The Abell 35 Nebula Inside Out

Abstract

We present deep 6 cm continuum and narrowband optical emission-line images in Hα λ6563, [O III] λ5007, [O II] λ3727, and [N II] λ6584 of the Abell 35 planetary nebula (PN), showing its unique features. First, surrounding the central binary system, there is a bow shock, best seen predominantly in [O III], possibly weakly in Hα, and not at all in [O II], [N II], or 6 cm continuum. Fabry-Perot [O III] data are also presented which constrain the bow shock kinematical parameters. Second, external to the central bow shock, there are two prominent parallel nebular features (the "pipes"), seen at 6 cm continuum and in Hα, [O II], and [N II], which suggest dynamical interaction between the nebular material and the interstellar medium. Fabry-Perot [N II] data provide the kinematical parameters for the pipes. Archival IUE spectra are also presented which indicate that the temperature due to the hot companion with its accretion disk is on the order of 150,000 K. We derive a mass-loss rate of ≤3.0 × 10^-10 M_sun yr^-1, a systemic wind velocity of ≥530 km s^-1, and a total nebular mass of ∼0.23 M_sun. We discuss the data presented here in the context of a binary system with a systemic wind moving at Mach 1.3 with respect to the PN medium to give rise to the bow shock morphology. Further, we also discuss the PN-ISM interaction as a Mach 10 shock which gives rise to two prominent linear features as a result of an inhomogeneous PN ejection mechanism.