Astronomy and Astrophysics – Astrophysics
Scientific paper
2004-04-21
IAU Colloq. 195 (Cambridge Univ. Press), p. 413 (2004)
Astronomy and Astrophysics
Astrophysics
5 pages, oral presentation at IAU Colloquium 195, Outskirts of Galaxy Clusters: intense life in the suburbs, ed. A. Diaferio
Scientific paper
10.1017/S1743921304000869
We provide the first direct lifting of the mass/anisotropy degeneracy for a cluster of galaxies, by jointly fitting the line of sight velocity dispersion and kurtosis profiles of the Coma cluster, assuming an NFW tracer density profile, a generalized-NFW dark matter profile and a constant anisotropy profile. We find that the orbits in Coma must be quasi-isotropic, and find a mass consistent with previous analyses, but a concentration parameter 50% higher than expected in cosmological N-body simulations. We then test the accuracy of our method on realistic non-spherical systems with substructure and streaming motions, by applying it to the ten most massive structures in a cosmological N-body simulation. We find that our method yields fairly accurate results on average (within 20%), although with a wide variation (factor 1.7 at 1 sigma) for the concentration parameter, with decreased accuracy and efficiency when the projected mean velocity is not constant with radius.
Lokas Ewa L.
Mamon Gary A.
Sanchis Teresa
No associations
LandOfFree
Breaking the mass / anisotropy degeneracy in the Coma cluster 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 Breaking the mass / anisotropy degeneracy in the Coma cluster, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Breaking the mass / anisotropy degeneracy in the Coma cluster will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-17914