Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Asymmetric metallicity patterns in the stellar velocity space with RAVE
Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC). Université de Strasbourg, France.
Show others and affiliations
Number of Authors: 18
2017 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 601, A59Article in journal (Refereed) Published
Abstract [en]

Context. The chemical abundances of stars encode information on their place and time of origin. Stars formed together in e.g. a cluster, should present chemical homogeneity. Also disk stars influenced by the effects of the bar and the spiral arms might have distinct chemical signatures depending on the type of orbit that they follow, e.g. from the inner versus outer regions of the Milky Way.

Aims. We explore the correlations between velocity and metallicity and the possible distinct chemical signatures of the velocity over-densities of the local Galactic neighbourhood.

Methods. We use the large spectroscopic survey RAVE and the Geneva Copenhagen Survey. We compare the metallicity distribution of regions in the velocity plane (upsilon(R), upsilon(phi)) with that of their symmetric counterparts (-upsilon(R), upsilon(phi)). We expect similar metallicity distributions if there are no tracers of a sub-population (e.g. a dispersed cluster, accreted stars), if the disk of the Galaxy is axisymmetric, and if the orbital effects of the bar and the spiral arms are weak.

Results. We find that the metallicity-velocity space of the solar neighbourhood is highly patterned. A large fraction of the velocity plane shows differences in the metallicity distribution when comparing symmetric upsilon(R) regions. The typical differences in the median metallicity are of 0 : 05 dex with statistical significant of at least 95% confidence, and with values up to 0 : 6 dex. For stars with low azimuthal velocity v(phi), the ones moving outwards. These include stars in the Hercules and Hyades moving groups and other velocity branch-like structures. For higher v(phi), the stars moving inwards have higher metallicity than those moving outwards. We have also discovered a positive gradient in v(phi) with resp ect to metallicity at high metallicities, apart from the two known positive and negative gradients for the thick and thin disks.

Conclusions. The most likely interpretation of the metallicity asymmetry is that it is mainly due to the orbital effects of the Galactic bar and the radial metallicity gradient of the disk. We present a simulation that supports this idea.

Place, publisher, year, edition, pages
2017. Vol. 601, A59
Keyword [en]
Galaxy: kinematics and dynamics, Galaxy: structure, Galaxy: disk, Galaxy: evolution, Galaxy: abundances
National Category
Physical Sciences
Identifiers
URN: urn:nbn:se:su:diva-144852DOI: 10.1051/0004-6361/201629387ISI: 000402313500059OAI: oai:DiVA.org:su-144852DiVA: diva2:1118489
Available from: 2017-06-30 Created: 2017-06-30 Last updated: 2017-06-30Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Monari, Giacomo
By organisation
Department of PhysicsThe Oskar Klein Centre for Cosmo Particle Physics (OKC)
In the same journal
Astronomy and Astrophysics
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar

Altmetric score

Total: 3 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf