Strong gravitational lensing in MS1455+22
Abstract
Strong gravitational lensing occurs in the luminous X-ray cluster MS1455+22, producing a tangential and a radial arc. Both of these features can be modeled as the lensed image of a single source in the distant background past a dark matter halo. This halo is modeled equally well by a psuedo-isothermal density profile or a density following the ``universal'' profile recently proposed by Navarro, Frenk, & White. The models predict a third image which may have an optical counterpart. Recent work by Miralda-Escude suggests that the presence of even a relatively small central cD galaxy can greatly effect the strong lensing properties of the cluster. In particular, a central cD component can inhibit the formation of a radial arc which would otherwise appear in the dark matter lens. The observation of a radial arc therefore limits the mass of the cD. Based on numerical modeling, we find an upper limit for the mass-to-light ratio of the stellar component of the cD, beyond which the observed tangential and radial arcs cannot be images of the same background source. This limit is much lower than the typical mass-to-light ratio of an isolated elliptical galaxy, implying that the luminous cD galaxy has little, if any, dark matter beyond that associated with the cluster as a whole.
- Publication:
-
American Astronomical Society Meeting Abstracts #189
- Pub Date:
- January 1997
- Bibcode:
- 1997AAS...18912219N