A New Stellar Chemo-Kinematic Relation Reveals the Merger History of the Milky Way Disk

Minchev, Ivan; Chiappini, Cristina; Martig, Marie; Steinmetz, Matthias; Jong, Roelof S. de; Boeche, C.; Scannapieco, Cecilia; Zwitter, T.; Wyse, Rosemary F. Ġ.; Binney, James; Bland-Hawthorn, Joss; Bienaymé, O.; Famaey, Benoît; Freeman, K. C.; Gibson, Brad K.; Grebel, E. K.; Gilmore, G.; Helmi, Amina; Kordopatis, G.; Lee, Young Sun; Munari, U.; Navarro, Julio F.; Parker, Quentin A.; Quillen, Alice C.; Reid, Warren A.; Siebert, A.; Siviero, A.; Seabroke, G. M.; Watson, Fred; Williams, M.

doi:10.1088/2041-8205/781/1/l20

Cited by 81 publications

(77 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This work illustrates the effect that more robust definitions of MW stellar populations (allowed by methods such as the t-SNE; Anders et al 2018, Chiappini et al in prep) can have on the recent claim that a Li decline in super-solar metallicity stars found by many authors (Delgado Mena et al 2015;Guiglion et al 2016;Fu et al 2018) would imply a revision of the lithium stellar yields at high metallicities. As shown in Anders et al (2018) and Chiappini et al (in prep), the most metal-rich thin-disk stars have most probably migrated from inner disk regions (as has been indicated by previous observations such as Casagrande et al (2011), Trevisan et al (2011), and Anders et al (2017b; see the discussion in Chiappini 2015), and cannot be modeled as part of a local thin disk without taking into account the fact that stars move out of their birth places, as is clearly shown by chemodynamical models (Minchev et al 2013, 2014band Minchev et al 2018. It is also consistent with the kinematics found in super-solar metallicity stars in the solar neighborhood, see, e.g., Wojno et al (2018).…”

Section: Resultsmentioning

confidence: 69%

“…As clearly shown by both observations (e.g., Casagrande et al 2011;Trevisan et al 2011;Anders et al 2017a) and chemodynamical models (Minchev et al (2013(Minchev et al ( , 2014b, the most metal-rich stars (those with [Fe/H] > 0.25) are typically 5-10 Gyr old. Therefore all of them will have depleted their lithium by large amounts (as discussed in 3.1).…”

Section: Effect Of Radial Migrationmentioning

confidence: 86%

“…Therefore all of them will have depleted their lithium by large amounts (as discussed in 3.1). It follows that the lithium decrease at super-solar metallicities that is observed in the solar neighborhood might be explained by radial migration, that is, that these stars were not born locally (Minchev et al 2013(Minchev et al , 2014b(Minchev et al , 2018Anders et al 2018, Chiappini et al 2018. These stars will have systematically lower lithium than young stars that were born at the solar radius (here illustrated by the R=8kpc curve).…”

Section: Effect Of Radial Migrationmentioning

confidence: 97%

See 2 more Smart Citations

Explaining the decrease in ISM lithium at super-solar metallicities in the solar vicinity

Guiglion

Chiappini

Romano

et al. 2019

A&A

Self Cite

View full text Add to dashboard Cite

We propose here that the lithium decrease at super-solar metallicities observed in high-resolution spectroscopic surveys can be explained by the interplay of mixed populations that originate in the inner regions of the Milky Way disk. The lower lithium content of these stars is a consequence of inside-out disk formation plus radial migration. In this framework, local stars with super-solar metallicities would have migrated to the solar vicinity and depleted their original lithium during their travel time. To obtain this result, we took advantage of the AMBRE catalog of lithium abundances combined with chemical evolution models that take into account the contribution to the lithium enrichment by different nucleosynthetic sources. A large proportion of migrated stars can explain the observed lower lithium abundance at super-solar metallicities. We stress that no stellar model is currently able to predict Li-depletion for these super-solar metallicity stars, and solar Li-depletion has to be assumed. In addition, no solid quantitative estimate of the proportion of migrated stars in the solar neighborhood and their travel time is currently available. Our results illustrate how important it is to properly include radial migration when chemical evolution models are compared to observations, and that in this case, the lithium decrease at larger metallicities does not necessarily imply that stellar yields have to be modified, contrary to previous claims in the literature.

