Imprints of relativistic effects on the asymmetry of the halo cross-correlation function: from linear to non-linear scales. Issue 2 (29th November 2018)

• Record Type: Journal Article
• Authors: Breton, Michel-Andrès; Rasera, Yann; Taruya, Atsushi; Lacombe, Osmin; Saga, Shohei
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 483:Issue 2(2019)
• Page Start: 2671
• Page End: 2696
• Publication Date: 2018-11-29
• Subjects: gravitational lensing: weak -- methods: numerical -- galaxies: distances and redshifts -- large-scale structure of Universe; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/sty3206
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: The apparent distribution of large-scale structures in the Universe is sensitive to the velocity/potential of the sources as well as the potential along the line of sight through the mapping from real space to redshift space (redshift-space distortions, RSD). Since odd multipoles of the halo cross-correlation function vanish when considering standard Doppler RSD, the dipole is a sensitive probe of relativistic and wide-angle effects. We build a catalogue of ten million haloes (Milky Way size to galaxy-cluster size) from the full-sky light cone of a new 'RayGalGroupSims' N -body simulation which covers a volume of (2.625 h −1 Gpc) 3 with 4096 3 particles. Using ray-tracing techniques, we find the null geodesics connecting all the sources to the observer. We then self-consistently derive all the relativistic contributions (in the weak-field approximation) to RSD: Doppler, transverse Doppler, gravitational, lensing and integrated Sachs–Wolfe. It allows us, for the first time, to disentangle all contributions to the dipole from linear to non-linear scales. At large scale, we recover the linear predictions dominated by a contribution from the divergence of neighbouring line of sights. While the linear theory remains a reasonable approximation of the velocity contribution to the dipole at non-linear scales it fails to reproduce the potential contribution below 30–60 h −1 Mpc (depending on the halo mass). At scales smaller than ∼10 h −1 Mpc, the dipole is dominated by the asymmetry caused by the gravitational redshift. The transition between the two regimes is mass dependent as well. We also identify a new non-trivial contribution from the non-linear coupling between potential and velocity terms.