The Milky Way’s stellar disk

Rix, Hans─Walter; Bovy, Jo

doi:10.1007/s00159-013-0061-8

Cited by 256 publications

(148 citation statements)

References 228 publications

Supporting

Mentioning

139

Contrasting

Order By: Relevance

“…The solid black lines in each panel display the total number of stars in the annulus 7 < r < 9 kpc. A negative trend is seen for both |z| and |v z | as expected from observations (e.g., Katz et al 2011;Schlesinger et al 2012;Rix & Bovy 2013). As in the |z|−σ z relation, we find a flattening at |z| 2 kpc for |z|−[Fe/H], as well as in the |v z |−[Fe/H] relation at |v z | 90 km s −1 .…”

Section: Vertical Structure Of the Local Disksupporting

confidence: 87%

“…We extracted the data points from Fig. 15 by Rix & Bovy (2013), where a comparison was made between Mean metallicity as a function of distance from the disk plane, |z|, in the range 6 < r < 10 kpc. Red filled circles and error bars show SEGUE data from Schlesinger et al (2012), while the bluedashed line represents the Bovy et al model.…”

Section: Mean Metallicity As a Function Of Distance From The Disk Planementioning

confidence: 99%

See 1 more Smart Citation

Chemodynamical evolution of the Milky Way disk

Minchev

Chiappini

Martig

2013

A&A

432

574

View full text Add to dashboard Cite

In the first paper of this series, we present a new approach for studying the chemo-dynamical evolution in disk galaxies, which consists of fusing disk chemical evolution models with compatible numerical simulations of galactic disks. This method avoids known star formation and chemical enrichment problems encountered in simulations. Here we focus on the Milky Way, by using a detailed thindisk chemical evolution model (matching local observables, which are weakly affected by radial migration) and a simulation in the cosmological context, with dynamical properties close to those of our Galaxy. We examine in detail the interplay between in situ chemical enrichment and radial migration and their impact on key observables in the solar neighborhood, e.g., the age-metallicityvelocity relation, the metallicity distribution, and gradients in the radial and vertical directions. We show that, due to radial migration from mergers at high redshift and the central bar at later times, a sizable fraction of old metal-poor high-[α/Fe] stars can reach the solar vicinity. This naturally accounts for a number of recent observations related to both the thin and thick disks, despite the fact that we use thin-disk chemistry only. Although significant radial mixing is present, the slope in the age-metallicity relation is only weakly affected, with a scatter compatible with recent observational work. While we find a smooth density distribution in the [O/Fe]-[Fe/H] plane, we can recover the observed discontinuity by selecting particles according to kinematic criteria used in high-resolution samples to define the thin and thick disks. We outline a new method for estimating the birth place of the Sun and predict that the most likely radius lies in the range 4.4 < r < 7.7 kpc (for a current location at r = 8 kpc). A new, unifying model for the Milky Way thick disk is offered, where both mergers and radial migration play a role at different stages of the disk evolution. We show that in the absence of early-on massive mergers the vertical velocity dispersion of the oldest stars is underestimated by a factor of ∼2 compared with observations. We can, therefore, argue that the Milky Way thick disk is unlikely to have been formed through a quiescent disk evolution. An observational test involving both chemical and kinematic information must be devised to ascertain this possibility.

show abstract

Section: Vertical Structure Of the Local Disksupporting

confidence: 87%

Section: Mean Metallicity As a Function Of Distance From The Disk Planementioning

confidence: 99%

Chemodynamical evolution of the Milky Way disk

Minchev

Chiappini

Martig

2013

A&A

432

574

View full text Add to dashboard Cite

show abstract

“…As discussed in detail by Bovy et al (2012) and Rix & Bovy (2013), the correct model of star counts is an inhomogeneous Poisson process. This process is characterized by a rate function λ(O|θ) that specifies the model prediction for the number of stars as a function of O = (l, b, D, m, c, [Fe/H]); the model is parameterized by parameters θ.…”

