References of "Nazé, Yaël"
     in
Bookmark and Share    
Full Text
See detailStars in the eyes, birth of a vocation ?
Nazé, Yaël ULg

in Astrophysics, and How to Attract Young People into Physics (2005, November 01)

It is generally difficult to interest people to sciences, especially physics. However, astronomy has a great power of fascination, and can thus be used to attract people into the scientific world. Here in ... [more ▼]

It is generally difficult to interest people to sciences, especially physics. However, astronomy has a great power of fascination, and can thus be used to attract people into the scientific world. Here in Liège, we are trying to develop several different aspects of astro-education: they will be detailed in this paper. For example, we organize interactive activities for primary schools, and also help high school students to consider a scientific career. Our undergraduate students also benefit from our experience: for example, they have the possibility to observe at a real observatory, they can train at ESA facilities,... The general public is also invited to discover astronomy and, through it, physics, thanks to several specific events. Finally, media, the links between the public and the researchers, are not forgotten: our astro-news service was specifically created for this purpose. [less ▲]

Detailed reference viewed: 10 (3 ULg)
Full Text
See detailThe peculiar Of?p stars HD 108 and HD 191612
Nazé, Yaël ULg; Rauw, Grégor ULg; Walborn, N. R. et al

in Massive Stars and High-Energy Emission in OB Associations (2005, November 01)

The Of?p spectral category was introduced by Walborn in 1972 to describe peculiar stars which possess intense emission lines of C III 4647,4650,4651. Recently, two of them, HD 108 and HD 191612, were ... [more ▼]

The Of?p spectral category was introduced by Walborn in 1972 to describe peculiar stars which possess intense emission lines of C III 4647,4650,4651. Recently, two of them, HD 108 and HD 191612, were found to display spectacular line profile variations in the visible domain: these stars apparently alternate between two different spectral states (O6-O8). To discover the origin of this intriguing behaviour, a multiwavelength campaign was undertaken. In this context, the analysis of the X-ray emission is especially important since it provides crucial information for constraining the nature of these peculiar objects and testing conflicting models. We are therefore carrying out high-quality XMM-Newton observations of these stars and we present the results of the data obtained up to now. [less ▲]

Detailed reference viewed: 4 (0 ULg)
Full Text
See detailAstrophysics, and how to attract young people into Physics
Nazé, Yaël ULg; Stavinschi, Magda; Vanherck, Martine ULg

Book (2005)

Detailed reference viewed: 23 (3 ULg)
Full Text
See detailMassive Stars and High-Energy Emission in OB Associations
Rauw, Grégor ULg; Nazé, Yaël ULg; Blomme, Ronny et al

Book (2005)

Detailed reference viewed: 3 (0 ULg)
See detailLes couleurs de l'Univers
Nazé, Yaël ULg

Book (2005)

à quoi ressemble la Voie lactée dans l'ultraviolet ? Que cachent les nuages de poussière qui voilent des parties entières du ciel ? Avec la découverte des ondes électromagnétiques (ondes radio ... [more ▼]

à quoi ressemble la Voie lactée dans l'ultraviolet ? Que cachent les nuages de poussière qui voilent des parties entières du ciel ? Avec la découverte des ondes électromagnétiques (ondes radio, ultraviolet, infrarouge, rayons X, gamma), le ciel s'est teinté de nouvelles couleurs, changeant totalement d'aspect, jusqu'à révéler des phénomènes d'une violence insoupçonnée. Les télescopes du monde entier obtiennent maintenant des images d'un univers inconnu que l'auteur nous apprend à comprendre. Riche en anecdotes parfois cocasses sur des découvertes qui doivent parfois au hasard ou Ãà la persévérance obstinée de chercheurs, le livre invite le lecteur à découvrir un monde invisible à l'oeil. Des mystérieux quasars au rayonnement cosmologique, c'est à un voyage au fil de ce nouvel arc-en-ciel que nous convie l'auteur. [less ▲]

Detailed reference viewed: 11 (1 ULg)
See detailVision cosmique: le futur de l'espace européen
Nazé, Yaël ULg

Article for general public (2005)

Detailed reference viewed: 1 (0 ULg)
See detailExobiologie et complexité
Javaux, Emmanuelle ULg; Nazé, Yaël ULg

Article for general public (2005)

Detailed reference viewed: 18 (5 ULg)
See detailAstrobiologie et exploration du système solaire
Javaux, Emmanuelle ULg; Lebreton, Jean-Pierre; Chicarro, Augustin et al

Conference given outside the academic context (2005)

Detailed reference viewed: 5 (2 ULg)
See detailNous avons lu pour vous
Nazé, Yaël ULg

Article for general public (2005)

La Voie Lactée, Chaberlot, F.

Detailed reference viewed: 10 (3 ULg)
Full Text
Peer Reviewed
See detailOptical spectroscopy of X-Mega targets - V. The spectroscopic binary HD 93161 A and its visual companion HD 93161 B
Nazé, Yaël ULg; Antokhin, I. I.; Sana, H. et al

in Monthly Notices of the Royal Astronomical Society (2005), 359(2), 688-698

We present the analysis of an extensive set of high-resolution spectroscopic observations of HD 93161, a visual binary with a separation of 2 arcsec. HD 93161 A is a spectroscopic binary, with both ... [more ▼]

