References of "2010"
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See detailCSR Performance Measurements: Motivations, Tools and Survey Results
Crutzen, Nathalie ULg

Scientific conference (2010, December 02)

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See detailLes règles d’interprétation en droit fiscal à la lumière de la jurisprudence des juridictions supérieures
Bourgeois, Marc ULg; Peeters, Bruno

Scientific conference (2010, December 02)

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See detailSpin-orbit angle measurements for six southern transiting planets. New insights into the dynamical origins of hot Jupiters
Triaud, A H M J; Collier Cameron, A.; Queloz, D. et al

in Astronomy and Astrophysics (2010), 524

Context. Several competing scenarios for planetary-system formation and evolution seek to explain how hot Jupiters came to be so close to their parent stars. Most planetary parameters evolve with time ... [more ▼]

Context. Several competing scenarios for planetary-system formation and evolution seek to explain how hot Jupiters came to be so close to their parent stars. Most planetary parameters evolve with time, making it hard to distinguish between models. The obliquity of an orbit with respect to the stellar rotation axis is thought to be more stable than other parameters such as eccentricity. Most planets, to date, appear aligned with the stellar rotation axis; the few misaligned planets so far detected are massive (> 2 M[SUB]J[/SUB]). <BR /> Aims: Our goal is to measure the degree of alignment between planetary orbits and stellar spin axes, to search for potential correlations with eccentricity or other planetary parameters and to measure long term radial velocity variability indicating the presence of other bodies in the system. <BR /> Methods: For transiting planets, the Rossiter-McLaughlin effect allows the measurement of the sky-projected angle β between the stellar rotation axis and a planet's orbital axis. Using the HARPS spectrograph, we observed the Rossiter-McLaughlin effect for six transiting hot Jupiters found by the WASP consortium. We combine these with long term radial velocity measurements obtained with CORALIE. We used a combined analysis of photometry and radial velocities, fitting model parameters with the Markov Chain Monte Carlo method. After obtaining β we attempt to statistically determine the distribution of the real spin-orbit angle ψ. <BR /> Results: We found that three of our targets have β above 90°: WASP-2b: β = 153°[SUP]+11[/SUP][SUB]-15[/SUB], WASP-15b: β = 139.6°[SUP]+5.2[/SUP][SUB]-4.3[/SUB] and WASP-17b: β = 148.5°[SUP]+5.1[/SUP][SUB]-4.2[/SUB]; the other three (WASP-4b, WASP-5b and WASP-18b) have angles compatible with 0°. We find no dependence between the misaligned angle and planet mass nor with any other planetary parameter. All six orbits are close to circular, with only one firm detection of eccentricity e = 0.00848[SUP]+0.00085[/SUP][SUB]-0.00095[/SUB] in WASP-18b. No long-term radial acceleration was detected for any of the targets. Combining all previous 20 measurements of β and our six and transforming them into a distribution of ψ we find that between about 45 and 85% of hot Jupiters have ψ > 30°. <BR /> Conclusions: Most hot Jupiters are misaligned, with a large variety of spin-orbit angles. We find observations and predictions using the Kozai mechanism match well. If these observational facts are confirmed in the future, we may then conclude that most hot Jupiters are formed from a dynamical and tidal origin without the necessity to use type I or II migration. At present, standard disc migration cannot explain the observations without invoking at least another additional process. Using observations with the high resolution échelle spectrograph HARPS mounted on the ESO 3.6 m (under proposals 072.C-0488, 082.C-0040 & 283.C-5017), and with the high resolution échelle spectrograph CORALIE on the 1.2 m Euler Swiss Telescope, both installed at the ESO La Silla Observatory in Chile.RV data is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/524/A25">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/524/A25</A> [less ▲]

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See detailPlasma Motion and Kinematics in Cool and Hot Stars
Güdel, Manuel; Nazé, Yaël ULg

in Space Science Reviews (2010), 157

The environments of both hot and cool stars are the sites of highly dynamic processes involving motion of gas and plasma in winds, flows across shocks, plasma motions in closed magnetic fields, or streams ... [more ▼]

