A5006206971- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astrophysical Phenomena and Observations
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- High-pressure geophysics and materials
- Solar and Space Plasma Dynamics
- History and Developments in Astronomy
- Particle Detector Development and Performance
- Superconducting and THz Device Technology
- Calibration and Measurement Techniques
- Adaptive optics and wavefront sensing
- Pulsars and Gravitational Waves Research
- Galaxies: Formation, Evolution, Phenomena
- Superconducting Materials and Applications
- Atmospheric Ozone and Climate
- Geophysics and Gravity Measurements
- Spacecraft and Cryogenic Technologies
- Atomic and Molecular Physics
- Ionosphere and magnetosphere dynamics
- Molecular spectroscopy and chirality
- Advanced Measurement and Metrology Techniques
University of Liège
2015-2024
Fund for Scientific Research
1999-2020
Centre National d'Études Spatiales
2020
Institut d'Astrophysique Spatiale
2017-2019
University of Palermo
2018
University of Nova Gorica
2018
Laboratoire de Physique Nucléaire et de Hautes Énergies
2001-2017
SRON Netherlands Institute for Space Research
2012
Laboratoire d’Études en Géophysique et Océanographie Spatiales
1998-2009
Instituto Argentino de Radioastronomía
2009
The X-ray Integral Field Unit (X-IFU) is the high resolution spectrometer of ESA Athena observatory. Over a field view 5' equivalent diameter, it will deliver spectra from 0.2 to 12 keV with spectral 2.5 eV up 7 on ∼ 5" pixels. X-IFU based large format array super-conducting molybdenum-gold Transition Edge Sensors cooled at 90 mK, each coupled an absorber made gold and bismuth pitch 249 μm. A cryogenic anti-coincidence detector located underneath prime TES enables non background be reduced....
MESS (Mass-loss of Evolved StarS) is a Guaranteed Time Key Program that uses the PACS and SPIRE instruments on board Herschel Space Observatory to observe representative sample evolved stars, include asymptotic giant branch (AGB) post-AGB planetary nebulae red supergiants, as well luminous blue variables, Wolf-Rayet stars supernova remnants. In total, order 150 objects are observed in imaging about 50 spectroscopy. This paper describes target selection list, observing strategy. science...
The X-ray Integral Field Unit (X-IFU) on board the Advanced Telescope for High-ENergy Astrophysics (Athena) will provide spatially resolved high-resolution spectroscopy from 0.2 to 12 keV, with 5 arc second pixels over a field of view minute equivalent diameter and spectral resolution 2.5 eV up 7 keV. In this paper, we first review core scientific objectives Athena, driving main performance parameters X-IFU, namely resolution, view, effective area, count rate capabilities, instrumental...
We present the first high resolution X-ray spectrum of bright O4Ief supergiant star ζ Puppis, obtained with Reflection Grating Spectrometer on-board XMM-Newton. The exhibits emission lines hydrogen-like and helium-like ions nitrogen, oxygen, neon, magnesium, silicon, as well neon-like iron. are all significantly resolved, characteristic velocity widths order 1000-1500 km s-1. nitrogen especially strong, indicate that shocked gas in wind is mixed CNO-burned material, has been previously...
In this second paper, we pursue the analysis of 180 ks XMM-Newton campaign towards young open cluster NGC 6231 and focus on its rich OB star population. We present a literature-based census stars in field view with more than one hundred objects, among which 30% can be associated an X-ray source. All O-type are detected domain as soft reasonably strong emitters. 0.5-10.0 keV band, their luminosities scale bolometric $\log L_\mathrm{X} - \log L_\mathrm{bol}=-6.912\pm0.153$. Such scaling law...
Context. The detection of pulsational frequencies in stellar photometry is required as input for asteroseismological modelling. second short run (SRa02) the CoRoT mission has provided photometric data unprecedented quality and time-coverage a number O-type stars.
ABSTRACT The key empirical property of the X-ray emission from O stars is a strong correlation between bolometric and luminosities. In framework Chandra Carina Complex Project, 129 B have been detected as sources; 78 those, all with spectral type earlier than B3, enough counts for at least rough characterization. This leads to an estimate L X – BOL ratio exceptional number 60 belonging same region triples massive studied spectroscopically in X-rays. derived log( / ) −7.26 single objects,...
Abstract TIGRE is a new robotic spectroscopy telescope located in central Mexico at the La Luz Observatory of University Guanajuato. The 1.2 m fiber‐coupled to an ´echelle spectrograph with spectral resolving power exceeding 20000 over most covered range between 3800 Å and 8800 Å, small gap 130 around 5800 Å. operates robotically, i.e. it (normally) carries out all observations without any human intervention, including, particular, target selection given observing night. In this paper we...
