| Download | - View supplementary information: The Pristine Inner Galaxy Survey (PIGS) I: tracing the kinematics of metal-poor stars in the Galactic bulge (PDF, 624 KiB)
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| DOI | Resolve DOI: https://doi.org/10.1093/mnrasl/slz156 |
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| Author | Search for: Arentsen, A.ORCID identifier: https://orcid.org/0000-0002-0544-2217; Search for: Starkenburg, E.; Search for: Martin, N. F.; Search for: Hill, V.; Search for: Ibata, R.; Search for: Kunder, A.; Search for: Schultheis, M.; Search for: Venn, K. A.ORCID identifier: https://orcid.org/0000-0003-4134-2042; Search for: Zucker, D. B.; Search for: Aguado, D.; Search for: Carlberg, R.; Search for: González Hernández, J. I.; Search for: Lardo, C.ORCID identifier: https://orcid.org/0000-0002-4295-8773; Search for: Longeard, N.; Search for: Malhan, K.; Search for: Navarro, J. F.; Search for: Sánchez-Janssen, R.ORCID identifier: https://orcid.org/0000-0003-4945-0056; Search for: Sestito, F.; Search for: Thomas, G.1; Search for: Youakim, K.ORCID identifier: https://orcid.org/0000-0002-2625-9825; Search for: Lewis, G. F.ORCID identifier: https://orcid.org/0000-0003-3081-9319; Search for: Simpson, J. D.ORCID identifier: https://orcid.org/0000-0002-8165-2507; Search for: Wan, Z.ORCID identifier: https://orcid.org/0000-0002-3105-3821 |
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| Affiliation | - National Research Council of Canada. Herzberg Astronomy and Astrophysics
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| Format | Text, Article |
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| Subject | Galaxy: bulge; Galaxy: evolution; Galaxy: formation; Galaxy: halo; Galaxy: kinematics and dynamics; Galaxy: structure |
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| Abstract | Our Galaxy is known to contain a central boxy/peanut-shaped bulge, yet the importance of a classical, pressure-supported component within the central part of the Milky Way is still being debated. It should be most visible at low metallicity, a regime that has not yet been studied in detail. Using metallicity-sensitive narrow-band photometry, the Pristine Inner Galaxy Survey (PIGS) has collected a large sample of metal-poor ([Fe/H]<-1.0) stars in the inner Galaxy to address this open question. We use PIGS to trace the metal-poor inner Galaxy kinematics as function of metallicity for the first time. We find that the rotational signal decreases with decreasing [Fe/H] , until it becomes negligible for the most metal-poor stars. Additionally, the velocity dispersion increases with decreasing metallicity for -3.0 <[Fe/H]<-0.5, with a gradient of −44 ± 4 km s⁻¹ dex⁻¹. These observations may signal a transition between Galactic components of different metallicities and kinematics, a different mapping on to the boxy/peanut-shaped bulge for former disc stars of different metallicities and/or the secular dynamical and gravitational influence of the bar on the pressure-supported component. Our results provide strong constraints on models that attempt to explain the properties of the inner Galaxy. |
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| Publication date | 2019-10-18 |
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| Publisher | Oxford University Press
Royal Astronomical Society |
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| Language | English |
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| Peer reviewed | Yes |
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| Export citation | Export as RIS |
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| Report a correction | Report a correction (opens in a new tab) |
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| Record identifier | b3d11716-8d5f-4c28-a108-e6b12490795b |
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| Record created | 2020-10-30 |
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| Record modified | 2020-11-09 |
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