The environments of both hot and cool stars are the sites of highly dynamic processes involving motion of gas and plasma in winds, flows across shocks, plasma motions in closed magnetic fields, or streams along magnetospheric accretion funnels. X-ray spectroscopy has opened new windows toward the study of these processes. Kinematics are evident in line shifts and line broadening, and also more indirectly through the analysis and interpretation of density-sensitive lines. In hot stellar winds, expanding-wind kinematics are directly seen in broadened lines although the broadening has turned out to often be smaller than anticipated, and some lines are so narrow that coronal models have been revived. Although X-ray spectra of cool stars have shown line shifts and broadening due to the kinematics of the entire corona, e.g., in binary systems, intrinsic mass motions are challenging to observe at the presently available resolution. Much indirect evidence for mass motion in magnetic coronae is nevertheless available. And finally, spectral diagnostics has also led to a new picture of X-ray production in accreting pre-main sequence stars where massive accretion flows collide with the photospheric gas, producing shocks in which gas is heated to high temperatures. We summarize evidence for the above mechanisms based on spectroscopic data from XMM-Newton and Chandra. [less ▲]

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See detailHard X-ray identification of η Carinae and steadiness close to periastron
Leyder, Jean-Christophe ULg; Walter, R.; Rauw, Grégor ULg

in Astronomy and Astrophysics (2010), 524

Context. The colliding-wind binary η Carinae exhibits soft X-ray thermal emission that varies strongly around the periastron passage. It has been found to have non-thermal emission, thanks to its ... [more ▼]

Context. The colliding-wind binary η Carinae exhibits soft X-ray thermal emission that varies strongly around the periastron passage. It has been found to have non-thermal emission, thanks to its detection in hard X-rays using INTEGRAL and Suzaku, and also in γ-rays with AGILE and Fermi. <BR /> Aims: This paper attempts to definitively identify η Carinae as the source of the hard X-ray emission, to examine how changes in the 2-10 keV band influence changes in the hard X-ray band, and to understand more clearly the mechanisms producing the non-thermal emission using new INTEGRAL observations obtained close to periastron passage. <BR /> Methods: To strengthen the identification of η Carinae with the hard X-ray source, a long Chandra observation encompassing the INTEGRAL/ISGRI error circle was analysed, and all other soft X-ray sources (including the outer shell of η Carinae itself) were discarded as likely counter-parts. To expand the knowledge of the physical processes governing the X-ray lightcurve, new hard X-ray images of η Carinae were studied close to periastron, and compared to previous observations far from periastron. <BR /> Results: The INTEGRAL component, when represented by a power law (with a photon index Γ of 1.8), would produce more emission in the Chandra band than observed from any point source in the ISGRI error circle apart from η Carinae, as long as the hydrogen column density to the ISGRI source is lower than N[SUB]H[/SUB] ≲ 10[SUP]24[/SUP] cm[SUP]-2[/SUP]. Sources with such a high absorption are very rare, thus the hard X-ray emission is very likely to be associated with η Carinae. The eventual contribution of the outer shell to the non-thermal component also remains fairly limited. Close to periastron passage, a 3-σ detection is achieved for the hard X-ray emission of η Carinae, with a flux similar to the average value far from periastron. <BR /> Conclusions: Assuming a single absorption component for both the thermal and non-thermal sources, this 3-σ detection can be explained with a hydrogen column density that does not exceed N[SUB]H[/SUB] ≲ 6 × 10[SUP]23[/SUP] cm[SUP]-2[/SUP] without resorting to an intrinsic increase in the hard X-ray emission. The energy injected in hard X-rays (averaged over a month timescale) appears to be rather constant at least as close as a few stellar radii, well within the acceleration region of the wind. [less ▲]

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See detailBlood Flow under External Strains; Phenomenological Approach, Theoretical Developments & Numerical Analysis
Paulus, Raphaël ULg; Erpicum, Sébastien ULg; Dewals, Benjamin ULg et al

in International Journal of Design & Nature and Ecodynamics (2010), 78

In the medical field, the measurement of blood flow characteristics is often necessary. More specifically, blood pressure is an essential measure when it comes to assessing health. All over the world ... [more ▼]

