.1088/1475-7516/2021/11/006