Academic Journal
Fundamental relations for the velocity dispersion of stars in the Milky Way
| العنوان: | Fundamental relations for the velocity dispersion of stars in the Milky Way |
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| المؤلفون: | Sharma, S, Hayden, MR, Bland-Hawthorn, J, Stello, D, Buder, S, Zinn, JC, Kallinger, T, Asplund, M, De Silva, GM, D'Orazi, V, Freeman, K, Kos, J, Lewis, GF, Lin, J, Lind, K, Martell, S, Simpson, JD, Wittenmyer, RA, Zucker, DB, Zwitter, T, Chen, B, Cotar, K, Esdaile, J, Hon, M, Horner, J, Huber, D, Kafle, PR, Khanna, S, Ting, YS, Nataf, DM, Nordlander, T, Saadon, MHM, Tepper-Garcia, T, Tinney, CG, Traven, G, Watson, F, Wright, D, Wyse, RFG |
| المصدر: | urn:ISSN:0035-8711 ; urn:ISSN:1365-2966 ; Monthly Notices of the Royal Astronomical Society, 506, 2, 1761-1776 |
| بيانات النشر: | Oxford University Press |
| سنة النشر: | 2021 |
| المجموعة: | UNSW Sydney (The University of New South Wales): UNSWorks |
| مصطلحات موضوعية: | 5101 Astronomical Sciences, 51 Physical Sciences, anzsrc-for: 5101 Astronomical Sciences, anzsrc-for: 51 Physical Sciences, anzsrc-for: 0201 Astronomical and Space Sciences, anzsrc-for: 5107 Particle and high energy physics, anzsrc-for: 5109 Space sciences |
| الوصف: | We explore the fundamental relations governing the radial and vertical velocity dispersions of stars in the Milky Way, from combined studies of complementary surveys including GALAH, LAMOST, APOGEE, the NASA Kepler and K2 missions, and Gaia DR2. We find that different stellar samples, even though they target different tracer populations and employ a variety of age estimation techniques, follow the same set of fundamental relations. We provide the clearest evidence to date that, in addition to the well-known dependence on stellar age, the velocity dispersions of stars depend on orbital angular momentum Lz, metallicity, and height above the plane |z|, and are well described by a multiplicatively separable functional form. The dispersions have a power-law dependence on age with exponents of 0.441 ± 0.007 and 0.251 ± 0.006 for σz and σR, respectively, and the power law is valid even for the oldest stars. For the solar neighbourhood stars, the apparent break in the power law for older stars, as seen in previous studies, is due to the anticorrelation of Lz with age. The dispersions decrease with increasing Lz until we reach the Sun's orbital angular momentum, after which σz increases (implying flaring in the outer disc) while σR flattens. For a given age, the dispersions increase with decreasing metallicity, suggesting that the dispersions increase with birth radius. The dispersions also increase linearly with |z|. The same set of relations that work in the solar neighbourhood also work for stars between 3 < R/kpc < 20. Finally, the high-[α/Fe] stars follow the same relations as the low-[α/Fe] stars. |
| نوع الوثيقة: | article in journal/newspaper |
| وصف الملف: | application/pdf |
| اللغة: | unknown |
| Relation: | http://hdl.handle.net/1959.4/unsworks_71269; https://doi.org/10.1093/mnras/stab1086 |
| DOI: | 10.1093/mnras/stab1086 |
| الاتاحة: | http://hdl.handle.net/1959.4/unsworks_71269 https://unsworks.unsw.edu.au/bitstreams/7b1c99b4-fc1c-400b-aee7-38b0c98fcb2d/download https://doi.org/10.1093/mnras/stab1086 |
| Rights: | open access ; https://purl.org/coar/access_right/c_abf2 ; CC-BY-NC-ND ; https://creativecommons.org/licenses/by-nc-nd/4.0/ ; free_to_read ; This article has been accepted for publication in the Monthly Notices of the Royal Astronomical Society ©: 2021 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. https://doi.org/ 10.1093/mnras/stab1086 |
| رقم الانضمام: | edsbas.E0161F25 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1093/mnras/stab1086 |
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