show abstract

Section: Resultsmentioning

confidence: 69%

Section: Effect Of Radial Migrationmentioning

confidence: 86%

Section: Effect Of Radial Migrationmentioning

confidence: 97%

See 1 more Smart Citation

Explaining the decrease in ISM lithium at super-solar metallicities in the solar vicinity

Guiglion

Chiappini

Romano

et al. 2019

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…The r birth − σz relation was first presented in order to understand why the velocity dispersion increase with [Mg/Fe] in RAVE Giants and SEGUE G-dwarfs showed an abrupt drop at the highest [Mg/Fe] end (Minchev et al 2014b). It was found that the observations could be explained by kinematically cool, old (thus low metallicity and high [Mg/Fe]) stars arriving to the solar neighborhood from low Galactic radii (∼ 2 − 4 kpc).…”

Section: Birth Radius Vs Vertical Velocity Dispersionmentioning

confidence: 99%

Yule-Simpson’s paradox in Galactic Archaeology

Minchev

Matijevič

Guiglion

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Simpson's paradox, or Yule-Simpson effect, arises when a trend appears in different subsets of data but disappears or reverses when these subsets are combined. We describe here seven cases of this phenomenon for chemo-kinematical relations believed to constrain the Milky Way disk formation and evolution. We show that interpreting trends in relations, such as the radial and vertical chemical abundance gradients, the age-metallicity relation, and the metallicity-rotational velocity relation (MVR), can lead to conflicting conclusions about the Galaxy past if analyses marginalize over stellar age and/or birth radius. It is demonstrated that the MVR in RAVE giants is consistent with being always strongly negative, when narrow bins of [Mg/Fe] are considered. This is directly related to the negative radial metallicity gradients of stars grouped by common age (mono-age populations) due to the inside-out disk formation. The effect of the asymmetric drift can then give rise to a positive MVR trend in high-[α/Fe] stars, with a slope dependent on a given survey's selection function and observational uncertainties. We also study the variation of lithium abundance, A(Li), with [Fe/H] of AMBRE:HARPS dwarfs. A strong reversal in the positive A(Li)-[Fe/H] trend of the total sample is found for mono-age populations, flattening for younger groups of stars. Dissecting by birth radius shows strengthening in the positive A(Li)-[Fe/H] trend, shifting to higher [Fe/H] with decreasing birth radius; these observational results suggest new constraints on chemical evolution models. This work highlights the necessity for precise age estimates for large stellar samples covering wide spatial regions.

show abstract

“…In principle age is the parameter with the most power to discriminate among models of our Galaxy's history (e.g. Minchev et al 2014). However, stellar ages have only recently started being derived with reasonable error bars, and for only a relatively small sample of stars, and potential biases in the derived ages may still exist (Miglio et al 2013).…”

Section: Introductionmentioning

confidence: 99%

Chemodynamics of the Milky Way and disc formation history: Insight from the RAVE and Gaia‐ESO surveys

Kordopatis

Wyse

Binney³

2016

Astron Nachr

Self Cite

View full text Add to dashboard Cite

Multi-object spectrographs have opened a new window on the analyses of the chemo-dynamical properties of old Milky Way stars. These analyses allow us to trace back the internal mechanisms and the external factors that have influenced the evolution of our Galaxy, and therefore understand fundamental aspects of galaxy evolution in general. Here, we present recent results from the RAdial Velocity Experiment (RAVE) and the Gaia-ESO survey. These surveys explore the Milky Way properties in different ways, in terms of sample size and selection, magnitude range, and spectral resolution. We focus here on (i) the first direct detection of evidence for radial migration within the thin disc, providing insight into the history of spiral structure of the Milky Way, and (ii) the chemo-dynamical characterisation of the metal-weak thick and thin discs, for which chemo-dynamical models still have difficulties in reproducing.

show abstract

A New Stellar Chemo-Kinematic Relation Reveals the Merger History of the Milky Way Disk

Cited by 81 publications

References 36 publications

Explaining the decrease in ISM lithium at super-solar metallicities in the solar vicinity

Explaining the decrease in ISM lithium at super-solar metallicities in the solar vicinity

Yule-Simpson’s paradox in Galactic Archaeology

Chemodynamics of the Milky Way and disc formation history: Insight from the RAVE and Gaia‐ESO surveys

Contact Info

Product

Resources

About