arrow
Return

Relativistic effects on galaxy redshift samples due to target selection

delete2017-07-06
delete8
delete
OA
AI
S
Shadab Alam *
R
Rupert A. C. Croft
S
Shirley Ho
H
Hongyu Zhu
E
Elena Giusarma
DOI:10.1093/mnras/stx1684delete
deleteOriginal
deleteShare
deleteSave
View PDF
Abstract

Abstract

En 中文
In a galaxy redshift survey, the objects to be targeted for spectra are selected from a photometrically observed sample. The observed magnitudes and colours of galaxies in this parent sample will be affected by their peculiar velocities, through relativistic Doppler and relativistic beaming effects. In this paper, we compute the resulting expected changes in galaxy photometry. The magnitudes of the relativistic effects are a function of redshift, stellar mass, galaxy velocity and velocity direction. We focus on the CMASS sample from the Sloan Digital Sky Survey (SDSS) and Baryon Oscillation Spectroscopic Survey (BOSS), which is selected on the basis of colour and magnitude. We find that 0.10 per cent of the sample (similar to 585 galaxies) has been scattered into the targeted region of colour-magnitude space by relativistic effects, and conversely 0.09 per cent of the sample (similar to 532 galaxies) has been scattered out. Observational consequences of these effects include an asymmetry in clustering statistics, which we explore in a companion paper. Here, we compute a set of weights that can be used to remove the effect of modulations introduced into the density field inferred from a galaxy sample. We conclude by investigating the possible effects of these relativistic modulation on large-scale clustering of the galaxy sample.
Keywords:
gravitation
relativistic processes
galaxies: statistics
cosmological parameters
large-scale structure of Universe
cosmology: observations
AI Summary

AI Summary

Key information extracted from the uploaded paper, including a brief overview, abstract, background, key highlights, visual analysis, and future outlook.

Journal

Monthly Notices of the Royal Astronomical Society cover
Monthly Notices of the Royal Astronomical Society
IF:
4.8
Papers:
7.0W
Citations:
25.0W

Organization

C
Carnegie Mellon University
Scholars:
1.4W
Papers: 1.4W
Citations: 2.7W