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 (Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy/Gran Telescopio Canarias) with the goal of analysing 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+, He+ 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-1), 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⊙) formed in a metal-poor environment.
Original language | English |
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Pages (from-to) | 3945-3954 |
Number of pages | 10 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 462 |
Issue number | 4 |
DOIs | |
State | Published - 11 Nov 2016 |
Bibliographical note
Publisher Copyright:© 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.
Keywords
- ISM: abundances
- Planetary nebulae: individual: RWT 152
- Subdwarfs