Other
Scientific paper
Jan 1995
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995apj...438..514m&link_type=abstract
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 438, no. 2, p. 514-526
Other
68
Astronomical Models, Density (Mass/Volume), Elliptical Galaxies, Galactic Clusters, Galactic Mass, Gravitational Lenses, Curves (Geometry), Images, Radii, Velocity
Scientific paper
We study the constraints on the density profile of the mass in a cluster of galaxies that can be obtained when a radial arc produced by gravitational lensing is observed. We apply this to the cluster MS 2137-23, which contains a radial arc, a tangential arc, and three other arclets. As shown by Mellier and coworkers, the positions and elongations of all these five images are well reproduced as arising from two different background galaxies, if the mass distribution in the cluster is elliptical, is exactly centered on the brightest cluster galaxy, and has the same ellipticity and position angle as this galaxy. The galaxy is therefore identified as the center of the cluster potential well. We show that the ratio thetar/thetai of the distance from the radial arc to the center of the cluster to the distance from the other image of the same source to the center gives a powerful constraint on the form of the dark matter density profile. Models that are favored have well-defined core radii of approximately 30/h kpc, with the slope changing rapidly from almost flat to roughly isothermal around this radius. All the models for the density profile that are consistent with the observed position of the radial arc predict a velocity dispersion for the cluster galaxies of approximately 1200 km/s and a central velocity dispersion for the stars of approximately 350 km/s, consistent with the observed velocity dispersions in other cD galaxies. The models also predict that the velocity dispersion of the cD halo should rise rapidly with radius and that the two sources producing the five arcs should be at similar redshifts. This can be tested by future observations.
No associations
LandOfFree
Gravitational lensing by a cluster of galaxies and the central cD galaxy: Measuring the mass profile 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 Gravitational lensing by a cluster of galaxies and the central cD galaxy: Measuring the mass profile, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gravitational lensing by a cluster of galaxies and the central cD galaxy: Measuring the mass profile will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1818994