In the medical field, the measurement of blood flow characteristics is often necessary. More specifically, blood pressure is an essential measure when it comes to assessing health. All over the world, many people suffer from hyper- or hypotension, and as it is known that these diseases can lead to serious complications, it is of great interest to determine the blood pressure with high accuracy. Nowadays, such information requires the use of specifi c materials; the present method for the measurement of the arterial pressure, by applying pressure using an armband (with a control device called sphygmomanometer), is known to introduce significant errors due to the inadequacy of the band dimensions (both the length and the circumference). The objective of the present research is to study and simulate the discharge of the blood in an artery subjected to external strains using theoretical developments and a numerical approach. Based on these modelling results, the response of the fluid to the external pressure of the band can be studied, and fi nally appropriate corrective factors for the true pressure and the measured pressure could be assessed. This research has been carried out with the aim of sharing medical and engineering views on the subject. The artery can be modelled as a deformable pipe, where the blood fl owing in it is a fl uid with specifi c properties. Thus, two complementary and interconnected domains are covered, solid mechanics (to obtain analytic relations between the strains and the deformations, using either linear or non-linear theories) and fluid mechanics (to study the discharge of blood in a deformable pipe, using finite volume methods), therefore considering the problem as a loose fl uid–structure interaction (FSI). These two domains, which are well studied for common materials in civil engineering applications, are applied here not only to specifi c materials but especially to uncommon structures that, besides the somehow common FSI developments, lead to the investigation and research of very specifi c boundary conditions, giving them a physically based behaviour. At present, the research has reached the penultimate step, with the two main mentioned axes being fully developed and tested on their own. In particular, the boundary conditions developed for the models have been investigated and modelled in depth. [less ▲]

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See detailAsteroseismology of solar-type stars with Kepler: III. Ground-based data
Molenda-Żakowicz, J.; Bruntt, H.; Sousa, S. et al

in Astronomische Nachrichten (2010), 331

We report on the ground-based follow-up program of spectroscopic and photometric observations of solar-like asteroseismic targets for the Kepler space mission. These stars constitute a large group of more ... [more ▼]

We report on the ground-based follow-up program of spectroscopic and photometric observations of solar-like asteroseismic targets for the Kepler space mission. These stars constitute a large group of more than a thousand objects which are the subject of an intensive study by the Kepler Asteroseismic Science Consortium Working Group 1 (KASC WG-1). In the current work we will discuss the methods we use to determine the fundamental stellar atmospheric parameters using high-quality stellar spectra. These provide essential constraints for the asteroseismic modelling and make it possible to verify the parameters in the Kepler Input Catalogue (KIC). [less ▲]

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See detailLong-term magnetic field monitoring of the sun-like star ξ Bootis A
Morgenthaler, A.; Petit, P.; Aurière, M. et al

in Boissier, S.; Heydari-Malayeri, M.; Samadi, R. (Eds.) et al SF2A-2010: Proceedings of the Annual meeting of the French Society of Astronomy and Astrophysics (2010, December 01)

Phase-resolved observations of the solar-type star ξ Bootis A were obtained using the Narval spectropolarimeter at Telescope Bernard Lyot (Pic du Midi, France) during years 2007, 2008, 2009 and 2010. The ... [more ▼]

Phase-resolved observations of the solar-type star ξ Bootis A were obtained using the Narval spectropolarimeter at Telescope Bernard Lyot (Pic du Midi, France) during years 2007, 2008, 2009 and 2010. The data sets enable us to study both the rotational and the long-term evolution of various activity tracers. Here, we focus on the large-scale photospheric magnetic field (reconstructed by Zeeman-Doppler Imaging), the Zeeman broadening of the FeI 846.84 nm magnetic line, and the chromospheric CaII H and Hα emission. [less ▲]

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See detailTowards ensemble asteroseismology of the young open clusters χ Persei and NGC 6910
Saesen, S.; Pigulski, A.; Carrier, F. et al

in Astronomische Nachrichten (2010), 331

As a result of the variability survey in χ Persei and NGC 6910, the number of β Cep stars that are members of these two open clusters is increased to twenty stars, nine in NGC 6910 and eleven in χ Persei ... [more ▼]

As a result of the variability survey in χ Persei and NGC 6910, the number of β Cep stars that are members of these two open clusters is increased to twenty stars, nine in NGC 6910 and eleven in χ Persei. We compare pulsational properties, in particular the frequency spectra, of β Cep stars in both clusters and explain the differences in terms of the global parameters of the clusters. We also indicate that the more complicated pattern of the variability among B-type stars in χ Persei is very likely caused by higher rotational velocities of stars in this cluster. We conclude that the sample of pulsating stars in the two open clusters constitutes a very good starting point for the ensemble asteroseismology of β Cep-type stars and maybe also for other B-type pulsators. [less ▲]

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See detailGround-based follow-up in relation to Kepler asteroseismic investigation
Uytterhoeven, K.; Briquet, Maryline ULg; Bruntt, H. et al

in Astronomische Nachrichten (2010), 331

The Kepler space mission, successfully launched in March 2009, is providing continuous and high-precision photometry of thousands of stars simultaneously. The uninterrupted time-series of stars of all ... [more ▼]

