University of Sussex
Browse
MNRAS-2001-Sharpe-121-30.pdf (305.68 kB)

Predicting the peculiar velocities of nearby PSCz galaxies using the Least Action Principle

Download (305.68 kB)
journal contribution
posted on 2023-06-08, 08:39 authored by J Sharpe, M Rowan-Robinson, A Canavezes, W Saunders, E Branchini, G Efstathiou, C Frenk, O Keeble, R G McMahon, S Maddox, Seb OliverSeb Oliver, W Sutherland, H Tadros, S D M White
We use the Least Action Principle to predict the peculiar velocities of PSCz galaxies inside cz=2000 km s-1. Linear theory is used to account for tidal effects to cz=15 000 km s-1, and we iterate galaxy positions to account for redshift distortions. As the Least Action Principle is valid beyond linear theory, we can predict reliable peculiar velocities even for very nearby galaxies (i.e., cz=500 km s-1). These predicted peculiar velocities are then compared with the observed velocities of 12 galaxies with Cepheid distances. The combination of the PSCz galaxy survey (with its large sky coverage and uniform selection) with the accurate Cepheid distances makes this comparison relatively free from systematic effects. We find that galaxies are good tracers of the mass, even at small (=10 h-1 Mpc) scales; under the assumption of no biasing, 0.25=ß=0.75 (at 90 per cent confidence). We use the reliable predicted peculiar velocities to estimate the Hubble constant H0 from the local volume without ‘stepping up’ the distance ladder, finding a confidence range of 65–75 km s-1 Mpc-1 (at 90 per cent confidence).

History

Publication status

  • Published

File Version

  • Published version

Journal

Monthly Notices of the Royal Astronomical Society

ISSN

0035-8711

Publisher

Oxford University Press

Issue

1

Volume

322

Page range

121-130

Department affiliated with

  • Physics and Astronomy Publications

Full text available

  • Yes

Peer reviewed?

  • Yes

Legacy Posted Date

2012-02-06

First Open Access (FOA) Date

2016-03-22

First Compliant Deposit (FCD) Date

2016-11-16

Usage metrics

    University of Sussex (Publications)

    Categories

    No categories selected

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC