References of "Dupret, Marc-Antoine"      in Complete repository Arts & humanities   Archaeology   Art & art history   Classical & oriental studies   History   Languages & linguistics   Literature   Performing arts   Philosophy & ethics   Religion & theology   Multidisciplinary, general & others Business & economic sciences   Accounting & auditing   Production, distribution & supply chain management   Finance   General management & organizational theory   Human resources management   Management information systems   Marketing   Strategy & innovation   Quantitative methods in economics & management   General economics & history of economic thought   International economics   Macroeconomics & monetary economics   Microeconomics   Economic systems & public economics   Social economics   Special economic topics (health, labor, transportation…)   Multidisciplinary, general & others Engineering, computing & technology   Aerospace & aeronautics engineering   Architecture   Chemical engineering   Civil engineering   Computer science   Electrical & electronics engineering   Energy   Geological, petroleum & mining engineering   Materials science & engineering   Mechanical engineering   Multidisciplinary, general & others Human health sciences   Alternative medicine   Anesthesia & intensive care   Cardiovascular & respiratory systems   Dentistry & oral medicine   Dermatology   Endocrinology, metabolism & nutrition   Forensic medicine   Gastroenterology & hepatology   General & internal medicine   Geriatrics   Hematology   Immunology & infectious disease   Laboratory medicine & medical technology   Neurology   Oncology   Ophthalmology   Orthopedics, rehabilitation & sports medicine   Otolaryngology   Pediatrics   Pharmacy, pharmacology & toxicology   Psychiatry   Public health, health care sciences & services   Radiology, nuclear medicine & imaging   Reproductive medicine (gynecology, andrology, obstetrics)   Rheumatology   Surgery   Urology & nephrology   Multidisciplinary, general & others Law, criminology & political science   Civil law   Criminal law & procedure   Criminology   Economic & commercial law   European & international law   Judicial law   Metalaw, Roman law, history of law & comparative law   Political science, public administration & international relations   Public law   Social law   Tax law   Multidisciplinary, general & others Life sciences   Agriculture & agronomy   Anatomy (cytology, histology, embryology...) & physiology   Animal production & animal husbandry   Aquatic sciences & oceanology   Biochemistry, biophysics & molecular biology   Biotechnology   Entomology & pest control   Environmental sciences & ecology   Food science   Genetics & genetic processes   Microbiology   Phytobiology (plant sciences, forestry, mycology...)   Veterinary medicine & animal health   Zoology   Multidisciplinary, general & others Physical, chemical, mathematical & earth Sciences   Chemistry   Earth sciences & physical geography   Mathematics   Physics   Space science, astronomy & astrophysics   Multidisciplinary, general & others Social & behavioral sciences, psychology   Animal psychology, ethology & psychobiology   Anthropology   Communication & mass media   Education & instruction   Human geography & demography   Library & information sciences   Neurosciences & behavior   Regional & inter-regional studies   Social work & social policy   Sociology & social sciences   Social, industrial & organizational psychology   Theoretical & cognitive psychology   Treatment & clinical psychology   Multidisciplinary, general & others     Showing results 141 to 160 of 166     3 4 5 6 7 8 9     Non-adiabatic asteroseismology of near-main sequence variable starsDupret, Marc-Antoine in IAU Colloq. 193: Variable Stars in the Local Group (2004, May 01)We present in this talk a new linear non-adiabatic pulsation code: MAD[SUP]1[/SUP]. We detail all the possible applications of it in the frame of asteroseismology. By using it, photospheric observables ... [more ▼]We present in this talk a new linear non-adiabatic pulsation code: MAD[SUP]1[/SUP]. We detail all the possible applications of it in the frame of asteroseismology. By using it, photospheric observables such as multi-color photometric amplitude ratios, phase differences and line profile variations can be determined accurately and confronted with observations. Moreover, MAD enables the precisely analysis of the excitation mechanisms of pulsating stars. Applications to different kinds of variable stars (delta Sct, beta Cephei, Slowly Pulsating B and gamma Dor stars) are presented by Dupret et al. (these proceedings), Handler and Aerts (these proceedings), De Cat et al. (these proceedings) and De Ridder et al. (these proceedings). [less ▲]Detailed reference viewed: 7 (1 ULg) Nonadiabatic observables in main sequence delta Scuti starsMoya, A.; Garrido, R.; Dupret, Marc-Antoine in IAU Colloq. 193: Variable Stars in the Local Group (2004, May 01)Using a theoretical nonadiabatic pulsation model, phase differences and amplitude ratios between the relative effective temperature variation and the relative radial displacement have been calculated ... [more ▼]Using a theoretical nonadiabatic pulsation model, phase differences and amplitude ratios between the relative effective temperature variation and the relative radial displacement have been calculated. These quantities, when compared with photometric observations in different colors, provide an efficient instrument for mode identification, the first step to understand the internal structure of the stars. The theoretical results presented in this paper show a dependence for delta Scuti stars on the mixing length parameter alpha used to treat the convection using the standard Mixing Length Theory. The nonadiabatic pulsational code developed here includes the pulsation atmosphere interaction as described by Dupret et al. (2002). The equilibrium models are provided by the CESAM evolutionary code, where a complete reconstruction of non-grey atmospheres (Kurucz models) is included. [less ▲]Detailed reference viewed: 8 (1 ULg) Mode identification using photometry and spectroscopyDe Ridder, Joris; Aerts, Conny; Dupret, Marc-Antoine in IAU Colloq. 193: Variable Stars in the Local Group (2004, May 01)We tested a stepwise approach to combine photometry and spectroscopy for mode identificaiton where we first used the photometric amplitude ratios to restrict the degree l, then did a spectroscopic mode ... [more ▼]We tested a stepwise approach to combine photometry and spectroscopy for mode identificaiton where we first used the photometric amplitude ratios to restrict the degree l, then did a spectroscopic mode identification, and finally fitted the photometric amplitudes to restrict the list of candidate modes. For the spectroscopic mode identification, we implemented an efficient multi-mode moment method variant. We conclude that this new variant works well, but that the photometric amplitudes are too model sensitive to do any additional mode discrimination. [less ▲]Detailed reference viewed: 10 (1 ULg) Long-term multicolour photometry and high-resolution spectroscopy of the two gamma Doradus stars HD 12901 and HD 48501Aerts, C.; Cuypers, J.; De Cat, P. et alin Astronomy and Astrophysics (2004), 415We gathered long-term multicolour Geneva UB[SUB]1[/SUB]BB[SUB]2[/SUB]V[SUB]1[/SUB]VG photometric and high-resolution (R=40 000) spectroscopic data of the two gamma Doradus stars HD 12901 and HD 48501. The ... [more ▼]We gathered long-term multicolour Geneva UB[SUB]1[/SUB]BB[SUB]2[/SUB]V[SUB]1[/SUB]VG photometric and high-resolution (R=40 000) spectroscopic data of the two gamma Doradus stars HD 12901 and HD 48501. The photometry reveals three frequencies for each of the two stars: f[SUB]1[/SUB]=1.21563 c d[SUP]-1[/SUP], f[SUB]2[/SUB]=1.39594 c d[SUP]-1[/SUP] and f[SUB]3[/SUB]=2.18636 c d[SUP]-1[/SUP] for HD 12901 and f[SUB]1[/SUB]=1.09408 c d[SUP]-1[/SUP], f[SUB]2[/SUB]=1.29054 c d[SUP]-1[/SUP] and f[SUB]3[/SUB]=1.19924 c d[SUP]-1[/SUP] for HD 48501. The photometric amplitude is each time largest in the Geneva B[SUB]1[/SUB] filter and the variations in all the different filters are perfectly in phase within the measurement errors. Mode identification points out that the six modes are all l=1 modes and that the non-adiabatic temperature variations are extremely small, in contradiction to current theoretical predictions. Our spectra show that all the observed frequencies are intrinsic to the stars and cannot be due to binarity. We detect clear line-profile variations at low amplitude (<1 km s[SUP]-1[/SUP]) due to the oscillations of both targets. The estimated v sin i from the spectra are Ë 53 km s[SUP]-1[/SUP] for HD 12901 and Ë 29 km s[SUP]-1[/SUP] for HD 48501. It is at present unclear if the triplet-like structure for HD 48501 is the consequence of rotational splitting or of the large separation expected for high-order gravity modes in the asymptotic regime. Based on observations gathered with the Swiss 0.7 m telescope equipped with the photometer P 7 and with the Swiss 1.2 m Euler telescope equipped with the spectrograph CORALIE, both situated at La Silla, Chile. Reduced data available upon request from the first author. [less ▲]Detailed reference viewed: 5 (3 ULg) Non-adiabatic theoretical observables in delta Scuti starsMoya, A.; Garrido, R.; Dupret, Marc-Antoine in Astronomy and Astrophysics (2004), 414Phase differences and amplitude ratios at different colour photometric bands are currently being used to discriminate pulsation modes to facilitate mode identification of kappa-driven non-radial pulsating ... [more ▼]Phase differences and amplitude ratios at different colour photometric bands are currently being used to discriminate pulsation modes to facilitate mode identification of kappa-driven non-radial pulsating stars. In addition to physical inputs (e.g., mass, T_eff, etc.), these quantities depend on the non-adiabatic treatment of the atmosphere. This paper presents theoretical results concerning delta Scuti pulsating stars. The envelope of each of these stellar structures possesses a convection zone whose development is determined by various factors. An interacting pulsation-atmosphere physical treatment is introduced which supplies two basic non-adiabatic physical quantities: the relative effective temperature variation and the phase lag phi[SUP]T[/SUP], defined as the angle between effective temperature variation and radial displacement. These quantities can be used to derive the phase differences and amplitude ratios. Numerivalues for these quantities depend critically on the alpha MLT parameter used to calculate the convection in the envelope. The dependence on alpha was analyzed and it was found that the use of colour observations may be of considerable importance in testing the MLT. Finally, examples are given of how alpha introduces uncertainties in the theoretical predictions regarding phases and amplitudes of photometric variations in delta Scuti pulsating stars. [less ▲]Detailed reference viewed: 2 (0 ULg) Asteroseismology of the beta Cep star HD 129929. I. Observations, oscillation frequencies and stellar parametersAerts, C.; Waelkens, C.; Daszynska-Daszkiewicz, J. et alin Astronomy and Astrophysics (2004), 415We have gathered and analysed a timeseries of 1493 high-quality multicolour Geneva photometric data of the B3V beta Cep star HD 129929. The dataset has a time base of 21.2 years. The occurrence of a ... [more ▼]We have gathered and analysed a timeseries of 1493 high-quality multicolour Geneva photometric data of the B3V beta Cep star HD 129929. The dataset has a time base of 21.2 years. The occurrence of a beating phenomenon is evident from the data. We find evidence for the presence of at least six frequencies, among which we see components of two frequency multiplets with an average spacing of Ë 0.0121 c d[SUP]-1[/SUP] which points towards very slow rotation. This result is in agreement with new spectroscopic data of the star and also with previously taken UV spectra. We provide the amplitudes of the six frequencies in all seven photometric filters. The metal content of the star is Z=0.018± 0.004. All these observational results will be used to perform detailed seismic modelling of this massive star in a subsequent paper. Based on data gathered with the Swiss 0.7m telescope equipped with the photometer P7 of the Geneva Observatory and with the FEROS spectrograph attached to the ESO 2.2 m telescope, both situated at La Silla in Chile; the reduced photometric multicolour data are provided in Table 1, which is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/415/241 [less ▲]Detailed reference viewed: 7 (5 ULg) Asteroseismology of the beta Cep star HD 129929. II. Seismic constraints on core overshooting, internal rotation and stellar parametersDupret, Marc-Antoine ; Thoul, Anne ; Scuflaire, Richard et alin Astronomy and Astrophysics (2004), 415We perform a detailed seismic study of the beta Cep star HD 129929. Our analysis is based on the recent derivation of six pulsation frequencies. These frequencies are unambiguously identified from the ... [more ▼]We perform a detailed seismic study of the beta Cep star HD 129929. Our analysis is based on the recent derivation of six pulsation frequencies. These frequencies are unambiguously identified from the seismic