| 1. |
- Bensby, T., et al.
(författare)
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Disentangling the Hercules stream
- 2007
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 655:2, s. 89-92
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Tidskriftsartikel (refereegranskat)abstract
- Using high-resolution spectra of nearby F and G dwarf stars, we have investigated the detailed abundance and age structure of the Hercules stream. We find that the stars in the stream have a wide range of stellar ages, metallicities, and element abundances. By comparing to existing samples of stars in the solar neighborhood with kinematics typical of the Galactic thin and thick disks, we find that the properties of the Hercules stream distinctly separate into the abundance and age trends of the two disks. Hence, we find it unlikely that the Hercules stream is a unique Galactic stellar population but rather is a mixture of thin and thick disk stars. This points toward a dynamical origin for the Hercules stream, probably caused by the Galactic bar.
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| 2. |
- Bensby, T., et al.
(författare)
-
Tracing the Galactic Thick Disk to Solar Metallicities
- 2007
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 663:1, s. 13-16
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Tidskriftsartikel (refereegranskat)abstract
- We show that the Galactic thick disk reaches at least solar metallicities and that it experienced strong chemical enrichment during a period of ~3 Gyr, ending around 8-9 Gyr ago. This finding puts further constraints on the relation and interface between the thin and thick disks and their formation processes. Our results are based on a detailed elemental abundance analysis of 261 kinematically selected F and G dwarf stars in the solar neighborhood: 194 likely members of the thick disk and 67 likely members of the thin disk, in the range -1.3<~[Fe/H]<~+0.4. Based on data collected with the 6.5 m Magellan telescopes at the Las Campanas Observatory and with the Very Large Telescope at the European Southern Observatory (ESO proposal 72.B-0179).
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| 3. |
- Bensby, T., et al.
(författare)
-
The Nature of the Metal-Rich Thick Disk
- 2007
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Ingår i: ASP Conference Proceedings. - 9781583813096 ; 374, s. 181-186
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Konferensbidrag (refereegranskat)abstract
- We have traced the Galactic thick disk to its, to date, highest metallicities. Based on high-resolution spectroscopic observations of 187 F and G dwarf stars that kinematically can be associated either with the thin disk (60 stars) or with the thick disk (127 stars), we find that the thick disk stars reach at least solar metallicities, and maybe even higher. This finding is independent of the U_LSR, V_LSR and W_LSR velocities of the stars.
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| 4. |
- Oey, M.S., et al.
(författare)
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The Origin of the Hercules Stream
- 2007
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Ingår i: Bulletin of the American Astronomical Society. ; 39:1, s. 194-194
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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