Linear Redshift Distortions: a Review
Abstract
Redshift maps of galaxies in the Universe are distorted by the peculiar velocities of galaxies along the line of sight. The amplitude of the distortions on large, linear scales yields a measurement of the linear redshift distortion parameter, which is $\beta \approx \Omega_0^{0.6}/b$ in standard cosmology with cosmological density $\Omega_0$ and light-to-mass bias $b$. All measurements of $\beta$ from linear redshift distortions published up to mid 1997 are reviewed. The average and standard deviation of the reported values is $\beta_{optical} = 0.52 \pm 0.26$ for optically selected galaxies, and $\beta_{IRAS} = 0.77 \pm 0.22$ for IRAS selected galaxies. The implied relative bias is $b_{optical}/b_{IRAS} \approx 1.5$. If optical galaxies are unbiased, then $\Omega_0 = 0.33^{+0.32}_{-0.22}$, while if IRAS galaxies are unbiased, then $\Omega_0 = 0.63^{+0.35}_{-0.27}$.
- Publication:
-
The Evolving Universe
- Pub Date:
- 1998
- DOI:
- 10.1007/978-94-011-4960-0_17
- arXiv:
- arXiv:astro-ph/9708102
- Bibcode:
- 1998ASSL..231..185H
- Keywords:
-
- Astrophysics
- E-Print:
- 91 pages, including 8 embedded EPS figures. LaTeX, crckapb.sty. Final version of invited review to appear in Hamilton, D. (ed.) Ringberg Workshop on Large-Scale Structure, held at Ringberg Castle, Germany, 23-28 September 1996, Kluwer Academic, Dordrecht. Numerous minor revisions, some errors fixed. One major revision: careful discussion of difference between real and redshift selection function