Publications (35)
The Gaia-ESO Survey: detection and characterization of single line spectroscopic binaries
T. Merle, M. Van der Swaelmen, S. Van Eck +26
Recent and on-going large ground-based multi-object spectroscopic surveys allow to significantly increase the sample of spectroscopic binaries to get insight into their statistical…
The GALAH survey: Multiple stars and our Galaxy. I. A comprehensive method for deriving properties of FGK binary stars
G. Traven, S. Feltzing, T. Merle +24
Binary stellar systems form a large fraction of the Galaxy's stars. They are useful as laboratories for studying the physical processes taking place within stars, and must be corre…
The Gaia-ESO Public Spectroscopic Survey: Implementation, data products, open cluster survey, science, and legacy
S. Randich, G. Gilmore, L. Magrini +161
In the last 15 years different ground-based spectroscopic surveys have been started (and completed) with the general aim of delivering stellar parameters and elemental abundances f…
The Gaia-ESO Survey: homogenisation of stellar parameters and elemental abundances
A. Hourihane, P. Francois, C. C. Worley +59
The Gaia-ESO Survey is a public spectroscopic survey that has targeted stars covering all major components of the Milky Way from the end of 2011 to 2018, delivering i…
Binary properties of CH and Carbon-Enhanced Metal-Poor stars
A. Jorissen, S. Van Eck, H. Van Winckel +8
The HERMES spectrograph installed on the 1.2-m Mercator telescope has been used to monitor the radial velocity of 13 low-metallicity carbon stars, among which 7 Carbon-Enhanced Met…
Potassium: a new actor on the globular cluster chemical evolution stage. The case of NGC 2808
A. Mucciarelli, M. Bellazzini, T. Merle +3
We derive [K/Fe] abundance ratios for 119 stars in the globular cluster NGC 2808, all of them having O, Na, Mg and Al abundances homogeneously measured in previous works. We detect…
The Gaia-ESO Public Spectroscopic Survey: Motivation, implementation, GIRAFFE data processing, analysis, and final data products
G. Gilmore, S. Randich, C. C. Worley +165
The Gaia-ESO Public Spectroscopic Survey is an ambitious project designed to obtain astrophysical parameters and elemental abundances for 100,000 stars, including large representat…
Tomography of cool giant and supergiant star atmospheres II. Signature of convection in the atmosphere of the red supergiant star Cep
K. Kravchenko, A. Chiavassa, S. Van Eck +4
Red supergiants are cool massive stars and are the largest and the most luminous stars in the universe. They are characterized by irregular or semi-regular photometric variations,…
The Gaia-ESO Survey: double, triple and quadruple-line spectroscopic binary candidates
T. Merle, S. Van Eck, A. Jorissen +35
The Gaia-ESO Survey (GES) is a large spectroscopic survey that provides a unique opportunity to study the distribution of spectroscopic multiple systems among different populations…
The Carina Project. V. The impact of NLTE effects on the iron content
M. Fabrizio, T. Merle, F. Thévenin +21
We have performed accurate iron abundance measurements for 44 red giants (RGs) in the Carina dwarf spheroidal (dSph) galaxy. We used archival, high-resolution spectra (R~38,000) co…
Ages and ZAMS spin distribution of stars in detached eclipsing binaries
T. Merle, W. Van Rensbergen, L. Siess +4
Benchmarking fundamental stellar properties is essential for calibrating evolutionary models and establishing empirical relationships between mass, radius, luminosity and related s…
The SB9 catalogue: status, comparison with non-single stars from Gaia DR3 and evolution to SBX
T. Merle, A. Jorissen, S. Alexandre +9
The Ninth Catalogue of Spectroscopic Binary Orbits (SB9) is a comprehensive compilation of spectroscopic binaries (SBs) with orbital parameters sourced from literature, comprising…
IP Eri: A surprising long-period binary system hosting a He white dwarf
T. Merle, A. Jorissen, T. Masseron +3
We determine the orbital elements for the K0 IV + white dwarf (WD) system IP Eri, which appears to have a surprisingly long period of 1071 d and a significant eccentricity of 0.25.…
The Gaia-ESO Survey: The DR5 analysis of the medium-resolution GIRAFFE and high-resolution UVES spectra of FGK-type stars
C. C. Worley, R. Smiljanic, L. Magrini +42
The Gaia-ESO Survey is an European Southern Observatory (ESO) public spectroscopic survey that targeted stars in the Milky Way covering the major populations of the disk, bu…
Comparative Modelling of the Spectra of Cool Giants
T. Lebzelter, U. Heiter, C. Abia +24
Our ability to extract information from the spectra of stars depends on reliable models of stellar atmospheres and appropriate techniques for spectral synthesis. Various model code…
Atmosphere of Betelgeuse before and during the Great Dimming event revealed by tomography
K. Kravchenko, A. Jorissen, S. Van Eck +7
Despite being the best studied red supergiant star in our Galaxy, the physics behind the photometric variability and mass loss of Betelgeuse is poorly understood. Moreover, recentl…
The Gaia-ESO Survey: new spectroscopic binaries in the Milky Way
M. Van der Swaelmen, T. Merle, S. Van Eck +14
The Gaia-ESO Survey (GES) is a large public spectroscopic survey which acquired spectra for more than 100000 stars across all major components of the Milky Way. In addition to atmo…
Tomography of the red supergiant star μ Cep
K. Kravchenko, A. Chiavassa, S. Van Eck +3
