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arXiv · astro-ph/9708170

Weighing a galaxy bar in the lens Q2237+0305

Robert Schmidt·Rachel L. Webster·Geraint F. Lewis
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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.

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Robert Schmidt, Rachel L. Webster, Geraint F. Lewis. 1997-08-19. Weighing a galaxy bar in the lens Q2237+0305. https://doi.org/10.1046/j.1365-8711.1998.01326.x

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