The Kepler space mission, successfully launched in March 2009, is providing continuous and high-precision photometry of thousands of stars simultaneously. The uninterrupted time-series of stars of all known pulsation types are a precious source for asteroseismic studies. The Kepler data do not provide information on the physical parameters, such as T_eff, log g, metallicity, and v sin i, which are crucial for successful asteroseismic modelling. Additional ground-based time-series data are needed to characterize mode parameters in several types of pulsating stars. Therefore, ground-based multi-colour photometry and mid/high-resolution spectroscopy are needed to complement the space data. We present ground-based activities within KASC on selected asteroseismic Kepler targets of several pulsation types. Based on observations made with the Isaac Newton Telescope and William Herschel Telescope operated by the Isaac Newton Group, with the Nordic Optical Telescope, operated jointly by Denmark, Finland, Iceland, Norway, and Sweden, with the Italian Telescopio Nazionale Galileo (TNG) operated by the Fundación Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica), and with the Mercator telescope, operated by the Flemish Community, all on the island of La Palma at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias (IAC). Based on observations made with the IAC-80 operated on the island of Tenerife by the IAC at the Spanish Observatorio del Teide. Also based on observations taken at the observatories of Sierra Nevada, San Pedro Mártir, Vienna, Xinglong, Apache Point, Lulin, Tautenburg, McDonald, Skinakas, Pic du Midi, Mauna Kea, Steward Observatory, Mt. Wilson, Białków Observatory of the Wrocław University, Piszkésteto Mountain Station, and Observatoire de Haute Provence. Based on spectra taken at the Loiano (INAF - OA Bologna), Serra La Nave (INAF - OA Catania) and Asiago (INAF - OA Padova) observatories. Also based on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck-Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC). We acknowledge with thanks the variable star observations from the AAVSO International Database contributed by observers worldwide and used in this research. Funding for the Kepler mission is provided by NASA's Science Mission Directorate. We thank the entire Kepler team for the development and operations of this outstanding mission. [less ▲]

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See detailComet 103P/Hartley
Jehin, Emmanuel ULg; Manfroid, Jean ULg; Hutsemekers, Damien ULg et al

in Central Bureau Electronic Telegrams (CBETs) (2010), 2589

CBET 2589 available at Central Bureau for Astronomical Telegrams.

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See detailWASP-22 b: A Transiting "Hot Jupiter" Planet in a Hierarchical Triple System
Maxted, P. F. L.; Anderson, D. R.; Gillon, Michaël ULg et al

in Astrophysical Journal (2010), 140(6), 2007-2012

We report the discovery of a transiting planet orbiting the star TYC 6446-326-1. The star, WASP-22, is a moderately bright (V = 12.0) solar-type star (T[SUB]eff[/SUB] = 6000 ± 100 K, [Fe/H] = –0.05 ± 0.08 ... [more ▼]

We report the discovery of a transiting planet orbiting the star TYC 6446-326-1. The star, WASP-22, is a moderately bright (V = 12.0) solar-type star (T[SUB]eff[/SUB] = 6000 ± 100 K, [Fe/H] = –0.05 ± 0.08). The light curve of the star obtained with the WASP-South instrument shows periodic transit-like features with a depth of about 1% and a duration of 0.14 days. The presence of a transit-like feature in the light curve is confirmed using z-band photometry obtained with Faulkes Telescope South. High-resolution spectroscopy obtained with the CORALIE and HARPS spectrographs confirms the presence of a planetary mass companion with an orbital period of 3.533 days in a near-circular orbit. From a combined analysis of the spectroscopic and photometric data assuming that the star is a typical main-sequence star we estimate that the planet has a mass M [SUB]p[/SUB] = 0.56 ± 0.02M [SUB]Jup[/SUB] and a radius R [SUB]p[/SUB] = 1.12 ± 0.04R [SUB]Jup[/SUB]. In addition, there is a linear trend of 40 m s[SUP]–1[/SUP] yr[SUP]–1[/SUP] in the radial velocities measured over 16 months, from which we infer the presence of a third body with a long-period orbit in this system. The companion may be a low mass M-dwarf, a white dwarf, or a second planet. [less ▲]

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See detail"Politique linguistique et organisation des centres de langues dans les universités"
Defays, Jean-Marc ULg

Scientific conference (2010, December 01)

