The radial velocities of planetary nebulae in NGC 3379

We present the results of a radial velocity survey of planetary nebulae (PNs) in the normal elliptical galaxy NGC 3379 performed with the Kitt Peak 4 m telescope and the NESSIE multifiber spectrograph. In two half-nights, we measured 29 PNs with projected galactocentric distances between 0.4 and 3.8 effective radii (1 < R < 10 kpc) with an observational uncertainty of ∼7 km s^-1. These data extend 3 times further into the halo than any previous absorption-line velocity study. The velocity dispersion and photometric profile of the galaxy agrees extremely well with that expected from a constant mass-to-light ratio, isotropic orbit Jaffe model with M/L_B ∼ 7; the best-fitting anisotropic models from a quadratic programming algorithm also give M/L_B ∼ 1. The data are consistent with models that contain no dark matter within 3.5 effective radii of the galaxy's nucleus.