Abstract
ABSTRACTWe present blue spectra of massive stars in the Local Group galaxies NGC 6822 and M33. For all the targets, selected from our previous Hubble Space Telescope WFPC2 photometry, no previous spectroscopic studies exist, to our knowledge, except for a bright Wolf‐Rayet star in NGC 6822. Photospheric parameters Teff and gravity are derived by a model fit of the Balmer lines and multiband (UV to optical) photometry combined and are compared with evolutionary models. Inferred masses range from ≈7 to ≈40 M⊙ in the sample. From the spectroscopy, we classify the Wolf‐Rayet star in NGC 6822 as WN3(‐4), with no hydrogen. We estimate its progenitor mass of ≈40 ± 10M⊙. For two stars in the NGC 6822 sample, our data are not sufficient to establish whether they are foreground stars toward NGC 6822 or they belong to the galaxy.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Publications of the Astronomical Society of the Pacific
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.
