Planetary nebulae with Wolf–Rayet-type central stars – III. A detailed view of NGC 6905 and its central star

We present a multiwavelength characterization of the planetary nebula (PN) NGC 6905 and its [Wolf–Rayet]-type ([WR]) central star (CSPN) HD 193949. Our Nordic Optical Telescope Alhambra Faint Object Spectrograph and Camera (ALFOSC) spectra and images unveil in unprecedented detail the high-ionizatio...

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Bibliographic Details
Authors: Gómez-González, V. M. A., Rubio, G., Toalá, Jesús A., Guerrero, Martín A., Sabin, L., Todt, H., Gómez-Llanos, V., Ramos-Larios, G., Mayya, Y. D.
Format: article
Status:Published version
Publication Date:2022
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/269050
Online Access:http://hdl.handle.net/10261/269050
Access Level:Open access
Keyword:Stars: evolution
Stars: individual: HD 193949
Stars: winds
Outflows
Stars: Wolf-Rayet
(ISM:) planetary nebulae: general
(ISM:) planetary nebulae: individual: NGC 6905
Description
Summary:We present a multiwavelength characterization of the planetary nebula (PN) NGC 6905 and its [Wolf–Rayet]-type ([WR]) central star (CSPN) HD 193949. Our Nordic Optical Telescope Alhambra Faint Object Spectrograph and Camera (ALFOSC) spectra and images unveil in unprecedented detail the high-ionization structure of NGC 6905. The high-quality spectra of HD 193949 allowed us to detect more than 20 WR features including the characteristic O-bump, blue bump, and red bump, which suggests a spectral type no later than a [WO2]-subtype. Moreover we detect the Ne VII and Ne VIII broad emission lines, rendering HD 193949 yet another CSPN with Teff ≲ 150 kK exhibiting such stellar emission lines. We studied the physical properties (Te and ne) and chemical abundances of different regions within NGC 6905 including its low-ionization clumps; abundances are found to be homogeneous. We used the PoWR stellar atmosphere code to model the spectrum of HD 193949, which is afterwards used in a photoionization model performed with CLOUDY that reproduces the nebular and dust properties for a total mass in the 0.31–0.47 M⊙ range and a mass of C-rich dust of ∼2 × 10−3 M⊙. Adopting a current stellar mass of 0.6 M⊙, our model suggests an initial mass ∼1 M⊙ for HD 193949, consistent with the observations. © 2021 The Author(s).