Report
View in EDS

Observational Constraints of Radial Migration in the Galactic Disc Driven by the Slowing Bar

Bibliographic Details
Title: Observational Constraints of Radial Migration in the Galactic Disc Driven by the Slowing Bar
Authors: Zhang, HanYuan, Belokurov, Vasily, Evans, N. Wyn, Sanders, Jason L., Lu, Yuxi, Cao, Chengye, Myeong, GyuChul, Dillamore, Adam M., Kane, Sarah G., Li, Zhao-Yu
Publication Year: 2025
Collection: Astrophysics
Subject Terms: Astrophysics - Astrophysics of Galaxies
More Details: Radial migration is an important dynamical effect that has reshaped the Galactic disc, but its origin has yet to be elucidated. In this work, we present evidence that resonant dragging by the corotation of a decelerating bar could be the main driver of radial migration in the Milky Way disc. Using a test particle simulation, we demonstrate this scenario explains the two distinct age-metallicity sequences observed in the solar vicinity: the plateauing upper sequence is interpreted as stars dragged outwards by the expanding corotation of the decelerating bar and the steeper lower sequence as stars formed locally around the solar circle. The upper migrated sequence dominates at guiding radii around the current corotation radius of the bar, $R\sim7\,\mathrm{kpc}$, but rapidly dies away beyond this where the mechanism cannot operate. This behaviour naturally explains the radial dependence of the $\mathrm{[\alpha/Fe]}$-bimodality, in particular the truncation of the high-$\mathrm{[\alpha/Fe]}$ disc beyond the solar circle. Under our proposed radial migration scenario, we constrain the Milky Way bar's pattern speed evolution using the age-metallicity distribution of stars currently trapped at corotation. We find the bar likely formed with an initial pattern speed of $60-100$ km s$^{-1}$ kpc$^{-1}$ and began decelerating $6-8$ Gyr ago at a rate $-\dot{\Omega}/\Omega^2\sim0.0025-0.0040$ (where the quoted ranges include systematic uncertainties).
Comment: 17 pages, 4 figures, 4 appendices, Accepted by ApJL, https://doi.org/10.3847/2041-8213/adc261
Document Type: Working Paper
DOI: 10.3847/2041-8213/adc261
Access URL: http://arxiv.org/abs/2502.02642
Accession Number: edsarx.2502.02642
Database: arXiv
FullText Text:
  Availability: 0
CustomLinks:
  – Url: http://arxiv.org/abs/2502.02642
    Name: EDS - Arxiv
    Category: fullText
    Text: View this record from Arxiv
    MouseOverText: View this record from Arxiv
  – Url: https://resolver.ebsco.com/c/xy5jbn/result?sid=EBSCO:edsarx&genre=article&issn=&ISBN=&volume=&issue=&date=20250204&spage=&pages=&title=Observational Constraints of Radial Migration in the Galactic Disc Driven by the Slowing Bar&atitle=Observational%20Constraints%20of%20Radial%20Migration%20in%20the%20Galactic%20Disc%20Driven%20by%20the%20Slowing%20Bar&aulast=Zhang%2C%20HanYuan&id=DOI:10.3847/2041-8213/adc261
    Name: Full Text Finder (for New FTF UI) (s8985755)
    Category: fullText
    Text: Find It @ SCU Libraries
    MouseOverText: Find It @ SCU Libraries
Header DbId: edsarx
DbLabel: arXiv
An: edsarx.2502.02642
RelevancyScore: 1147
AccessLevel: 3
PubType: Report
PubTypeId: report
PreciseRelevancyScore: 1146.5634765625
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Observational Constraints of Radial Migration in the Galactic Disc Driven by the Slowing Bar
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Zhang%2C+HanYuan%22">Zhang, HanYuan</searchLink><br /><searchLink fieldCode="AR" term="%22Belokurov%2C+Vasily%22">Belokurov, Vasily</searchLink><br /><searchLink fieldCode="AR" term="%22Evans%2C+N%2E+Wyn%22">Evans, N. Wyn</searchLink><br /><searchLink fieldCode="AR" term="%22Sanders%2C+Jason+L%2E%22">Sanders, Jason L.</searchLink><br /><searchLink fieldCode="AR" term="%22Lu%2C+Yuxi%22">Lu, Yuxi</searchLink><br /><searchLink fieldCode="AR" term="%22Cao%2C+Chengye%22">Cao, Chengye</searchLink><br /><searchLink fieldCode="AR" term="%22Myeong%2C+GyuChul%22">Myeong, GyuChul</searchLink><br /><searchLink fieldCode="AR" term="%22Dillamore%2C+Adam+M%2E%22">Dillamore, Adam M.</searchLink><br /><searchLink fieldCode="AR" term="%22Kane%2C+Sarah+G%2E%22">Kane, Sarah G.</searchLink><br /><searchLink fieldCode="AR" term="%22Li%2C+Zhao-Yu%22">Li, Zhao-Yu</searchLink>
