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Optimizing high redshift galaxy surveys for environmental information

Published version
Peer-reviewed

Change log

Authors

Looser, Tobias J 
Lilly, Simon J 
Sin, Larry PT 
Henriques, Bruno MB 

Abstract

We investigate the performance of group finding algorithms that reconstruct galaxy groups from the positional information of tracer galaxies that are observed in redshift surveys carried out with multiplexed spectrographs. We use mock light-cones produced by the L-Galaxies semi-analytic model of galaxy evolution in which the underlying reality is known. We particularly focus on the performance at high redshift, and how this is affected by choices of the mass of the tracer galaxies (largely equivalent to their co-moving number density) and the (assumed random) sampling rate of these tracers. We first however compare two different approaches to group finding as applied at low redshift, and conclude that these are broadly comparable. For simplicity we adopt just one of these, "Friends-of-Friends" (FoF) as the basis for our study at high redshift. We introduce 12 science metrics that are designed to quantify the performance of the group-finder as relevant for a wide range of science investigations with a group catalogue. These metrics examine the quality of the recovered group catalogue, the median halo masses of different richness structures, the scatter in dark matter halo mass and how successful the group-finder classifies singletons, centrals and satellites. We analyze how these metrics vary with the limiting stellar mass and random sampling rate of the tracer galaxies, allowing quantification of the various trade-offs between different possible survey designs. Finally, we look at the impact of these same design parameters on the relative "costs" in observation time of the survey using as an example the potential MOONRISE survey using the MOONS instrument.

Description

Keywords

astro-ph.CO, astro-ph.CO

Journal Title

Monthly Notices of the Royal Astronomical Society

Conference Name

Journal ISSN

0035-8711
1365-2966

Volume Title

504

Publisher

Royal Astronomical Society

Rights

All rights reserved
Sponsorship
Science and Technology Facilities Council (ST/M001172/1)
European Research Council (695671)
Science and Technology Facilities Council (ST/L006189/1)
STFC (ST/V000918/1)
ERC STFC