modelling and the photometric amplitudes to be the radial fundamental, the l=1, p[SUB]1[/SUB] triplet, two consecutive components of the l=2, g[SUB]1[/SUB] quintuplet. A non-adiabatic analysis allows us to constrain the metallicity of the star to Z \in [0.016, 0.022]. In addition, the fitting of three independent frequencies, two of which correspond to axisymmetric (m=0) modes, allows us to constrain the core overshooting parameter to alpha[SUB]ov[/SUB]=0.10 ± 0.05, as well as the other global parameters of the star. Finally, from the observation of the l=1 triplet and part of the l=2 quintuplet, we derive constraints on the internal rotation of this star. [less ▲]Detailed reference viewed: 10 (5 ULg) Non-adiabatic pulsations in delta Scuti starsMoya, A.; Garrido, R.; Dupret, Marc-Antoine in Stellar Structure and Habitable Planet Finding (2004, January 01)For delta Scuti stars, phase differences and amplitude ratios between the relative effective temperature variation and the relative radial displacement can be derived from multicolor photometric ... [more ▼]For delta Scuti stars, phase differences and amplitude ratios between the relative effective temperature variation and the relative radial displacement can be derived from multicolor photometric observations. The same quantities can be also calculated from theoretical non-adiabatic pulsation models. We present here these theoretical results, which indicate that non-adiabatic quantities depend on the mixing length parameter alpha used to treat the convection in the standard Mixing Length Theory (MLT). This dependence can be used to test and to constrain, through multicolor observations, the way MLT describes convection in the outermost layers of the star. We will use the equilibrium models provided by the CESAM evolutionary code. The pulsational observables are calculated by using a non-adiabatic pulsation code developed by R. Garridon and A. Moya. In the evolutionary and pulsation codes, a complete reconstruction of the non-grey atmosphere (Kurucz models) is included. The interaction between pulsation and atmosphere, as described by Dupret et al. (2002), is also included in the code. [less ▲]Detailed reference viewed: 7 (1 ULg) Theoretical instability strips for delta Scuti and gamma Doradus starsDupret, Marc-Antoine ; Grigahcène, A.; Garrido, R. et alin Astronomy and Astrophysics (2004), 414New theoretical instability strips for delta Sct and gamma Dor stars are presented. These results have been obtained taking into account the perturbation of the convective flux following the treatment of ... [more ▼]New theoretical instability strips for delta Sct and gamma Dor stars are presented. These results have been obtained taking into account the perturbation of the convective flux following the treatment of Gabriel (\cite{Gabriel1996}). For the first time, the red edge of the delta Sct instability strip for non-radial modes is obtained. The influence of this time-dependent convection (TDC) on the driving of the gamma Dor gravity modes is investigated. The results obtained for different values of the mixing-length parameter alpha are compared for the gamma Dor models. A good agreement with observations is found for models with alpha between 1.8 and 2.0. [less ▲]Detailed reference viewed: 11 (2 ULg) Geneva photometry of HD 129929 (Aerts+, 2004)Aerts, C.; Waelkens, C.; Daszynska-Daszkiewicz, J. et alin SIMBAD (2003), 341We have gathered and analysed a timeseries of 1493 high-quality multicolour Geneva photometric data of the B3V {beta} Cep star Hd 129929. The dataset has a time base of 21.2 years. The occurrence of a ... [more ▼]We have gathered and analysed a timeseries of 1493 high-quality multicolour Geneva photometric data of the B3V {beta} Cep star Hd 129929. The dataset has a time base of 21.2 years. The occurrence of a beating phenomenon is evident from the data. We find evidence for the presence of at least six frequencies, among which we see components of two frequency multiplets with an average spacing of ~0.0121c/d which points towards very slow rotation. This result is in agreement with new spectroscopic data of the star and also with previously taken UV spectra. We provide the amplitudes of the six frequencies in all seven photometric filters. The metal content of the star is Z=0.018+/-0.004. All these observational results will be used to perform detailed seismic modelling of this massive star in a subsequent paper. (1 data