Open AccessOn the vorticity of flow in redshift space
Author(s) -
Chodorowski Michał J.,
Nusser Adi
Publication year - 1999
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1999.03084.x
Subject(s) - physics , redshift , conservative vector field , redshift space distortions , vector field , observer (physics) , peculiar velocity , galaxy , vorticity , gravitational field , limit (mathematics) , space (punctuation) , redshift survey , astrophysics , classical mechanics , mathematical analysis , quantum mechanics , vortex , mechanics , linguistics , philosophy , mathematics , compressibility
Given an irrotational (vorticity free) velocity field in real space, we prove that, in the distant observer limit and in the absence of multi‐valued zones, the associated velocity field in redshift space is also irrotational. The proof does not rely on any approximation to gravitational dynamics. The result can be particularly useful for the analysis of redshift distortions and for reconstruction methods of cosmological velocity fields from galaxy redshift surveys, in the non‐linear regime. Although the proof is restricted to the distant observer limit, we show that the POTENT method can be modified to derive the full real space velocity field as a function of the redshift space coordinate , thus avoiding spatial Malmquist biases.