An extended halo around an ancient dwarf galaxy
© 2021, The Author(s), under exclusive licence to Springer Nature Limited. The Milky Way is surrounded by dozens of ultrafaint (<105 L☉) dwarf satellite galaxies1–3. They are the remnants of the earliest galaxies4, as confirmed by their ancient5 and chemically primitive6,7 stars. Simulations8–10...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Springer Science and Business Media LLC
2022
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| Online Access: | https://hdl.handle.net/1721.1/141805 |
| _version_ | 1810985299237404672 |
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| author | Chiti, Anirudh Frebel, Anna Simon, Joshua D Erkal, Denis Chang, Laura J Necib, Lina Ji, Alexander P Jerjen, Helmut Kim, Dongwon Norris, John E |
| author_facet | Chiti, Anirudh Frebel, Anna Simon, Joshua D Erkal, Denis Chang, Laura J Necib, Lina Ji, Alexander P Jerjen, Helmut Kim, Dongwon Norris, John E |
| author_sort | Chiti, Anirudh |
| collection | MIT |
| description | © 2021, The Author(s), under exclusive licence to Springer Nature Limited. The Milky Way is surrounded by dozens of ultrafaint (<105 L☉) dwarf satellite galaxies1–3. They are the remnants of the earliest galaxies4, as confirmed by their ancient5 and chemically primitive6,7 stars. Simulations8–10 suggest that these systems formed within extended dark matter halos and experienced early galaxy mergers and feedback. However, the signatures of these events would lie outside their core regions11, where spectroscopic studies are challenging12. Here we identify members of the Tucana II ultrafaint dwarf galaxy out to nine half-light radii, demonstrating the system to be markedly more spatially extended and chemically primitive than previously found. The distant stars in this galaxy are, on average, extremely metal poor (≲1/1000 of the solar iron abundance), affirming Tucana II as the most metal-poor known galaxy. We observationally establish an extended dark matter halo surrounding an ultrafaint dwarf galaxy out to 1 kpc, with a total mass of >107 M☉, consistent with a generalized Navarro–Frenk–White density profile. The extended nature of Tucana II suggests that it may have undergone strong bursty feedback or been the product of an early galactic merger10,11. We demonstrate that spatially extended stellar populations in ultrafaint dwarf galaxies13,14 are observable, opening up the possibility for detailed studies of the stellar halos of relic galaxies. |
| first_indexed | 2024-09-23T11:16:07Z |
| format | Article |
| id | mit-1721.1/141805 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T11:16:07Z |
| publishDate | 2022 |
| publisher | Springer Science and Business Media LLC |
| record_format | dspace |
| spelling | mit-1721.1/1418052022-04-09T03:28:32Z An extended halo around an ancient dwarf galaxy Chiti, Anirudh Frebel, Anna Simon, Joshua D Erkal, Denis Chang, Laura J Necib, Lina Ji, Alexander P Jerjen, Helmut Kim, Dongwon Norris, John E © 2021, The Author(s), under exclusive licence to Springer Nature Limited. The Milky Way is surrounded by dozens of ultrafaint (<105 L☉) dwarf satellite galaxies1–3. They are the remnants of the earliest galaxies4, as confirmed by their ancient5 and chemically primitive6,7 stars. Simulations8–10 suggest that these systems formed within extended dark matter halos and experienced early galaxy mergers and feedback. However, the signatures of these events would lie outside their core regions11, where spectroscopic studies are challenging12. Here we identify members of the Tucana II ultrafaint dwarf galaxy out to nine half-light radii, demonstrating the system to be markedly more spatially extended and chemically primitive than previously found. The distant stars in this galaxy are, on average, extremely metal poor (≲1/1000 of the solar iron abundance), affirming Tucana II as the most metal-poor known galaxy. We observationally establish an extended dark matter halo surrounding an ultrafaint dwarf galaxy out to 1 kpc, with a total mass of >107 M☉, consistent with a generalized Navarro–Frenk–White density profile. The extended nature of Tucana II suggests that it may have undergone strong bursty feedback or been the product of an early galactic merger10,11. We demonstrate that spatially extended stellar populations in ultrafaint dwarf galaxies13,14 are observable, opening up the possibility for detailed studies of the stellar halos of relic galaxies. 2022-04-08T15:23:04Z 2022-04-08T15:23:04Z 2021 2022-04-08T15:00:30Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/141805 Chiti, Anirudh, Frebel, Anna, Simon, Joshua D, Erkal, Denis, Chang, Laura J et al. 2021. "An extended halo around an ancient dwarf galaxy." Nature Astronomy, 5 (4). en 10.1038/S41550-020-01285-W Nature Astronomy Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf Springer Science and Business Media LLC arXiv |
| spellingShingle | Chiti, Anirudh Frebel, Anna Simon, Joshua D Erkal, Denis Chang, Laura J Necib, Lina Ji, Alexander P Jerjen, Helmut Kim, Dongwon Norris, John E An extended halo around an ancient dwarf galaxy |
| title | An extended halo around an ancient dwarf galaxy |
| title_full | An extended halo around an ancient dwarf galaxy |
| title_fullStr | An extended halo around an ancient dwarf galaxy |
| title_full_unstemmed | An extended halo around an ancient dwarf galaxy |
| title_short | An extended halo around an ancient dwarf galaxy |
| title_sort | extended halo around an ancient dwarf galaxy |
| url | https://hdl.handle.net/1721.1/141805 |
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