Astronomy and Astrophysics – Astrophysics
Scientific paper
1995-04-20
Astron.J. 110 (1995) 477
Astronomy and Astrophysics
Astrophysics
61 pages uuencoded, compressed postscript in 5 pieces. Also available in one piece at http://www.dao.nrc.ca/DAO/SCIENCE/scienc
Scientific paper
10.1086/117536
(compressed version) We combine the CfA Redshift Survey (CfA2) and the Southern Sky Redshift Survey (SSRS2) to estimate the pairwise velocity dispersion of galaxies $\sig12$ on a scale of $\sim 1 \hmpc$. Both surveys are complete to an apparent magnitude limit $B(0)=15.5$. Our sample includes 12,812 galaxies distributed in a volume $1.8 \times 10^6 \hmpc3$. We conclude: 1) The pairwise velocity dispersion of galaxies in the combined CfA2+SSRS2 redshift survey is $\sig12=540 \kms \pm 180 \kms$. Both the estimate and the variance of $\sig12$ significantly exceed the canonical values $\sig12=340 \pm40$ measured by Davis \& Peebles (1983) using CfA1. 2) We derive the uncertainty in $\sig12$ from the variation among subsamples with volumes on the order of $7 \times 10^5$ \hmpc3. This variation is nearly an order of magnitude larger than the formal error, 36 $\kms$, derived using least-squares fits to the CfA2+SSRS2 correlation function. This variation among samples is consistent with the conclusions of Mo \etal (1993) for a number of smaller surveys and with the analysis of CfA1 by Zurek \etal (1994). 3) When we remove Abell clusters with $R\ge1$ from our sample, the pairwise velocity dispersion of the remaining galaxies drops to $295 \pm 99 \kms$. Thus the dominant source of variance in $\sig12$ is the shot noise contributed by dense virialized systems. 4) The distribution of pairwise velocities is consistent with an isotropic exponential with velocity dispersion independent of scale.
da Costa Luiz Nicolaci
Geller Margaret J.
Huchra John P.
Marzke Ronald O.
No associations
LandOfFree
PAIRWISE VELOCITIES OF GALAXIES IN THE CFA AND SSRS2 REDSHIFT SURVEYS does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with PAIRWISE VELOCITIES OF GALAXIES IN THE CFA AND SSRS2 REDSHIFT SURVEYS, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and PAIRWISE VELOCITIES OF GALAXIES IN THE CFA AND SSRS2 REDSHIFT SURVEYS will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-405340