NAOC Open IR
Dynamical Relics of the Ancient Galactic Halo
Yuan, Zhen1; Myeong, G. C.2,3; Beers, Timothy C.4,5; Evans, N. W.3; Lee, Young Sun6; Banerjee, Projjwal7; Gudin, Dmitrii4,5; Hattori, Kohei8; Li, Haining9; Matsuno, Tadafumi10,11; Placco, Vinicius M.4,5; Smith, M. C.1; Whitten, Devin D.4,5; Zhao, Gang9,12
2020-03-01
Source PublicationASTROPHYSICAL JOURNAL
ISSN0004-637X
Volume891Issue:1Pages:17
AbstractWe search for dynamical substructures in the LAMOST DR3 very metal-poor (VMP) star catalog. After cross-matching with Gaia DR2, there are similar to 3300 VMP stars with available high-quality astrometric information that have halo-like kinematics. We apply a method based on the self-organizing map StarGO to find groups clustered in the 4D space of orbital energy and angular momentum. We identify 57 dynamically tagged groups (DTGs), which we label DTG-1 to DTG-57. Most of them belong to existing massive substructures in the nearby halo, such as the Gaia Sausage or Sequoia. The stream identified by Helmi et al. is recovered, but the two disjointed portions of the substructure appear to have distinct dynamical properties. The very retrograde substructure Rg5 found previously by Myeong et al. is also retrieved. We report six new DTGs with highly retrograde orbits, two with very prograde orbits, and 12 with polar orbits. By mapping other data sets (APOGEE halo stars, and catalogs of r-process-enhanced and carbon-enhanced metal-poor [CEMP] stars) onto the trained neuron map, we can associate stars with detailed chemical abundances with the DTGs and look for associations with chemically peculiar stars. The highly eccentric Gaia Sausage groups contain representatives of both debris from the satellite itself (which is alpha-poor) and the Splashed Disk, sent up into eccentric halo orbits from the encounter (and which is alpha-rich). The new prograde substructures also appear to be associated with the Splashed Disk. The DTGs belonging to the Gaia Sausage host two relatively metal-rich r-II stars and six CEMP stars in different subclasses, consistent with the idea that the Gaia Sausage progenitor is a massive dwarf galaxy. Rg5 is dynamically associated with two highly r-process-enhanced stars with [Fe/H] similar to -3. This finding indicates that its progenitor might be an ultrafaint dwarf galaxy that has experienced r-process enrichment from neutron star mergers.
KeywordMilky Way stellar halo Milky Way formation R-process
Funding OrganizationNational Key Basic Research and Development Program of China ; National Key Basic Research and Development Program of China ; Heising-Simons Foundation ; Heising-Simons Foundation ; National Science Foundation ; National Science Foundation ; Special Funding for Advanced Users through LAMOST FELLOWSHIP ; Special Funding for Advanced Users through LAMOST FELLOWSHIP ; Shanghai Sailing Program ; Shanghai Sailing Program ; NSFC ; NSFC ; CfA Fellowship ; CfA Fellowship ; National Research Foundation (NRF) of Korea - Ministry of Science and ICT ; National Research Foundation (NRF) of Korea - Ministry of Science and ICT ; National Key R&D Program of China ; National Key R&D Program of China ; National Key Basic Research and Development Program of China ; National Key Basic Research and Development Program of China ; Heising-Simons Foundation ; Heising-Simons Foundation ; National Science Foundation ; National Science Foundation ; Special Funding for Advanced Users through LAMOST FELLOWSHIP ; Special Funding for Advanced Users through LAMOST FELLOWSHIP ; Shanghai Sailing Program ; Shanghai Sailing Program ; NSFC ; NSFC ; CfA Fellowship ; CfA Fellowship ; National Research Foundation (NRF) of Korea - Ministry of Science and ICT ; National Research Foundation (NRF) of Korea - Ministry of Science and ICT ; National Key R&D Program of China ; National Key R&D Program of China ; National Key Basic Research and Development Program of China ; National Key Basic Research and Development Program of China ; Heising-Simons Foundation ; Heising-Simons Foundation ; National Science Foundation ; National Science Foundation ; Special Funding for Advanced Users through LAMOST FELLOWSHIP ; Special Funding for Advanced Users through LAMOST FELLOWSHIP ; Shanghai Sailing Program ; Shanghai Sailing Program ; NSFC ; NSFC ; CfA Fellowship ; CfA Fellowship ; National Research Foundation (NRF) of Korea - Ministry of Science and ICT ; National Research Foundation (NRF) of Korea - Ministry of Science and ICT ; National Key R&D Program of China ; National Key R&D Program of China ; National Key Basic Research and Development Program of China ; National Key Basic Research and Development Program of China ; Heising-Simons Foundation ; Heising-Simons Foundation ; National Science Foundation ; National Science Foundation ; Special Funding for Advanced Users through LAMOST FELLOWSHIP ; Special Funding for Advanced Users through LAMOST FELLOWSHIP ; Shanghai Sailing Program ; Shanghai Sailing Program ; NSFC ; NSFC ; CfA Fellowship ; CfA Fellowship ; National Research Foundation (NRF) of Korea - Ministry of Science and ICT ; National Research Foundation (NRF) of Korea - Ministry of Science and ICT ; National Key R&D Program of China ; National Key R&D Program of China
DOI10.3847/1538-4357/ab6ef7
WOS KeywordMETAL-POOR STARS ; DIGITAL SKY SURVEY ; ACCRETED STELLAR HALO ; MILKY-WAY ; MAIN-SEQUENCE ; OMEGA-CENTAURI ; ELEMENT-RICH ; DWARF GALAXY ; SAGITTARIUS ; ABUNDANCES
Language英语
Funding ProjectNational Key Basic Research and Development Program of China[2018YFA0404501] ; Heising-Simons Foundation ; National Science Foundation[NSF PHY-1748958] ; Special Funding for Advanced Users through LAMOST FELLOWSHIP ; Shanghai Sailing Program[Y955051001] ; NSFC[11988101] ; NSFC[11573032] ; NSFC[11973049] ; NSFC[11890694] ; NSFC[11673083] ; CfA Fellowship ; National Research Foundation (NRF) of Korea - Ministry of Science and ICT[2017R1A5A1070354] ; National Research Foundation (NRF) of Korea - Ministry of Science and ICT[NRF-2018R1A2B6003961] ; National Key R&D Program of China[2019YFA0405502] ; [18J11326]
Funding OrganizationNational Key Basic Research and Development Program of China ; National Key Basic Research and Development Program of China ; Heising-Simons Foundation ; Heising-Simons Foundation ; National Science Foundation ; National Science Foundation ; Special Funding for Advanced Users through LAMOST FELLOWSHIP ; Special Funding for Advanced Users through LAMOST FELLOWSHIP ; Shanghai Sailing Program ; Shanghai Sailing Program ; NSFC ; NSFC ; CfA Fellowship ; CfA Fellowship ; National Research Foundation (NRF) of Korea - Ministry of Science and ICT ; National Research Foundation (NRF) of Korea - Ministry of Science and ICT ; National Key R&D Program of China ; National Key R&D Program of China ; National Key Basic Research and Development Program of China ; National Key Basic Research and Development Program of China ; Heising-Simons Foundation ; Heising-Simons Foundation ; National Science Foundation ; National Science Foundation ; Special Funding for Advanced