Catalogue général de vitesses radiales moyennes pour les étoiles
 galactiques

Barbier-Brossat, M.; Figon, P.

doi:10.1051/aas:2000149

Cited by 193 publications

(201 citation statements)

References 4 publications

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“…The standard errors of the average radial velocities from these lines are generally below 0.4 km s −1 . Agreement with the radial velocities from Barbier-Brossat et al (1994) is good with only one thick disk star (Hip 14086) having a significantly different value. However, this deviation does not affect the star's initial classification as a thick disk star.…”

Section: Radial Velocitiesmentioning

confidence: 67%

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Elemental abundance trends in the Galactic thin and thick disks as traced by nearby F and G dwarf stars

Bensby

Feltzing

Lundström

2003

A&A

852

119

1,264

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Abstract. Based on spectra from F and G dwarf stars, we present elemental abundance trends in the Galactic thin and thick disks in the metallicity regime −0.8 [Fe/H] +0.4. Our findings can be summarized as follows. 1) Both the thin and the thick disks show smooth and distinct abundance trends that, at sub-solar metallicities, are clearly separated. 2) For the α-elements the thick disk shows signatures of chemical enrichment from SNe type Ia.3) The age of the thick disk sample is in the mean older than the thin disk sample. 4) Kinematically, there exist thick disk stars with super-solar metallicities. Based on these findings, together with other constraints from the literature, we discuss different formation scenarios for the thick disk. We suggest that the currently most likely formation scenario is a violent merger event or a close encounter with a companion galaxy. Based on kinematics the stellar sample was selected to contain stars with high probabilities of belonging either to the thin or to the thick Galactic disk. The total number of stars are 66 of which 21 belong to the thick disk and 45 to the thin disk. The analysis is based on high-resolution spectra with high signal-to-noise (R ∼ 48 000 and S /N 150, respectively) recorded with the FEROS spectrograph on La Silla, Chile. Abundances have been determined for four α-elements (Mg, Si, Ca, and Ti), for four even-nuclei iron peak elements (Cr, Fe, Ni, and Zn), and for the light elements Na and Al, from equivalent width measurements of ∼30 000 spectral lines. An extensive investigation of the atomic parameters, log g f -values in particular, have been performed in order to achieve abundances that are trustworthy. Noteworthy is that we find for Ti good agreement between the abundances from Ti  and Ti . Our solar Ti abundances are in concordance with the standard meteoritic Ti abundance.

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Section: Radial Velocitiesmentioning

confidence: 67%

“…Since the selection of the stellar sample was based on the U LSR , V LSR , and W LSR velocities, which were calculated using radial velocities from Barbier-Brossat et al (1994), we need to confirm the radial velocities in order to verify the calculated probabilities.…”

Section: Radial Velocitiesmentioning

confidence: 99%

Elemental abundance trends in the Galactic thin and thick disks as traced by nearby F and G dwarf stars

Bensby

Feltzing

Lundström

2003

A&A

852

119

1,264

View full text Add to dashboard Cite

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“…Then, we searched the SIMBAD/CDS databases (Wenger et al 2000) for radial velocity information using the data mining tools available on the site. The radial velocities that we use in this work come from Wilson (1953), Duflot et al (1995), Barbier-Brossat & Figon (2000), Torres et al (2006), Gontcharov (2006), Holmberg et al (2007), Mermilliod et al (2009), Chen et al (2011), Song et al (2012, Kordopatis et al (2013) and Desidera et al (2015). We found radial velocity for 184 stars of our sample.…”

Section: Appendix A: Ad Hoc Force To Account For Type II Migrationmentioning

confidence: 69%

Origin of the wide-orbit circumbinary giant planet HD 106906

Rodet

Beust

Bonnefoy

et al. 2017

A&A

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Context. A giant planet has been recently resolved at a projected distance of 730 au from the tight pair of young (∼13 Myr) intermediate-mass stars HD 106906AB in the Lower Centaurus Crux (LCC) group. The stars are surrounded by a debris disk which displays a ring-like morphology and strong asymmetries at multiple scales. Aims. We aim to study the likelihood of a scenario where the planet formed closer to the stars in the disk, underwent inward diskinduced migration, and got scattered away by the binary star before being stabilized by a close encounter (fly-by). Methods. We performed semi-analytical calculations and numerical simulations (Swift_HJS package) to model the interactions between the planet and the two stars. We accounted for the migration as a simple force. We studied the LCC kinematics to set constraints on the local density of stars, and therefore on the fly-by likelihood. We performed N-body simulations to determine the effects of the planet trajectories (ejection and secular effects) onto the disk morphology. Results. The combination of the migration and mean-motion resonances with the binary star (often 1:6) can eject the planet. Nonetheless, we estimate that the fly-by hypothesis decreases the scenario probability to less than 10 −7 for a derived local density of stars of 0.11 stars/pc 3 . We show that the concomitant effect of the planet and stars trajectories induce spiral-features in the disk which may correspond to the observed asymmetries. Moreover, the present disk shape suggests that the planet is on an eccentric orbit. Conclusions. The scenario we explored is a natural hypothesis if the planet formed within a disk. Conversely, its low probability of occurrence and the fact that HD 106906 b shares some characteristics with other systems in Sco-Cen (e.g., HIP 78530, in terms of mass ratio and separation) may indicate an alternative formation pathway for those objects.

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“…One of such stars is HIP 21539 for which we adopted 30 km s −1 as formal error. We used this value because this radial velocity measurement (Barbier-Brossat et al 1994) most probably comes from observation with an obiective prism which have the precision of this order.…”

Section: Drawing a Stellar Clonementioning

confidence: 99%

On the accuracy of close stellar approaches determination

Dybczyński

Berski

2015

Monthly Notices of the Royal Astronomical Society

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The aim of this paper is to demonstrate the accuracy of our knowledge of close stellar passage distances in the pre-GAIA era. We used the most precise astrometric and kinematic data available at the moment and prepared a list of 40 stars nominally passing (in the past or future) closer than 2 pc from the Sun. We used a full gravitational potential of the Galaxy to calculate the motion of the Sun and a star from their current positions to the proximity epoch. For this calculations we used a numerical integration in rectangular, Galactocentric coordinates. We showed that in many cases the numerical integration of the star motion gives significantly different results than popular rectilinear approximation. We found several new stellar candidates for close visitors in past or in future.We used a covariance matrices of the astrometric data for each star to estimate the accuracy of the obtained proximity distance and epoch. To this aim we used a Monte Carlo method, replaced each star with 10 000 of its clones and studied the distribution of their individual close passages near the Sun. We showed that for contemporary close neighbours the precision is quite good but for more distant stars it strongly depends on the quality of astrometric and kinematic data. Several examples are discussed in detail, among them the case of HIP 14473. For this star we obtained the nominal proximity distance as small as 0.22 pc 3.78 Myr ago. However there exist strong need for more precise astrometry of this star since the proximity point uncertainty is unacceptably large.

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Catalogue général de vitesses radiales moyennes pour les étoiles galactiques

Cited by 193 publications

References 4 publications

Elemental abundance trends in the Galactic thin and thick disks as traced by nearby F and G dwarf stars

Elemental abundance trends in the Galactic thin and thick disks as traced by nearby F and G dwarf stars

Origin of the wide-orbit circumbinary giant planet HD 106906

On the accuracy of close stellar approaches determination

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