We present the analysis of an extensive set of high-resolution spectroscopic observations of HD 93161, a visual binary with a separation of 2 arcsec. HD 93161 A is a spectroscopic binary, with both components clearly detected throughout the orbit. The primary star is most probably of spectral type O8V, while the secondary is likely an O9V. We obtain the first orbital solution for this system, characterized by a period of 8.566 +/- 0.004 d. The minimum masses of the primary and secondary stars are 22.2 +/- 0.6 and 17.0 +/- 0.4 M-., respectively. These values are quite large, suggesting a high inclination of the orbit. The second object, HD 93161 B, displays an O6.5V(f) spectral type and is thus slightly hotter than its neighbour. This star is at first sight single but presents radial velocity variations. Finally, we study HD 93161 in the X-ray domain. No significant variability is detected. The X-ray spectrum is well described by a 2T model with kT(1) similar to 0.3 keV and kT(2) similar to 0.7 keV. The X-ray luminosity is rather moderate, without any large emission excess imputable to a wind interaction. [less ▲]

Detailed reference viewed: 24 (3 ULg)
See detailSous le vent des étoiles massives
Nazé, Yaël ULg

Article for general public (2005)

Not Available

Detailed reference viewed: 5 (0 ULg)
See detailRendez-vous des mondes lointains
Nazé, Yaël ULg

Article for general public (2005)

Detailed reference viewed: 3 (0 ULg)
See detailA la recherche du neutrino perdu
Nazé, Yaël ULg

Article for general public (2005)

Detailed reference viewed: 4 (1 ULg)
Full Text
Peer Reviewed
See detailThe spectrum of the very massive binary system WR20a (WN6ha+WN6ha): Fundamental parameters and wind interactions
Rauw, Grégor ULg; Crowther, P. A.; De Becker, Michaël ULg et al

in Astronomy and Astrophysics (2005), 432(3), 985-998

We analyse the optical spectrum of the very massive binary system WR20a (WN6ha + WN6ha). The most prominent emission lines, Halpha and He II lambda4686, display strong phase-locked profile variability ... [more ▼]

We analyse the optical spectrum of the very massive binary system WR20a (WN6ha + WN6ha). The most prominent emission lines, Halpha and He II lambda4686, display strong phase-locked profile variability. From the variations of their equivalent widths and from a tomographic analysis, we find that part of the line emission probably arises in a wind interaction region between the stars. Our analysis of the optical spectrum of WR20a indicates a reddening of A(nu) similar or equal to 6.0 mag and a distance of similar to 7.9 kpc, suggesting that the star actually belongs to the open cluster Westerlund 2. The location of the system at similar to 1.1 pc from the cluster core could indicate that WR20a was gently ejected from the core via dynamical interactions. Using a non-LTE model atmosphere code, we derive the fundamental parameters of each component: T-eff = 43 000 +/- 2000 K, log L-bol/ L-. similar or equal to 6.0, (M) over dot = 8.5 x 10(-6) M-. yr(-1) (assuming a clumped wind with a volume filling factor f = 0.1). Nitrogen is enhanced in the atmospheres of the components of WR20a, while carbon is definitely depleted. Finally, the position of the binary components in the Hertzsprung-Russell diagram suggests that they are core hydrogen burning stars in a pre-LBV stage and their current atmospheric chemical composition probably results from rotational mixing that might be enhanced in a close binary compared to a single star of same age. [less ▲]

Detailed reference viewed: 21 (2 ULg)
See detailLes secrets du pendule
Nazé, Yaël ULg

Article for general public (2005)

Detailed reference viewed: 4 (0 ULg)
See detailBulles célestes
Nazé, Yaël ULg

Article for general public (2005)

See detailLes Belges vibrent pour les étoiles
Nazé, Yaël ULg

Article for general public (2005)

Detailed reference viewed: 2 (0 ULg)
Full Text
Peer Reviewed
See detailAn XMM-Newton look at the Wolf-Rayet star WR 40 - The star itself, its nebula and its neighbours
Gosset, Eric ULg; Nazé, Yaël ULg; Claeskens, Jean-François ULg et al

in Astronomy and Astrophysics (2005), 429(2), 685-704

We present the results of an XMM-Newton observation of the field of the Wolf-Rayet star WR 40. Despite a nominal exposure of 20 ks and the high sensitivity of the satellite, the star itself is not ... [more ▼]

We present the results of an XMM-Newton observation of the field of the Wolf-Rayet star WR 40. Despite a nominal exposure of 20 ks and the high sensitivity of the satellite, the star itself is not detected: we thus derive an upper limit on its X-ray flux and luminosity. Joining this result to recent reports of a non-detection of some WC stars, we suggest that the X-ray emission from single normal Wolf-Rayet stars could often be insignificant despite remarkable instabilities in the wind. On the basis of a simple modelling of the opacity of the Wolf-Rayet wind of WR 40, we show that any X-ray emission generated in the particular zone where the shocks are supposed to be numerous will indeed have little chance to emerge from the dense wind of the Wolf-Rayet star. We also report the non-detection of the ejecta nebula RCW 58 surrounding WR 40. Concerning the field around these objects, we detected 33 X-ray sources, most of them previously unknown: we establish a catalog of these sources and cross-correlate it with catalogs of optical/infrared sources. [less ▲]

Detailed reference viewed: 28 (8 ULg)
Full Text
See detailFrédéric Chaberlot, La Voie Lactée: histoire des conceptions et des modèles de notre Galaxie des temps anciens aux années 1930, Bibliographie critique
Nazé, Yaël ULg

in Archives Internationales d'Histoire des Sciences (2005), (154), 302-302

Detailed reference viewed: 23 (1 ULg)
See detailVibrato, ma non troppo.
Nazé, Yaël ULg

Article for general public (2005)

Not Available

Detailed reference viewed: 8 (1 ULg)