<i>Gaia</i>FGK benchmark stars: abundances of<i>α</i>and iron-peak elements

Jofré, P.; Heiter, U.; Soubiran, C.; Blanco-Cuaresma, S.; Masseron, T.; Nordlander, Thomas; Chemin, L.; Worley, C. C.; Eck, S. Van; Hourihane, A.; Gilmore, G.; Adibekyan, V.; Bergemann, M.; Cantat-Gaudin, T.; Delgado-Mena, E.; Hernández, J. I. González; Guiglion, G.; Lardo, C.; Laverny, P. de; Lind, Karin; Magrini, L.; Mikolaitis, Š.; Montes, D.; Pancino, E.; Recio–Blanco, A.; Sordo, R.; Sousa, S. G.; Tabernero, H. M.; Vallenari, A.

doi:10.1051/0004-6361/201526604

Cited by 138 publications

(101 citation statements)

References 144 publications

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“…In Table 3 we report the values of the atmospheric parameters and abundances of the Gaia benchmark stars. The results we obtain with our new method are in excellent agreement with the results by Jofré et al (2015Jofré et al ( , 2018 and with Gaia-ESO, in particular for ξ (rows highlighted in yellow). We obtain very similar results, which confirms our hypothesis that the standard analysis produces good results for older stars ( 600 Myr).…”

Section: Titanium and Iron Linessupporting

confidence: 87%

“…In this figure, we also report the values for the Gaia benchmark stars we analysed. The benchmarks are quiet stars, with log R HK < −4.8 , and we obtain the same value as Jofré et al (2015) with the new approach, as reported in Table 3. We also note that the ξ value we obtain for β Hyi is slightly higher than the values obtained for the other benchmark stars, which is mainly due to the slightly advanced evolutionary stage.…”

Section: Effect Of Stellar Activitymentioning

confidence: 57%

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The Gaia-ESO Survey: a new approach to chemically characterising young open clusters

Baratella

D’Orazi

Carraro

et al. 2020

A&A

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Context. Open clusters are recognised as excellent tracers of Galactic thin-disc properties. At variance with intermediate-age and old open clusters, for which a significant number of studies is now available, clusters younger than 150 Myr have been mostly overlooked in terms of their chemical composition until recently (with few exceptions). On the other hand, previous investigations seem to indicate an anomalous behaviour of young clusters, which includes (but is not limited to) slightly sub-solar iron (Fe) abundances and extreme, unexpectedly high barium (Ba) enhancements. Aims. In a series of papers, we plan to expand our understanding of this topic and investigate whether these chemical peculiarities are instead related to abundance analysis techniques. Methods. We present a new determination of the atmospheric parameters for 23 dwarf stars observed by the Gaia-ESO survey in five young open clusters (τ <150 Myr) and one star-forming region (NGC 2264). We exploit a new method based on titanium (Ti) lines to derive the spectroscopic surface gravity, and most importantly, the microturbulence parameter. A combination of Ti and Fe lines is used to obtain effective temperatures. We also infer the abundances of Fe i, Fe ii, Ti i, Ti ii, Na i, Mg i, Al i, Si i, Ca i, Cr i, and Ni i. Results. Our findings are in fair agreement with Gaia-ESO iDR5 results for effective temperatures and surface gravities, but suggest that for very young stars, the microturbulence parameter is over-estimated when Fe lines are employed. This affects the derived chemical composition and causes the metal content of very young clusters to be under-estimated. Conclusions. Our clusters display a metallicity [Fe/H] between +0.04±0.01 and +0.12±0.02; they are not more metal poor than the Sun. Although based on a relatively small sample size, our explorative study suggests that we may not need to call for ad hoc explanations to reconcile the chemical composition of young open clusters with Galactic chemical evolution models.

