How reliable is the kinematical evidence for dark matter: the effects of non-sphericity, substructure and streaming motions

Details How reliable is the kinematical evidence for dark matter: the effects of non-sphericity, substructure and streaming motions How reliable is the kinematical evidence for dark matter: the effects of non-sphericity, substructure and streaming motions

2003-06-25

arxiv.org/abs/astro-ph/0306520v2

Mon.Not.Roy.Astron.Soc.347:1198,2004

Astronomy and Astrophysics

Astrophysics

12 pages, 12 figures. Revised version accepted for publication in MNRAS. More halos analyzed

Scientific paper

10.1111/j.1365-2966.2004.07295.x

Using cosmological $N$-body simulations of dark matter haloes, we study the effects of non-sphericity, substructure and streaming motions in reproducing the structure and internal kinematics of clusters of galaxies from kinematical measurements. Fitting an NFW model to the 3D density profile, we determine the virial mass, concentration parameter and velocity anisotropy of the haloes, and then calculate the profiles of projected velocity moments, as they would be measured by a distant observer. Using these mock data, we apply a Jeans analysis for spherical objects to reproduce the line-of-sight velocity dispersion and kurtosis and fit the three parameters. We find that the line-of-sight velocity dispersion and kurtosis profiles of a given halo can vary considerably with the angle of view of the observer. We show that the virial mass, concentration parameter and velocity anisotropy of the haloes can be reproduced satisfactorily independently of the halo shape, although the virial mass tends to be underestimated, the concentration parameter overestimated, while the recovered anisotropy is typically more tangential than the true one. The mass, concentration and velocity anisotropy of haloes are recovered with better precision when their mean velocity profiles are near zero.

Affiliated with

Also associated with

No associations

Rating

How reliable is the kinematical evidence for dark matter: the effects of non-sphericity, substructure and streaming motions 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 How reliable is the kinematical evidence for dark matter: the effects of non-sphericity, substructure and streaming motions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and How reliable is the kinematical evidence for dark matter: the effects of non-sphericity, substructure and streaming motions will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-68558