– Name: DatePubCY
  Label: Publication Year
  Group: Date
  Data: 2025
– Name: Subset
  Label: Collection
  Group: HoldingsInfo
  Data: Astrophysics
– Name: Subject
  Label: Subject Terms
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22Astrophysics+-+Astrophysics+of+Galaxies%22">Astrophysics - Astrophysics of Galaxies</searchLink>
– Name: Abstract
  Label: Description
  Group: Ab
  Data: Radial migration is an important dynamical effect that has reshaped the Galactic disc, but its origin has yet to be elucidated. In this work, we present evidence that resonant dragging by the corotation of a decelerating bar could be the main driver of radial migration in the Milky Way disc. Using a test particle simulation, we demonstrate this scenario explains the two distinct age-metallicity sequences observed in the solar vicinity: the plateauing upper sequence is interpreted as stars dragged outwards by the expanding corotation of the decelerating bar and the steeper lower sequence as stars formed locally around the solar circle. The upper migrated sequence dominates at guiding radii around the current corotation radius of the bar, $R\sim7\,\mathrm{kpc}$, but rapidly dies away beyond this where the mechanism cannot operate. This behaviour naturally explains the radial dependence of the $\mathrm{[\alpha/Fe]}$-bimodality, in particular the truncation of the high-$\mathrm{[\alpha/Fe]}$ disc beyond the solar circle. Under our proposed radial migration scenario, we constrain the Milky Way bar's pattern speed evolution using the age-metallicity distribution of stars currently trapped at corotation. We find the bar likely formed with an initial pattern speed of $60-100$ km s$^{-1}$ kpc$^{-1}$ and began decelerating $6-8$ Gyr ago at a rate $-\dot{\Omega}/\Omega^2\sim0.0025-0.0040$ (where the quoted ranges include systematic uncertainties).<br />Comment: 17 pages, 4 figures, 4 appendices, Accepted by ApJL, https://doi.org/10.3847/2041-8213/adc261
– Name: TypeDocument
  Label: Document Type
  Group: TypDoc
  Data: Working Paper
– Name: DOI
  Label: DOI
  Group: ID
  Data: 10.3847/2041-8213/adc261
– Name: URL
  Label: Access URL
  Group: URL
  Data: <link linkTarget="URL" linkTerm="http://arxiv.org/abs/2502.02642" linkWindow="_blank">http://arxiv.org/abs/2502.02642</link>
– Name: AN
  Label: Accession Number
  Group: ID
  Data: edsarx.2502.02642
PLink https://login.libproxy.scu.edu/login?url=https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&scope=site&db=edsarx&AN=edsarx.2502.02642
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.3847/2041-8213/adc261
    Subjects:
      – SubjectFull: Astrophysics - Astrophysics of Galaxies
        Type: general
    Titles:
      – TitleFull: Observational Constraints of Radial Migration in the Galactic Disc Driven by the Slowing Bar
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Zhang, HanYuan
      – PersonEntity:
          Name:
            NameFull: Belokurov, Vasily
      – PersonEntity:
          Name:
            NameFull: Evans, N. Wyn
      – PersonEntity:
          Name:
            NameFull: Sanders, Jason L.
      – PersonEntity:
          Name:
            NameFull: Lu, Yuxi
      – PersonEntity:
          Name:
            NameFull: Cao, Chengye
      – PersonEntity:
          Name:
            NameFull: Myeong, GyuChul
      – PersonEntity:
          Name:
            NameFull: Dillamore, Adam M.
      – PersonEntity:
          Name:
            NameFull: Kane, Sarah G.
      – PersonEntity:
          Name:
            NameFull: Li, Zhao-Yu
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 04
              M: 02
              Type: published
              Y: 2025
ResultId 1