Authors:
Aller, A.;Miranda, L. F.;Olguín, L.;Solano, E.;Ulla, A.
Journal:
Monthly Notices of the Royal Astronomical Society
Abstract:
RWT 152 is one of the few known planetary nebulae with an sdO central star. We present subarcsecond red tunable filter Hα imaging and intermediate-resolution, long-slit spectroscopy of RWT 152 obtained with OSIRIS/GTC with the goal of analyzing its properties. The Hα image reveals a bipolar nebula with a bright equatorial region and multiple bubbles in the main lobes. A faint circular halo surrounds the main nebula. The nebular spectra reveal a very low-excitation nebula with weak emission lines from H<SUP>+</SUP>, He<SUP>+</SUP>, and double-ionized metals, and absence of emission lines from neutral and single-ionized metals, except for an extremely faint [N II] λ6584 emission line. These spectra may be explained if RWT 152 is a density-bounded planetary nebula. Low nebular chemical abundances of S, O, Ar, N, and Ne are obtained in RWT 152, which, together with the derived high peculiar velocity (̃ 92-131 km s<SUP>-1</SUP>), indicate that this object is a halo planetary nebula. The available data are consistent with RWT 152 evolving from a low-mass progenitor (̃ 1 M<SUB>☉</SUB>) formed in a metal-poor environment.
URL:
https://ui.adsabs.harvard.edu/#abs/2016MNRAS.462.3945A/abstract
Keywords:
planetary nebulae: individual: RWT 152;hot subdwarfs;ISM: abundances;Astrophysics - Solar and Stellar Astrophysics