Section: Likelihood-based Density Modeling and The Effective Survey Vmentioning

confidence: 99%

On Galactic Density Modeling in the Presence of Dust Extinction

Bovy

Rix

Green

et al. 2016

ApJ

Self Cite

259

230

View full text Add to dashboard Cite

Inferences about the spatial density or phase-space structure of stellar populations in the Milky Way require a precise determination of the effective survey volume. The volume observed by surveys such as Gaia or near-infrared spectroscopic surveys, which have good coverage of the Galactic midplane region, is highly complex because of the abundant small-scale structure in the three-dimensional interstellar dust extinction. We introduce a novel framework for analyzing the importance of smallscale structure in the extinction. This formalism demonstrates that the spatially-complex effect of extinction on the selection function of a pencil-beam or contiguous sky survey is equivalent to a lowpass filtering of the extinction-affected selection function with the smooth density field. We find that the angular resolution of current 3D extinction maps is sufficient for analyzing Gaia sub-samples of millions of stars. However, the current distance resolution is inadequate and needs to be improved by an order of magnitude, especially in the inner Galaxy. We also present a practical and efficient method for properly taking the effect of extinction into account in analyses of Galactic structure through an effective selection function. We illustrate its use with the selection function of red-clump stars in APOGEE using and comparing a variety of current 3D extinction maps.

show abstract

“…Bovy et al (2012a) find that mass-weighted scale-height distribution smoothly varies and that there is no thin-thick disk bi-modality (i.e., the MW has no distinct thick disk). We refer the reader to Ivezić et al (2012) and Rix & Bovy (2013) for more recent reviews of the stellar disk(s) and populations. While considering that the thick disk was formed by one single mechanism is most probably too semplicistic, several different scenarios have been proposed for the formation of thick disk: the heating of a pre-existing old thin disk via minor mergers (e.g., Quinn et al 1993;Villalobos & Helmi 2008), the direct accretion of stars from disrupted satellites (e.g., Abadi et al 2003), gas accretion at high redshift and stars formed in situ (e.g., Brook et al 2005), and radial migration of stellar orbits (e.g., Schönrich & Binney 2009a,b;Loebman et al 2011).…”

Section: Introductionmentioning

confidence: 99%

Kinematics and chemical properties of the Galactic stellar populations

Adibekyan

Figueira

Santos

et al. 2013

A&A

159

202

View full text Add to dashboard Cite

Aims. We analyzed chemical and kinematical properties of about 850 FGK solar neighborhood long-lived dwarfs observed with the HARPS high-resolution spectrograph. The stars in the sample have log g ≥ 4 dex, 5000 ≤ T eff ≤ 6500 K, and −1.39 ≤ [Fe/H] ≤ 0.55 dex. The aim of this study is to characterize and explore the kinematics and chemical properties of stellar populations of the Galaxy in order to understand their origins and evolution. Methods. We applied a purely chemical analysis approach based on the [α/Fe] vs. [Fe/H] plot to separate Galactic stellar populations into the thin disk, thick disk, and high-α metal-rich (hαmr). Then, we explored the population's stellar orbital eccentricity distributions, their correlation with metallicity, and rotational velocity gradients with metallicity in the Galactic disks to provide constraints on the various formation models. Results. We identified a gap in the [α/Fe]-[Fe/H] plane for the α-enhanced stars, and by performing a bootstrapped Monte Carlo test we obtained a probability higher than 99.99% that this gap is not due to small-number statistics. Our analysis shows a negative gradient of the rotational velocity of the thin disk stars with [Fe/H] (-17 km s −1 dex −1 ), and a steep positive gradient for both the thick disk and hαmr stars with the same magnitude of about +42 km s −1 dex −1 . For the thin disk stars we observed no correlation between orbital eccentricities and metallicity, but observed a steep negative gradient for the thick disk and hαmr stars with practically the same magnitude (≈-0.18 dex −1 ). The correlations observed for the nearby stars (on average 45 pc) using high-precision data, in general agree well with the results obtained for the SDSS sample of stars located farther from the Galactic plane. Conclusions. Our results suggest that radial migration played an important role in the formation and evolution of the thin disk. For the thick disk stars it is not possible to reach a firm conclusion about their origin. Based on the eccentricity distribution of the thick disk stars only their accretion origin can be ruled out, and the heating and migration scenario could explain the positive steep gradient of V φ with [Fe/H]. When we analyzed the hαmr stellar population we found that they share properties of both the thin and thick disk population. A comparison of the properties of the hαmr stars with those of the subsample of stars from the N-body/SPH simulation using radial migration suggest that they may have originated from the inner Galaxy. Further detailed investigations would help to clarify their exact nature and origin.

show abstract

The Milky Way’s stellar disk

Cited by 256 publications

References 228 publications

Chemodynamical evolution of the Milky Way disk

Chemodynamical evolution of the Milky Way disk

On Galactic Density Modeling in the Presence of Dust Extinction

Kinematics and chemical properties of the Galactic stellar populations

Contact Info

Product

Resources

About