Abstract
ABSTRACT 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.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.