Orbital Evidences for Dark-matter-free Milky Way Dwarf Spheroidal Galaxies
文献类型：期刊论文
| 作者 | Hammer, Francois1; Yang, Yanbin1; Arenou, Frederic1; Wang, Jianling2; Li, Hefan1,3; Bonifacio, Piercarlo1; Babusiaux, Carine1 |
| 刊名 | ASTROPHYSICAL JOURNAL
 |
| 出版日期 | 2020-03-20 |
| 卷号 | 892期号:1页码:12 |
| 关键词 | Dwarf spheroidal galaxies Dwarf galaxies Observational cosmology Dark matter Galaxy rotation curves Circumgalactic medium Milky Way Galaxy Magellanic Clouds Magellanic Stream Local Group |
| ISSN号 | 0004-637X |
| DOI | 10.3847/1538-4357/ab77be |
| 英文摘要 | The nature of Milky Way dwarf spheroidals (MW dSphs) has been questioned, in particular whether they are dominated by dark matter (DM). Here we investigate an alternative scenario, for which tidal shocks are exerted by the MW to DM-free dSphs after a first infall of their gas-rich progenitors, and for which theoretical calculations have been verified by pure N-body simulations. Whether or not the dSphs are on their first infall cannot be resolved on the sole basis of their star formation history. In fact, gas removal may cause complex gravitational instabilities, and near-pericenter passages can give rise to tidal disruptive processes. Advanced precision with the Gaia satellite in determining both their past orbital motions and the MW velocity curve is, however, providing crucial results. First, tidal shocks explain why DM-free dSphs are found preferentially near their pericenter, where they are in a destructive process, while their chance to be long-lived satellites is associated with a very low probability P similar to 2 x 10(-7), which is at odds with the current DM-dominated dSph scenario. Second, most dSph binding energies are consistent with a first infall. Third, the MW tidal shocks that predict the observed dSph velocity dispersions are themselves predicted in amplitude by the most accurate MW velocity curve. Fourth, tidal shocks accurately predict the forces or accelerations exerted at half-light radii of dSphs, including the MW and the Magellanic System gravitational attractions. The above is suggestive of dSphs that are DM-free and tidally shocked near their pericenters, which may provoke a significant quake in our understanding of near-field cosmology. |
| WOS关键词 | SATELLITE GALAXIES ; RAM PRESSURE ; THIN PLANE ; DYNAMICS ; DISCOVERY ; POPULATION ; DISPERSION ; EVOLUTION ; CLUSTERS ; ACCURATE |
| 资助项目 | Region Ile de France ; project Equip at Meso of the Programme Investissements d Avenir[ANR-10-EQPX-29-01] |
| WOS研究方向 | Astronomy & Astrophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000521416300001 |
| 出版者 | IOP PUBLISHING LTD |
| 资助机构 | Region Ile de France ; Region Ile de France ; project Equip at Meso of the Programme Investissements d Avenir ; project Equip at Meso of the Programme Investissements d Avenir ; Region Ile de France ; Region Ile de France ; project Equip at Meso of the Programme Investissements d Avenir ; project Equip at Meso of the Programme Investissements d Avenir ; Region Ile de France ; Region Ile de France ; project Equip at Meso of the Programme Investissements d Avenir ; project Equip at Meso of the Programme Investissements d Avenir ; Region Ile de France ; Region Ile de France ; project Equip at Meso of the Programme Investissements d Avenir ; project Equip at Meso of the Programme Investissements d Avenir |
| 源URL | [http://ir.bao.ac.cn/handle/114a11/55411]  |
| 专题 | 中国科学院国家天文台 |
| 通讯作者 | Hammer, Francois |
| 作者单位 | 1.Univ PSL, Observ Paris, CNRS, GEPI, Pl Jules Janssen, F-92195 Meudon, France 2.Chinese Acad Sci, NAOC, A20 Datun Rd, Beijing 100012, Peoples R China 3.Univ Chinese Acad Sci, Sch Phys Sci, Beijing 100049, Peoples R China |
| 推荐引用方式 GB/T 7714 | Hammer, Francois,Yang, Yanbin,Arenou, Frederic,et al. Orbital Evidences for Dark-matter-free Milky Way Dwarf Spheroidal Galaxies[J]. ASTROPHYSICAL JOURNAL,2020,892(1):12. |
| APA | Hammer, Francois.,Yang, Yanbin.,Arenou, Frederic.,Wang, Jianling.,Li, Hefan.,...&Babusiaux, Carine.(2020).Orbital Evidences for Dark-matter-free Milky Way Dwarf Spheroidal Galaxies.ASTROPHYSICAL JOURNAL,892(1),12. |
| MLA | Hammer, Francois,et al."Orbital Evidences for Dark-matter-free Milky Way Dwarf Spheroidal Galaxies".ASTROPHYSICAL JOURNAL 892.1(2020):12. |
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来源：国家天文台
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