دورية أكاديمية
Gaia EDR3 proper motions of Milky Way dwarfs. II: Velocities, Total Energy and Angular Momentum
| العنوان: | Gaia EDR3 proper motions of Milky Way dwarfs. II: Velocities, Total Energy and Angular Momentum |
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| المؤلفون: | Hammer, François, Wang, Jianling, Pawlowski, Marcel, Yang, Yanbin, Bonifacio, Piercarlo, Li, Hefan, Babusiaux, Carine, Arenou, Frédéric |
| المساهمون: | Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), National Astronomical Observatories Beijing (NAOC), Chinese Academy of Sciences Beijing (CAS), Leibniz Institute for Astrophysics Potsdam (AIP), University of Chinese Academy of Sciences Beijing (UCAS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales Toulouse (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA) |
| المصدر: | ISSN: 0004-637X. |
| بيانات النشر: | HAL CCSD American Astronomical Society |
| سنة النشر: | 2021 |
| المجموعة: | Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
| مصطلحات موضوعية: | [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] |
| الوصف: | 17 pages, 12 Figures, 1 Table, accepted in The Astrophysical Journal, 2021, September 15; Subtitle: "Are Milky Way dwarfs at first infall?" ; International audience ; Here we show that precise Gaia EDR3 proper motions have provided robust estimates of 3D velocities, angular momentum and total energy for 40 Milky Way dwarfs. The results are statistically robust and are independent of the Milky Way mass profile. Dwarfs do not behave like long-lived satellites of the Milky Way because of their excessively large velocities, angular momenta, and total energies. Comparing them to other MW halo population, we find that many are at first passage, $\le$ 2 Gyr ago, i.e., more recently than the passage of Sagittarius, $\sim$ 4-5 Gyr ago. We suggest that this is in agreement with the stellar populations of all dwarfs, for which we find that a small fraction of young stars cannot be excluded. We also find that dwarf radial velocities contribute too little to their kinetic energy when compared to satellite systems with motions only regulated by gravity, and some other mechanism must be at work such as ram pressure. The latter may have preferentially reduced radial velocities when dwarf progenitors entered the halo until they lost their gas. It could also explain why most dwarfs lie near their pericenter. We also discover a novel large scale structure perpendicular to the Milky Way disk, which is made by 20% of dwarfs orbiting or counter orbiting with the Sagittarius dwarf. |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| العلاقة: | info:eu-repo/semantics/altIdentifier/arxiv/2109.11557; obspm-03364434; https://hal-obspm.ccsd.cnrs.fr/obspm-03364434Test; ARXIV: 2109.11557 |
| DOI: | 10.3847/1538-4357/ac27a8 |
| الإتاحة: | https://doi.org/10.3847/1538-4357/ac27a8Test https://hal-obspm.ccsd.cnrs.fr/obspm-03364434Test |
| رقم الانضمام: | edsbas.2D385BE4 |
| قاعدة البيانات: | BASE |
| DOI: | 10.3847/1538-4357/ac27a8 |
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