Astronomy and Astrophysics – Astrophysics
Scientific paper
2003-06-04
Astron.Astrophys. 408 (2003) 171
Astronomy and Astrophysics
Astrophysics
13 pages, 8 figures (7 in jpg), accepted by A&A, also available from http://vela.astro.ulg.ac.be/Preprints/P81/index.html
Scientific paper
10.1051/0004-6361:20030847
We present the very first high quality images of the HeII 4686 emission in three high excitation nebulae of the Magellanic Clouds. A fourth high excitation nebula, situated around the WR star BAT99-2, was analysed in a previous letter. Using VLT FORS data, we investigate the morphology of the ring nebulae around the early-type WN stars BAT99-49 & AB7. We derive the total HeII fluxes for each object and compare them with the most recent theoretical WR models. Using Halpha, [OIII] and HeI 5876 images along with long-slit spectroscopy, we investigate the physical properties of these ring nebulae and find only moderate chemical enrichment. We also surveyed seven other LMC WR stars but we failed to detect any HeII emission but note that the nebula around BAT99-11 shows a N/O ratio and an oxygen abundance slightly lower than the LMC values, while the nebula around BAT99-134 presents moderate chemical enrichment similar to the one seen near BAT99-2, 49 and AB7. The third high excitation nebula presented in this paper, N44C, does not harbor stars hotter than mid-O main sequence stars. It was suggested to be a fossil X-ray nebula ionized but our observations of N44C reveal no substantial changes in the excitation compared to previous results reported in the literature.
Chu Y.-H. Y.-H.
Manfroid Jean
Naze Yael
Rauw Gregor
Vreux Jean-Marie
No associations
LandOfFree
WR bubbles and HeII emission does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with WR bubbles and HeII emission, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and WR bubbles and HeII emission will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-130236