Weighing a galaxy bar in the lens Q2237 +=0305 |
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| Authors: | RobertSchmidt Rachel LWebster Geraint FLewis |
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| Institution: | School of Physics, University of Melbourne, Parkville, Victoria 3052, Australia; SUNY at Stony Brook, Stony Brook, NY 11794-2100, USA |
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| Abstract: | In the gravitational lens system Q2237+0305 the cruciform quasar image geometry is twisted by 10c 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 ∼ 1.5) −108 h −175 M⊙ in the region inside the quasar images. |
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| Keywords: | galaxies: fundamental parameters galaxies: individual: 2237+0305 galaxies: spiral gravitational lensing |
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