We analyse spectroscopic observations of WR20a revealing that this star is a massive early-type binary system with most probable orbital period \sim 3.675 days. Our spectra indicate both components are likely WN6ha or O3If^*/WN6ha spectral type. The solution for days yields extremely large minimum masses 70.7 \pm 4.0 and 68.8 3.8 M_{\odot} the two stars. These properties make cornerstone study evolution.
We present the results of a long-term high-resolution spectroscopy campaign on O-type stars in NGC 6231. revise spectral classification and multiplicity these objects we constrain fundamental properties O-star population. Almost three quarters cluster are members binary system. The minimum fraction is 0.63, with half binaries having an orbital period order few days. eccentricities all short-period revised downward, henceforth match normal period-eccentricity distribution. mass-ratio...
Aims. Our goal is to determine the stellar and wind properties of seven O stars in cluster NGC 2244 three OB association Mon OB2. These give us insight into mass loss rates stars. They allow both check validity rotational mixing massive better understand effects ionizing flux mechanical energy release on surrounding interstellar medium its influence triggered star formation.
In recent years several in-depth investigations of the three Galactic Of?p stars were undertaken. These multiwavelength studies revealed peculiar properties these objects (in X-rays as well in optical): magnetic fields, periodic line profile variations, recurrent photometric changes. However, many questions remain unsolved. To clarify some stars, we have continued their monitoring. A new XMM observation and two optical datasets obtained. Additional information for prototypical trio has been...
We report the detection of a strong, organized magnetic field in secondary component massive O8III/I+O7.5V/III double-lined spectroscopic binary system HD 47129 (Plaskett's star) context Magnetism Massive Stars survey. Eight independent Stokes V observations were acquired using Echelle SpectroPolarimetric Device for Observations (ESPaDOnS) spectropolarimeter at Canada–France–Hawaii Telescope and Narval Télescope Bernard Lyot. Using least-squares deconvolution we obtain definite detections...
Athena is designed to implement the Hot and Energetic Universe science theme selected by European Space Agency for second large mission of its Cosmic Vision program. The payload consists a aperture high angular resolution X-ray optics (2 m2 at 1 keV) twelve meters away, two interchangeable focal plane instruments: Integral Field Unit (X-IFU) Wide Imager. X-IFU cryogenic spectrometer, based on array Transition Edge Sensors (TES), offering 2:5 eV spectral resolution, with ~5" pixels, over...
We report on the analysis of Chandra-ACIS data O, B, and WR stars in young association Cyg OB2. X-ray spectra 49 O-stars, 54 B-stars, 3 WR-stars are analyzed for brighter sources, epoch dependence fluxes is investigated. The O-stars OB2 follow a well-defined scaling relation between their bolometric luminosities: . This excellent agreement with one previously derived Carina OB1 association. Except brightest O-star binaries, there no general overluminosity due to colliding winds binaries....
We present a detailed, extensive investigation of the photometric and spectroscopic behaviour WR 30a. This star is definitely binary system with period around 4.6 d. propose value . The identification components as WO4+O5((f)) indicates massive evolved system; O5 component main-sequence or, more likely, giant star. radial velocities O yield circular orbit an amplitude mass function 0.013 spectrum 30a exhibits strong profile variations broad emission lines that are phase-locked orbital...
Aims.The properties of the early-type stars in core Westerlund 2 cluster are examined order to establish a link between and very massive Wolf-Rayet binary WR 20a as well H ii complex RCW 49.
We analyse the optical spectrum of very massive binary system WR 20a (WN6ha + WN6ha). The most prominent emission lines, Hα and He ii λ 4686, display strong phase-locked profile variability. From variations their equivalent widths from a tomographic analysis, we find that part line probably arises in wind interaction region between stars. Our analysis indicates reddening mag distance ~ kpc, suggesting star actually belongs to open cluster Westerlund 2. location at ∼1.1 pc core could indicate...
Aims. We present the results obtained from a long-term spectroscopic campaign devoted to multiplicity of O-type stars in young open cluster NGC2244 and Mon OB2 association. Methods. Our monitoring was performed over several years, allowing us probe different time-scales. For each star, spectral diagnostic tools are applied, order search for line shifts profile variations. also measure projected rotational velocity revisit classification. Results. In our sample, were previously considered as...
We present the results from spectroscopic monitoring of WR 140 (WC7pd + O5.5fc) during its latest periastron passage in 2009 January. The observational campaign consisted a constructive collaboration between amateur and professional astronomers. It took place at six locations, including Teide Observatory, Observatoire de Haute Provence, Dominion Astrophysical Observatory du Mont Mégantic. is known as archetype colliding-wind binaries it has relatively long period (8 yr) high eccentricity...
Probing the structures of stellar winds is prime importance for understanding massive stars. Based on their optical spectral morphology and variability, stars Oef class have been suggested to feature large-scale in wind. High-resolution X-ray spectroscopy time-series observations presumably-single O-type can help us understand physics winds. We collected XMM-Newton coordinated O6Ief star lambda Cep study its variability analyse high-resolution spectrum. investigate line profile He II 4686...