Weighing a galaxy bar in the lens Q2237+0305
Astrophysics
2009-10-30 v1
Abstract
In the gravitational lens system Q2237+0305 the cruciform quasar image geometry is twisted by ten degrees by the lens effect of a bar in the lensing galaxy. This effect can be used to measure the mass of the bar. We construct a new lensing model for this system with a power-law elliptical bulge and a Ferrers bar. The observed ellipticity of the optical isophotes of the galaxy leads to a nearly isothermal elliptical profile for the bulge with a total quasar magnification of 16^{+5}_{-4}. We measure a bar mass of 7.5\pm1.5 \times 10^8 h^{-1}_{75} M_{\sun} in the region inside the quasar images.
Keywords
Cite
@article{arxiv.astro-ph/9708170,
title = {Weighing a galaxy bar in the lens Q2237+0305},
author = {Robert Schmidt and Rachel L. Webster and Geraint F. Lewis},
journal= {arXiv preprint arXiv:astro-ph/9708170},
year = {2009}
}
Comments
9 pages, 5 Postscript figures, uses mn.sty and eps.sty, submitted to MNRAS