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Section: Titanium and Iron Linessupporting

confidence: 87%

Section: Effect Of Stellar Activitymentioning

confidence: 57%

The Gaia-ESO Survey: a new approach to chemically characterising young open clusters

Baratella

D’Orazi

Carraro

et al. 2020

A&A

Self Cite

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“…Our abundance ratios were measured for the HERMES observation of Arcturus. Literature studies provided abundance ratios for the Arcturus atlas (Hinkle et al 2000); Jofré et al (2015) also included a spectrum observed with the NARVAL spectrograph.…”

Section: A4 Comparison Of Herbs and Galah Dr2 Abundancesmentioning

confidence: 99%

HERBS II: Detailed chemical compositions of Galactic bulge stars

Duong

Asplund

Nataf

et al. 2019

Monthly Notices of the Royal Astronomical Society

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This work explores the detailed chemistry of the Milky Way bulge using the HERMES spectrograph on the Anglo-Australian Telescope. Here we present the abundance ratios of 13 elements for 832 red giant branch and clump stars along the minor bulge axis at latitudes b = −10 • , −7.5 and −5 • . Our results show that none of the abundance ratios vary significantly with latitude. We also observe disk-like [Na/Fe] abundance ratios, which indicates the bulge does not contain helium-enhanced populations as observed in some globular clusters. Helium enhancement is therefore not the likely explanation for the double red-clump observed in the bulge. We confirm that bulge stars mostly follow abundance trends observed in the disk. However, this similarity is not confirmed across for all elements and metallicity regimes. The more metal-poor bulge population at [Fe/H] −0.8 is enhanced in the elements associated with core collapse supernovae (SNeII). In addition, the [La/Eu] abundance ratio suggests higher r-process contribution, and likely higher star formation in the bulge compared to the disk. This highlights the complex evolution in the bulge, which should be investigated further, both in terms of modelling; and with additional observations of the inner Galaxy.

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“…The three host stars were found within the Hypatia Catalog 1 , an amalgamate database of stellar abundances for nearby FGKM-type stars (Hinkel et al 2014). HD 9446 was observed by 7 groups (Ramírez et al 2007;Ramírez et al 2009;Baumann et al 2010;Brugamyer et al 2011;Ramírez et al 2012;Ramírez et al 2013;Brewer et al 2016), while HD 43691 and HD 179079 were both observed by 6 groups Brugamyer et al 2011;Kang et al 2011;Petigura & Marcy 2011;Brewer et al 2016 andMarcy 2011;Maldonado et al 2013;Ramírez et al 2014;Jofré et al 2015;Brewer et al 2016;Mal- donado & Villaver 2016, respectively). All datasets are renormalized to the same solar scale within Hypatia, namely Lodders et al (2009), such that they are more easily comparable.…”

Section: Stellar Propertiesmentioning

confidence: 96%

Orbital Refinement and Stellar Properties for the HD 9446, HD 43691, and HD 179079 Planetary Systems

Hill

Močnik

Kane

et al. 2020

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The Transit Ephemeris Refinement and Monitoring Survey (TERMS) is a project which aims to detect transits of intermediate-long period planets by refining orbital parameters of the known radial velocity planets using additional data from ground based telescopes, calculating a revised transit ephemeris for the planet, then monitoring the planet host star during the predicted transit window. Here we present the results from three systems that had high probabilities of transiting planets: HD 9446 b & c, HD 43691 b, & HD 179079 b. We provide new radial velocity (RV) measurements that are then used to improve the orbital solution for the known planets. We search the RV data for indications of additional planets in orbit and find that HD 9446 shows a strong linear trend of 4.8σ. Using the newly refined planet orbital solutions, which include a new best-fit solution for the orbital period of HD 9446 c, and an improved transit ephemerides, we found no evidence of transiting planets in the photometry for each system. Transits of HD 9446 b can be ruled out completely and transits HD 9446 c & HD 43691 b can be ruled out for impact parameters up to b = 0.5778 and b = 0.898 respectively due to gaps in the photometry. A transit of HD 179079 b cannot be ruled out however due to the relatively small size of this planet compared to the large star and thus low signal to noise. We determine properties of the three host stars through spectroscopic analysis and find through photometric analysis that HD 9446 exhibits periodic variability.

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GaiaFGK benchmark stars: abundances ofαand iron-peak elements

Cited by 138 publications

References 144 publications

The Gaia-ESO Survey: a new approach to chemically characterising young open clusters

The Gaia-ESO Survey: a new approach to chemically characterising young open clusters

HERBS II: Detailed chemical compositions of Galactic bulge stars

Orbital Refinement and Stellar Properties for the HD 9446, HD 43691, and HD 179079 Planetary Systems

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