Mass and Dust in the Disk of a Spiral Lens Galaxy
Abstract
Gravitational lensing is a potentially important probe of spiral galaxy structure, but only a few cases of lensing by spiral galaxies are known. We present Hubble Space Telescope and Magellan observations of the two-image quasar PMN J2004-1349, revealing that the lens galaxy is a spiral galaxy. One of the quasar images passes through a spiral arm of the galaxy and suffers 3 mag of V-band extinction. Using simple lens models, we show that the mass quadrupole is well aligned with the observed galaxy disk. A more detailed model with components representing the bulge and disk gives a bulge-to-disk mass ratio of 0.16+/-0.05. The addition of a spherical dark halo, tailored to produce an overall flat rotation curve, does not change this conclusion.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 2003
- DOI:
- 10.1086/378637
- arXiv:
- arXiv:astro-ph/0308093
- Bibcode:
- 2003ApJ...597..672W
- Keywords:
-
- Cosmology: Dark Matter;
- ISM: Dust;
- Extinction;
- galaxies: spiral;
- structure;
- halos;
- Cosmology: Gravitational Lensing;
- Galaxies: Quasars: Individual: Alphanumeric: PMN J2004-1349;
- Astrophysics
- E-Print:
- ApJ, in press [9pp, 7 figs]