file). [less ▲]Detailed reference viewed: 7 (1 ULg) Seismic modelling of the beta Cep star EN (16) LacertaeThoul, Anne ; Aerts, C.; Dupret, Marc-Antoine et alin Astronomy and Astrophysics (2003), 406(1), 287-292We perform seismic modelling of the massive beta Cep star EN Lacertae. The starting point of our analysis is the spectroscopic mode identification recently performed. To this, we add a new updated ... [more ▼]We perform seismic modelling of the massive beta Cep star EN Lacertae. The starting point of our analysis is the spectroscopic mode identification recently performed. To this, we add a new updated photometric mode identification based upon a non-adiabatic description of the eigenfunctions in the outer atmosphere. Both mode identifications agree and this allows us to fine-tune the stellar parameters of EN Lacertae with unprecedented precision. This is done by producing a huge amount of stellar models with different parameters and selecting those that fulfill the frequency values and the mode identification. Our study is the first one of its kind in which a reconcilation between observed pulsational characteristics and theoretical models can be achieved at a level that allows accurate determination of the basic stellar parameters of a massive oscillator. We derive a mass of M=9.62+/- 0.11 M[SUB]sun[/SUB] and an age of 15.7 million years if we assume that convective overshooting does not occur. [less ▲]Detailed reference viewed: 13 (5 ULg) A Hare and Hound in a BAG: Asteroseismology of Beta Cephei starsThoul, Anne ; Ausseloos, M.; Barban, C. et alin Communications in Asteroseismology (2003), 143Several members of the COROT Seismology Working Group (SWG) have performed several hare-and-hound'' exercises to prepare the data exploitation of the mission in the past few years. These exercises ... [more ▼]Several members of the COROT Seismology Working Group (SWG) have performed several hare-and-hound'' exercises to prepare the data exploitation of the mission in the past few years. These exercises consist in reproducing a theoretical model on the basis of a light curve obtained from a frequency spectrum computed from an unknown'' theoretical model of a solar-like or a Delta Scuti star. Members of the BAG (Belgian Asteroseismology Group) have now shown that such an exercise in the mass range of Beta Cephei stars is extremely convincing, making these stars excellent targets for asteroseismology space missions. [less ▲]Detailed reference viewed: 10 (6 ULg) Asteroseismology of HD 129929: Core Overshooting and Nonrigid RotationAerts, C.; Thoul, Anne ; Daszynska, J. et alin Science (2003), 300We have gathered and analyzed 1493 high-quality multicolor Geneva photometric data taken over 21 years of the B3V star HD 129929. We detect six frequencies, among which appear the effects of rotational ... [more ▼]We have gathered and analyzed 1493 high-quality multicolor Geneva photometric data taken over 21 years of the B3V star HD 129929. We detect six frequencies, among which appear the effects of rotational splitting with a spacing of ~0.0121 cycles per day, which implies that the star rotates very slowly. A nonadiabatic analysis of the oscillations allows us to constrain the metallicity of the star to Z â [0.017,0.022], which agrees with a similar range derived from spectroscopic data. We provide evidence for the occurrence of core convective overshooting in the star, with alpha[SUB]ov[/SUB] = 0.10 +/- 0.05, and we rule out rigid rotation. [less ▲]Detailed reference viewed: 8 (6 ULg) A new seismic analysis of Alpha CentauriThoul, Anne ; Scuflaire, Richard ; Noels-Grötsch, Arlette et alin Astronomy and Astrophysics (2003), 402(1), 293-297Models of alpha Cen A & B have been computed using the masses determined by Pourbaix et al. (\cite{Po2002}) and the data derived from the spectroscopic analysis of Neuforge & Magain (\cite{Ne1997}). The ... [more ▼]Models of alpha Cen A & B have been computed using the masses determined by Pourbaix et al. (\cite{Po2002}) and the data derived from the spectroscopic analysis of Neuforge & Magain (\cite{Ne1997}). The seismological data obtained by Bouchy & Carrier (\cite{Bo2001}, \cite{Bo2002}) do help improve our knowledge of the evolutionary status of the system. All the constraints are satisfied with a model which gives an age of about 6 Gyr for the binary. [less ▲]Detailed reference viewed: 10 (4 ULg) Spectroscopic mode identification for the beta Cephei