TY  - JOUR
A1  - Mesa-Delgado, A.
A1  - Esteban, C.
A1  - García-Rojas, J.
T1  - Ring Nebulae
BT  - Tracers of the CNO Nucleosynthesis
JF  - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015
N2  - Preliminary results are presented from spectroscopic data in the optical range of the Galactic ring nebulae NGC 6888, G2:4+1:4, RCW 58 and Sh2-308. Deep observations with long exposure times were carried out at the 6.5m Clay Telescope and at the 10.4m Gran Telescopio Canarias. In NGC 6888, recombination lines of C ii, O ii and N ii are detected with signal-to-noise ratios higher than 8. The chemical content of NGC 6888 is discussed within the chemical enrichment predicted by evolution models of massive stars. For all nebulae, a forthcoming work will content in-depth details about observations, analysis and final results (Esteban et al. 2015, in prep.).
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88299
SP  - 325
EP  - 328
ER  - 
TY  - JOUR
A1  - Reyes-Pérez, J.
A1  - Morisset, C.
A1  - Pena, M.
A1  - Mesa-Delgado, A.
T1  - A consistent spectral model of WR 136 and its associated bubble NGC 6888
JF  - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015
N2  - We analyse whether a stellar atmosphere model computed with the code CMFGEN provides an optimal description of the stellar observations of WR 136 and simultaneously reproduces the nebular observations of NGC 6888, such as the ionization degree, which is modelled with the pyCloudy code. All the observational material available (far and near UV and optical spectra) were used to constrain such models. We found that the stellar temperature T∗, at τ = 20, can be in a range between 70 000 and 110 000 K, but when using the nebula as an additional restriction, we found that the stellar models with T∗ ∼ 70 000 K represent the best solution for both, the star and the nebula.
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88274
SP  - 321
EP  - 324
ER  -