Reference : The strange case of the massive binary HD 149404
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
http://hdl.handle.net/2268/15962
The strange case of the massive binary HD 149404
English
Rauw, Grégor mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Groupe d'astrophysique des hautes énergies (GAPHE) - Sciences spatiales >]
Nazé, Yaël mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Sciences spatiales >]
Carrier, F. [Observatoire de Genève, 1290 Sauverny, Switzerland]
Burki, G. [Observatoire de Genève, 1290 Sauverny, Switzerland]
Gosset, Eric mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Groupe d'astrophysique des hautes énergies (GAPHE) >]
Vreux, Jean-Marie [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > > ]
1-Mar-2001
Astronomy and Astrophysics
EDP Sciences
368
212-224
Yes (verified by ORBi)
International
0004-6361
1432-0746
Les Ulis
France
[en] STARS: EARLY-TYPE ; BINARIES: SPECTROSCOPIC ; STARS: INDIVIDUAL: HD 149404
[en] We report the analysis of an extensive set of high-resolution spectroscopic observations of the massive binary system HD 149404. We compare different techniques to measure the radial velocities of the heavily blended absorption lines and we derive a new orbital solution. The absorption lines display strong variability that slightly affects the orbital solution and the determination of the spectral types of the components of the binary. We find that the primary is probably of spectral type O7.5 I(f), while the secondary is most likely an ON9.7 I supergiant. The secondary seems to be the most evolved component of the system and its current evolutionary status could best be explained if the system has undergone a Roche lobe overflow episode during the past. The secondary could actually still be rather close to filling its critical volume and this could lead to an enhanced mass loss of the secondary. The spectrum of HD 149404 displays many emission lines some of which show phase-locked line profile variations. In particular, the Halpha line displays a double-peaked morphology at orbital phases near conjunction. We investigate the radial velocity behaviour of the emission lines and we find that some of them must be formed in an interaction region. We propose a simple model where some of the optical emission lines arise in a heavily bended shock region. Based on observations collected at the European Southern Observatory (La Silla, Chile) and at the Cerro Tololo Inter-American Observatory (CTIO).
http://hdl.handle.net/2268/15962
10.1051/0004-6361:20000527
http://adsabs.harvard.edu/abs/2001A%26A...368..212R

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