A tomographic method, aiming at probing velocity fields at depth in stellar atmospheres, is applied to the red supergiant star μ Cep and to snapshots of 3D radiative-hydrodynamics…
Binaries masses and luminosities with Gaia DR3
S. Chevalier, C. Babusiaux, T. Merle +1
The recent Gaia third data release (DR3) has brought some new exciting data about stellar binaries. It provides new opportunities to fully characterize more stellar systems and con…
When binaries keep track of recent nucleosynthesis: The Zr - Nb pair in extrinsic stars as an s-process diagnostic
D. Karinkuzhi, S. Van Eck, A. Jorissen +9
Barium stars are s-process enriched giants. They owe their chemical peculiarities to a past mass transfer phase. During which they were polluted by their binary companion, which at…
The Belgian repository of fundamental atomic data and stellar spectra (BRASS) II. Quality assessment of atomic data for unblended lines in FGK stars
M. Laverick, A. Lobel, P. Royer +7
Fundamental atomic transition parameters, such as oscillator strengths and wavelengths, play a key role in modelling and understanding the chemical composition of stars in the univ…
The chemical compositions of the 2 new HgMn stars HD 30085 and HD 30963. Comparison to Lupi A, Cap and HD 174567
R. Monier, E. Griffin, M. Gebran +3
We report on a detailed abundance study of the fairly bright slow rotators HD 30085 (A0 IV), HD 30963 (B9 III) and HD 174567 (A0 V), hitherto reported as normal stars and the sharp…
Spectroscopic binaries among AGB stars from HERMES/Mercator: the case of V Hya
A. Jorissen, S. Van Eck, T. Merle +1
We report on our search for spectroscopic binaries among a sample of AGB stars. Observations were carried out in the framework of the monitoring of radial velocities of (candidate)…
The strange case of NGC2419: stellar populations, chemical composition, dynamics
M. Bellazzini, A. Mucciarelli, R. A. Ibata +10
A few years ago we started an observational campaign aimed at the thorough study of the massive and remote globular cluster NGC2419. We have used the collected data, e.g., to test…
Low-mass low-metallicity AGB stars as an efficient i-process site explaining CEMP-rs stars
D. Karinkuzhi, S. Van Eck, S. Goriely +5
Among Carbon-Enhanced Metal-Poor (CEMP) stars, some are found to be enriched in s-process elements (CEMP-s), in r-process elements (CEMP-r) or in both s- and r-process elements (CE…
To Ba or not to Ba: Enrichment in s-process elements in binary systems with WD companions of various masses
T. Merle, A. Jorissen, S. Van Eck +2
The enrichment in s-process elements of barium stars is known to be due to pollution by mass transfer from a companion formerly on the thermally-pulsing asymptotic giant branch (AG…
MELCHIORS: The Mercator Library of High Resolution Stellar Spectroscopy
P. Royer, T. Merle, K. Dsilva +71
Over the past decades, libraries of stellar spectra have been used in a large variety of science cases, including as sources of reference spectra for a given object or a given spec…
The Carina Project. IV. radial velocity distribution
M. Fabrizio, M. Nonino, G. Bono +16
We present new and accurate radial velocity (RV) measurements of luminous stars of all ages (old horizontal branch, intermediate--age red clump, and young blue plume, as well as re…
Sr and Ba abundance determinations: comparing machine-learning with star-by-star analyses -- High-resolution re-analysis of suspected LAMOST barium stars
D. Karinkuzhi, S. Van Eck, A. Jorissen +6
A new large sample of 895 s-process-rich candidates out of 454180 giant stars surveyed by LAMOST at low spectral resolution (R ~ 1800) has been reported by Norfolk et al. (2019; he…
The Potassium abundance in the globular clusters NGC104, NGC6752 and NGC6809
A. Mucciarelli, T. Merle, M. Bellazzini
We derived Potassium abundances in red giant branch stars in the Galactic globular clusters NGC104 (144 stars), NGC6752 (134 stars) and NGC6809 (151 stars) using high-resolution sp…
Abundance of heavy r-process elements in CEMP-rs stars: The role of the i-process
A. M. Riyas, D. Karinkuzhi, S. Van Eck +6
Carbon-enhanced metal-poor (CEMP) stars are ancient stars enriched in carbon and heavy elements. Some of these stars exhibit enhanced s-process and/or r-process elements, hence are…
Chromosphere of K giant stars Geometrical extent and spatial structure detection
P. Berio, T. Merle, F. Thevenin +19
We aim to constrain the geometrical extent of the chromosphere of non-binary K giant stars and detect any spatial structures in the chromosphere. We performed observations with the…
Effective collision strengths between Mg I and electrons
T. Merle, F. Thévenin, O. Zatsarinny
The treatment of the inelastic collisions with electrons and hydrogen atoms are the main source of uncertainties in non-Local Thermodynamic Equilibrium (LTE) spectral line computat…
A spectroscopic quadruple as a possible progenitor of sub-Chandrasekhar Type Ia supernovae
T. Merle, A. S. Hamers, S. Van Eck +13
Binaries have received much attention as possible progenitors of Type Ia supernova (SNIa) explosions, but long-term gravitational effects in tight triple or quadruple systems could…
News from the Galactic suburbia: the chemical composition of the remote globular cluster NGC 2419
A. Mucciarelli, M. Bellazzini, R. Ibata +4
We present the chemical analysis of 49 giant stars of the globular cluster NGC 2419, using medium resolution spectra collected with the multi-object spectrograph DEIMOS@Keck. Previ…