1999ApJ...516...18R

We employ Schwarzschild's method of the orbit modeling to constrain the mass profiles of the central lens galaxies in Q0957+561 and PG 1115+080. We combine the measured, central projected stellar velocity dispersions of these galaxies with the self-similar radial profiles of the rms velocity and of the Gauss-Hermite moment h₄ observed in nearby galaxies for 0≲R≲2R_eff. For Q0957+561, we find a 16% uncertainty in the galaxy mass and formal 2 σ limits on the Hubble constant of H₀=61⁺¹³_–15 km.s^–1.Mpc^–1. For PG 1115+080, we find that none of the viable lens models can be ruled out, so that H₀ is not yet strongly constrained by this system.