The first tidally disrupted ultra-faint dwarf galaxy? : a spectroscopic analysis of the Tucana III stream
Autor(a) principal: | |
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Data de Publicação: | 2018 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFRGS |
Texto Completo: | http://hdl.handle.net/10183/187864 |
Resumo: | We present a spectroscopic study of the tidal tails and core of the Milky Way satellite Tucana III, collectively referred to as the Tucana III stream, using the 2dF+AAOmega spectrograph on the Anglo-Australian Telescope and the IMACS spectrograph on the Magellan Baade Telescope. In addition to recovering the brightest nine previously known member stars in the Tucana III core, we identify 22 members in the tidal tails.We observe strong evidence for a velocity gradient of 8.0 0.4 km s-1 deg-1 over at least 3° on the sky. Based on the continuity in velocity, we confirm that the Tucana III tails are real tidal extensions of Tucana III. The large velocity gradient of the stream implies that Tucana III is likely on a radial orbit. We successfully obtain metallicities for four members in the core and 12 members in the tails. We find that members close to the ends of the stream tend to be more metal-poor than members in the core, indicating a possible metallicity gradient between the center of the progenitor halo and its edge. The spread in metallicity suggests that the progenitor of the Tucana III stream is likely a dwarf galaxy rather than a star cluster. Furthermore, we find that with the precise photometry of the Dark Energy Survey data, there is a discernible color offset between metal-rich disk stars and metal-poor stream members. This metallicity-dependent color offers a more efficient method to recognize metal-poor targets and will increase the selection efficiency of stream members for future spectroscopic follow-up programs on stellar streams. |
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Li, T. S.Santiago, Basilio XavierDES Collaboration2019-01-18T02:31:25Z20180004-637Xhttp://hdl.handle.net/10183/187864001083049We present a spectroscopic study of the tidal tails and core of the Milky Way satellite Tucana III, collectively referred to as the Tucana III stream, using the 2dF+AAOmega spectrograph on the Anglo-Australian Telescope and the IMACS spectrograph on the Magellan Baade Telescope. In addition to recovering the brightest nine previously known member stars in the Tucana III core, we identify 22 members in the tidal tails.We observe strong evidence for a velocity gradient of 8.0 0.4 km s-1 deg-1 over at least 3° on the sky. Based on the continuity in velocity, we confirm that the Tucana III tails are real tidal extensions of Tucana III. The large velocity gradient of the stream implies that Tucana III is likely on a radial orbit. We successfully obtain metallicities for four members in the core and 12 members in the tails. We find that members close to the ends of the stream tend to be more metal-poor than members in the core, indicating a possible metallicity gradient between the center of the progenitor halo and its edge. The spread in metallicity suggests that the progenitor of the Tucana III stream is likely a dwarf galaxy rather than a star cluster. Furthermore, we find that with the precise photometry of the Dark Energy Survey data, there is a discernible color offset between metal-rich disk stars and metal-poor stream members. This metallicity-dependent color offers a more efficient method to recognize metal-poor targets and will increase the selection efficiency of stream members for future spectroscopic follow-up programs on stellar streams.application/pdfengThe astrophysical journal. Bristol. Vol. 866, no. 1 (Oct. 2018), 22, 23 p.Galáxias anãsMatéria escuraMetalicidadeDark matterGalaxies: dwarfGalaxies: individual (Tucana III)Local groupStars: abundancesThe first tidally disrupted ultra-faint dwarf galaxy? : a spectroscopic analysis of the Tucana III streamEstrangeiroinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRGSinstname:Universidade Federal do Rio Grande do Sul (UFRGS)instacron:UFRGSTEXT001083049.pdf.txt001083049.pdf.txtExtracted Texttext/plain120822http://www.lume.ufrgs.br/bitstream/10183/187864/2/001083049.pdf.txt8dc86d8ed6d275c1695ea0918cb0ebe4MD52ORIGINAL001083049.pdfTexto completo (inglês)application/pdf1866467http://www.lume.ufrgs.br/bitstream/10183/187864/1/001083049.pdfb4cf83e00dfb00db65a127d1c548331cMD5110183/1878642023-07-02 03:40:53.148598oai:www.lume.ufrgs.br:10183/187864Repositório de PublicaçõesPUBhttps://lume.ufrgs.br/oai/requestopendoar:2023-07-02T06:40:53Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS)false |
dc.title.pt_BR.fl_str_mv |
The first tidally disrupted ultra-faint dwarf galaxy? : a spectroscopic analysis of the Tucana III stream |
title |
The first tidally disrupted ultra-faint dwarf galaxy? : a spectroscopic analysis of the Tucana III stream |
spellingShingle |
The first tidally disrupted ultra-faint dwarf galaxy? : a spectroscopic analysis of the Tucana III stream Li, T. S. Galáxias anãs Matéria escura Metalicidade Dark matter Galaxies: dwarf Galaxies: individual (Tucana III) Local group Stars: abundances |
title_short |
The first tidally disrupted ultra-faint dwarf galaxy? : a spectroscopic analysis of the Tucana III stream |
title_full |
The first tidally disrupted ultra-faint dwarf galaxy? : a spectroscopic analysis of the Tucana III stream |
title_fullStr |
The first tidally disrupted ultra-faint dwarf galaxy? : a spectroscopic analysis of the Tucana III stream |
title_full_unstemmed |
The first tidally disrupted ultra-faint dwarf galaxy? : a spectroscopic analysis of the Tucana III stream |
title_sort |
The first tidally disrupted ultra-faint dwarf galaxy? : a spectroscopic analysis of the Tucana III stream |
author |
Li, T. S. |
author_facet |
Li, T. S. Santiago, Basilio Xavier DES Collaboration |
author_role |
author |
author2 |
Santiago, Basilio Xavier DES Collaboration |
author2_role |
author author |
dc.contributor.author.fl_str_mv |
Li, T. S. Santiago, Basilio Xavier DES Collaboration |
dc.subject.por.fl_str_mv |
Galáxias anãs Matéria escura Metalicidade |
topic |
Galáxias anãs Matéria escura Metalicidade Dark matter Galaxies: dwarf Galaxies: individual (Tucana III) Local group Stars: abundances |
dc.subject.eng.fl_str_mv |
Dark matter Galaxies: dwarf Galaxies: individual (Tucana III) Local group Stars: abundances |
description |
We present a spectroscopic study of the tidal tails and core of the Milky Way satellite Tucana III, collectively referred to as the Tucana III stream, using the 2dF+AAOmega spectrograph on the Anglo-Australian Telescope and the IMACS spectrograph on the Magellan Baade Telescope. In addition to recovering the brightest nine previously known member stars in the Tucana III core, we identify 22 members in the tidal tails.We observe strong evidence for a velocity gradient of 8.0 0.4 km s-1 deg-1 over at least 3° on the sky. Based on the continuity in velocity, we confirm that the Tucana III tails are real tidal extensions of Tucana III. The large velocity gradient of the stream implies that Tucana III is likely on a radial orbit. We successfully obtain metallicities for four members in the core and 12 members in the tails. We find that members close to the ends of the stream tend to be more metal-poor than members in the core, indicating a possible metallicity gradient between the center of the progenitor halo and its edge. The spread in metallicity suggests that the progenitor of the Tucana III stream is likely a dwarf galaxy rather than a star cluster. Furthermore, we find that with the precise photometry of the Dark Energy Survey data, there is a discernible color offset between metal-rich disk stars and metal-poor stream members. This metallicity-dependent color offers a more efficient method to recognize metal-poor targets and will increase the selection efficiency of stream members for future spectroscopic follow-up programs on stellar streams. |
publishDate |
2018 |
dc.date.issued.fl_str_mv |
2018 |
dc.date.accessioned.fl_str_mv |
2019-01-18T02:31:25Z |
dc.type.driver.fl_str_mv |
Estrangeiro info:eu-repo/semantics/article |
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info:eu-repo/semantics/publishedVersion |
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article |
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http://hdl.handle.net/10183/187864 |
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0004-637X |
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001083049 |
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http://hdl.handle.net/10183/187864 |
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eng |
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eng |
dc.relation.ispartof.pt_BR.fl_str_mv |
The astrophysical journal. Bristol. Vol. 866, no. 1 (Oct. 2018), 22, 23 p. |
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info:eu-repo/semantics/openAccess |
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openAccess |
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