The PN.S Elliptical Galaxy Survey: Data Reduction, Planetary Nebula Catalog, and Basic Dynamics for NGC 3379

We present results from Planetary Nebula Spectrograph (PN.S) observations ofthe elliptical galaxy NGC 3379 and a description of the data reductionpipeline. We detected 214 planetary nebulae of which 191 are ascribed to NGC3379, and 23 to the companion galaxy NGC 3384. Comparison with data from theliterature show that the PN.S velocities have an internal error of <20km/s anda possible offset of similar magnitude. We present the results of kinematicmodelling and show that the PN kinematics are consistent with absorption-linedata in the region where they overlap. The resulting combined kinematic dataset, running from the center of NGC 3379 out to more than seven effective radii(Reff), reveals a mean rotation velocity that is small compared to the randomvelocities, and a dispersion profile that declines rapidly with radius. From aseries of Jeans dynamical models we find the B-band mass-to-light ratio inside5 Reff to be 8 to 12 in solar units, and the dark matter fraction inside thisradius to be less than 40%. We compare these and other results of dynamicalanalysis with those of dark-matter-dominated merger simulations, finding thatsignificant discrepancies remain, reiterating the question of whether NGC 3379has the kind of dark matter halo that the current LambdaCDM paradigm requires.Comment: 21 pages, 15 figures, using emulateapj.cls. Accepted for publication in the Astrophysical Journa