star EN (16) LacertaeAerts, C.; Lehmann, H.; Briquet, Maryline et alin Astronomy and Astrophysics (2003), 399We perform for the first time spectroscopic mode identification in the eclipsing binary beta Cephei star EN (16) Lac. This mode identification is based upon a time series of 942 line profiles of the He I ... [more ▼]We perform for the first time spectroscopic mode identification in the eclipsing binary beta Cephei star EN (16) Lac. This mode identification is based upon a time series of 942 line profiles of the He I lambda lambda 6678 Åline in its spectrum. All three known frequencies f[SUB]1[/SUB], f,SUB>2,/SUB>, f[SUB]3[/SUB] of the star are present in the line-profile variations, but we failed to find additional modes. Using different identification methods we find conclusive evidence for the radial nature of the main mode and for the l=2, m=0 identification of the mode with frequency f[SUB]2[/SUB]. A unique identification of the third mode is not possible from the spectra, but we do derive that l[SUB]3[/SUB]<3. Fits to the amplitude and phase variability of the modes imply a rotation frequency between 0.1 and 0.4 c d[SUP]-1[/SUP]. The star's rotation axis is not aligned with the orbital axis. Based on observations gathered with the coudé spectrograph attached to the 2.0 m reflector telescope at Tautenburg Observatory. [less ▲]Detailed reference viewed: 5 (4 ULg) A photometric mode identification method, including an improved non-adiabatic treatment of the atmosphereDupret, Marc-Antoine ; De Ridder, J.; De Cat, P. et alin Astronomy and Astrophysics (2003), 398We present an improved version of the method of photometric mode identification of Heynderickx et al. (\cite{hey}). Our new version is based on the inclusion of precise non-adiabatic eigenfunctions ... [more ▼]We present an improved version of the method of photometric mode identification of Heynderickx et al. (\cite{hey}). Our new version is based on the inclusion of precise non-adiabatic eigenfunctions determined in the outer stellar atmosphere according to the formalism recently proposed by Dupret et al. (\cite{dup}). Our improved photometric mode identification technique is therefore no longer dependent on ad hoc parameters for the non-adiabatic effects. It contains the complete physical conditions of the outer atmosphere of the star, provided that rotation does not play a key role. We apply our method to the two slowly pulsating B stars HD 74560 and HD 138764 and to the beta Cephei star EN (16) Lac. Besides identifying the degree l of the pulsating stars, our method is also a tool for improving the knowledge of stellar interiors and atmospheres, by imposing constraints on parameters such as the metallicity and the mixing-length parameter alpha (a procedure we label non-adiabatic asteroseismology). The non-adiabatic eigenfunctions needed for the mode identification are available upon request from the authors. [less ▲]Detailed reference viewed: 5 (5 ULg) p-mode Oscillations of alpha Cen AThoul, Anne ; Scuflaire, Richard ; Vatovez, B. et alin Astrophysics & Space Science (2003), 284Models of alpha Cen A & B have been computed using the masses determined by Pourbaix et al. (2002) and the data derived from the spectroscopic analysis of Neuforge and Magain (1997). The seismological ... [more ▼]Models of alpha Cen A & B have been computed using the masses determined by Pourbaix et al. (2002) and the data derived from the spectroscopic analysis of Neuforge and Magain (1997). The seismological data obtained by Bouchy and Carrier (2001, 2002) do help improve our knowledge of the evolutionary status of the system. All the constraints are satisfied with a model which gives an age of about 6 Gyr for the binary. [less ▲]Detailed reference viewed: 18 (5 ULg) Mode Identification and Seismic Modelling of the Cep Star EN(16)LacAerts, C.; Lehmann, H.; Scuflaire, Richard et alin Asteroseismology Across the HR Diagram (2003)Not AvailableDetailed reference viewed: 7 (5 ULg) Non-adiabatic Pulsational Observables in Scuti and Doradus Stars: a Comparison of Different Numerical CodesMoya, A.; Garrido, R.; Dupret, Marc-Antoine in Asteroseismology Across the HR Diagram (2003)Not AvailableDetailed reference viewed: 5 (1 ULg) Photometric Mode Identification in the Two Doradus Stars HD 12901 and HD 48501Aerts, C.; Cuypers, J.; Dupret, Marc-Antoine et alin Asteroseismology Across the HR Diagram (2003)Not AvailableDetailed reference viewed: 5 (1 ULg)