We present Hubble Space Telescope images and 2 years of optical photometry of the quadruple quasar HE 0435-1223. The time delays between the intrinsic quasar variations are Δ/AD = -14.37-0.85+0.75, ΔtAB = -8.00-0.82-0.73, and Δt AC = -2.10-0.71+0.78 days. We also observed nonintrinsic variations of ∼0.1 mag yr-1 that we attribute to microlensing. Instead of the traditional approach of assuming a rotation curve for the lens galaxy and then deriving the Hubble constant (H0), we assume H0 = (72 ± 7) km s-1 Mpc-1 and derive constraints on the rotation curve. On the scale over which the lensed images occur (1″2 = 5 h-1 kpc ≃ 1.5Re), the lens galaxy must have a rising rotation curve, and it cannot have a constant mass-to-light ratio. These results add to the evidence that the structures of earlytype galaxies are heterogeneous.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science
- Cosmological parameters
- Dark matter
- Galaxies: kinematics and dynamics gravitational lensing
- Quasars: individual (HE 0435-1223)