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See detailInference from adiabatic analysis of solar-like oscillations in red giants
Montalban Iglesias, Josefa ULg; Miglio, Andrea ULg; Noels-Grötsch, Arlette ULg et al

in Astronomische Nachrichten (2010), 331

The clear detection with CoRoT and Kepler of radial and non-radial solar-like oscillations in many red giants paves the way to seismic inferences on the structure of such stars. We present an overview of ... [more ▼]

The clear detection with CoRoT and Kepler of radial and non-radial solar-like oscillations in many red giants paves the way to seismic inferences on the structure of such stars. We present an overview of the properties of the adiabatic frequencies and frequency separations of radial and non-radial oscillation modes, highlighting how their detection allows a deeper insight into the properties of the internal structure of red giants. In our study we consider models of red giants in different evolutionary stages, as well as of different masses and chemical composition. We describe how the large and small separations computed with radial modes and with non-radial modes mostly trapped in the envelope depend on the stellar global parameters and evolutionary state, and we compare our theoretical predictions and first Kepler data.Finally, we find that the properties of dipole modes constitute a promising seismic diagnostic of the evolutionary state of red-giant stars. [less ▲]

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See detailDe la participation au projet à l’implication dans le territoire
Dawance, Sophie ULg; Ribeiro Amélia, De Rijck Kim

Scientific conference (2010, December 01)

Nul ne nie aujourd’hui l’intérêt d’associer les habitants et usagers au processus d’élaboration d’un projet de rénovation de leur quartier. Cependant, force est de constater que les délais et modalités de ... [more ▼]

Nul ne nie aujourd’hui l’intérêt d’associer les habitants et usagers au processus d’élaboration d’un projet de rénovation de leur quartier. Cependant, force est de constater que les délais et modalités de la participation classique ne permettent pas à certains types de public de s’exprimer et ne laissent pas le temps de la maturation et de l’appropriation. Il faut donc inventer des formes d’intervention qui permettent l’implication des habitants dans la ville dans la durée et qui participent à l’émergence d’une véritable culture de la participation. Community land trust, potager collectif, urbanisme temporaire, budgets participatifs… autant de projets qui permettent aux citoyens de devenir acteur et de tisser des liens intimes avec leur territoire. [less ▲]

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See detailAsteroseismology of OB stars with CoRoT
Degroote, P.; Aerts, C.; Samadi, R. et al

in Astronomische Nachrichten (2010), 331

The CoRoT satellite is revolutionizing the photometric study of massive O-type and B-type stars. During its long runs, CoRoT observed the entire main sequence B star domain, from typical hot β Cep stars ... [more ▼]

The CoRoT satellite is revolutionizing the photometric study of massive O-type and B-type stars. During its long runs, CoRoT observed the entire main sequence B star domain, from typical hot β Cep stars, via cooler hybrid p- and g-mode pulsators to the SPB stars near the edge of the instability strip. CoRoT lowers the sensitivity barrier from the typical mmag-precision reached from the ground, to the μmag-level reached from space. Within the wealth of detected and identified pulsation modes, relations have been found in the form of multiplets, combination of frequencies, and frequency- and period spacings. This wealth of observational evidence is finally providing strong constraints to test current models of the internal structure and pulsations of hot stars. Aside from the expected opacity driven modes with infinite lifetime, other unexpected types of variability are detected in massive stars, such as modes of stochastic nature. The simultaneous observation of all these light curve characteristics implies a challenge for both observational asteroseismology and stellar modelling. The CoRoT space mission was developed and is operated by the French space agency CNES, with participation of ESA's RSSD and Science Programmes, Austria, Belgium, Brazil, Germany, and Spain. [less ▲]

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See detailOscillations in rapidly rotating stars
Reese, Daniel ULg

in Astronomische Nachrichten (2010, December 01), 331

Spurred by the spectroscopic and interferometric observations of rapidly rotating stars and the highly accurate pulsation data coming from asteroseismology space missions, theoreticians have spent many ... [more ▼]

Spurred by the spectroscopic and interferometric observations of rapidly rotating stars and the highly accurate pulsation data coming from asteroseismology space missions, theoreticians have spent many years developing models for such stars and studying their oscillations. This has led to the discovery of new phenomena and new types of pulsation modes. In what follows, a review is given of the different methods used to model the effects of rotation on stellar pulsations, as well as a description of these effects on inertial, gravito-inertial, r and acoustic modes. [less ▲]