Users through LAMOST FELLOWSHIP ; Special Funding for Advanced Users through LAMOST FELLOWSHIP ; Shanghai Sailing Program ; Shanghai Sailing Program ; NSFC ; NSFC ; CfA Fellowship ; CfA Fellowship ; National Research Foundation (NRF) of Korea - Ministry of Science and ICT ; National Research Foundation (NRF) of Korea - Ministry of Science and ICT ; National Key R&D Program of China ; National Key R&D Program of China ; National Key Basic Research and Development Program of China ; National Key Basic Research and Development Program of China ; Heising-Simons Foundation ; Heising-Simons Foundation ; National Science Foundation ; National Science Foundation ; Special Funding for Advanced Users through LAMOST FELLOWSHIP ; Special Funding for Advanced Users through LAMOST FELLOWSHIP ; Shanghai Sailing Program ; Shanghai Sailing Program ; NSFC ; NSFC ; CfA Fellowship ; CfA Fellowship ; National Research Foundation (NRF) of Korea - Ministry of Science and ICT ; National Research Foundation (NRF) of Korea - Ministry of Science and ICT ; National Key R&D Program of China ; National Key R&D Program of China ; National Key Basic Research and Development Program of China ; National Key Basic Research and Development Program of China ; Heising-Simons Foundation ; Heising-Simons Foundation ; National Science Foundation ; National Science Foundation ; Special Funding for Advanced Users through LAMOST FELLOWSHIP ; Special Funding for Advanced Users through LAMOST FELLOWSHIP ; Shanghai Sailing Program ; Shanghai Sailing Program ; NSFC ; NSFC ; CfA Fellowship ; CfA Fellowship ; National Research Foundation (NRF) of Korea - Ministry of Science and ICT ; National Research Foundation (NRF) of Korea - Ministry of Science and ICT ; National Key R&D Program of China ; National Key R&D Program of China
WOS Research AreaAstronomy & Astrophysics
WOS SubjectAstronomy & Astrophysics
WOS IDWOS:000518955700001
PublisherIOP PUBLISHING LTD
Citation statistics
Document Type期刊论文
Identifierhttp://ir.bao.ac.cn/handle/114a11/54357
Collection中国科学院国家天文台
Corresponding AuthorYuan, Zhen
Affiliation1.Chinese Acad Sci, Shanghai Astron Observ, Key Lab Res Galaxies & Cosmol, 80 Nandan Rd, Shanghai 200030, Peoples R China
2.Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA
3.Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England
4.Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA
5.JINA Ctr Evolut Elements, E Lansing, MI USA
6.Chungnam Natl Univ, Dept Astron & Space Sci, Daejeon 34134, South Korea
7.Indian Inst Technol Palakkad, Dept Phys, Palakkad 678557, Kerala, India
8.Carnegie Mellon Univ, Dept Phys, 5000 Forbes Ave, Pittsburgh, PA 15213 USA
9.Chinese Acad Sci, Natl Astron Observ, Key Lab Opt Astron, A20 Datun Rd, Beijing 100102, Peoples R China
10.SOKENDAI Grad Univ Adv Studies, Sch Phys Sci, Dept Astron Sci, Mitaka, Tokyo 1818588, Japan
11.Natl Astron Observ Japan, 2-21-1 Osawa, Mitaka, Tokyo 1818588, Japan
12.Univ Chinese Acad Sci, Sch Astron & Space Sci, 19A Yuquan Rd, Beijing 100049, Peoples R China
Recommended Citation
GB/T 7714
Yuan, Zhen,Myeong, G. C.,Beers, Timothy C.,et al. Dynamical Relics of the Ancient Galactic Halo[J]. ASTROPHYSICAL JOURNAL,2020,891(1):17.
APA Yuan, Zhen.,Myeong, G. C..,Beers, Timothy C..,Evans, N. W..,Lee, Young Sun.,...&Zhao, Gang.(2020).Dynamical Relics of the Ancient Galactic Halo.ASTROPHYSICAL JOURNAL,891(1),17.
MLA Yuan, Zhen,et al."Dynamical Relics of the Ancient Galactic Halo".ASTROPHYSICAL JOURNAL 891.1(2020):17.
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