Discovery of the Magellanic Stellar Stream Out to 100 kpc
The Magellanic Stream (MS)—an enormous ribbon of gas spanning 140° of the southern sky trailing the Magellanic Clouds—has been exquisitely mapped in the five decades since its discovery. However, despite concerted efforts, no stellar counterpart to the MS has been conclusively identified. This stell...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/acf7bf |
| _version_ | 1827794018058108928 |
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| author | Vedant Chandra Rohan P. Naidu Charlie Conroy Ana Bonaca Dennis Zaritsky Phillip A. Cargile Nelson Caldwell Benjamin D. Johnson Jiwon Jesse Han Yuan-Sen Ting |
| author_facet | Vedant Chandra Rohan P. Naidu Charlie Conroy Ana Bonaca Dennis Zaritsky Phillip A. Cargile Nelson Caldwell Benjamin D. Johnson Jiwon Jesse Han Yuan-Sen Ting |
| author_sort | Vedant Chandra |
| collection | DOAJ |
| description | The Magellanic Stream (MS)—an enormous ribbon of gas spanning 140° of the southern sky trailing the Magellanic Clouds—has been exquisitely mapped in the five decades since its discovery. However, despite concerted efforts, no stellar counterpart to the MS has been conclusively identified. This stellar stream would reveal the distance and 6D kinematics of the MS, constraining its formation and the past orbital history of the Clouds. We have been conducting a spectroscopic survey of the most distant and luminous red giant stars in the Galactic outskirts. From this data set, we have discovered a prominent population of 13 stars matching the extreme angular momentum of the Clouds, spanning up to 100° along the MS at distances of 60–120 kpc. Furthermore, these kinematically selected stars lie along an [ α /Fe]-deficient track in chemical space from −2.5 < [Fe/H] <− 0.5, consistent with their formation in the Clouds themselves. We identify these stars as high-confidence members of the Magellanic Stellar Stream. Half of these stars are metal-rich and closely follow the gaseous MS, whereas the other half are more scattered and metal-poor. We argue that the metal-rich stream is the recently formed tidal counterpart to the MS, and we speculate that the metal-poor population was thrown out of the SMC outskirts during an earlier interaction between the Clouds. The Magellanic Stellar Stream provides a strong set of constraints—distances, 6D kinematics, and birth locations—that will guide future simulations toward unveiling the detailed history of the Clouds. |
| first_indexed | 2024-03-11T18:26:48Z |
| format | Article |
| id | doaj.art-406065d4e6ee41a68acf40933f76729c |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-11T18:26:48Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-406065d4e6ee41a68acf40933f76729c2023-10-13T16:17:06ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-01956211010.3847/1538-4357/acf7bfDiscovery of the Magellanic Stellar Stream Out to 100 kpcVedant Chandra0https://orcid.org/0000-0002-0572-8012Rohan P. Naidu1https://orcid.org/0000-0003-3997-5705Charlie Conroy2https://orcid.org/0000-0002-1590-8551Ana Bonaca3https://orcid.org/0000-0002-7846-9787Dennis Zaritsky4https://orcid.org/0000-0002-5177-727XPhillip A. Cargile5https://orcid.org/0000-0002-1617-8917Nelson Caldwell6https://orcid.org/0000-0003-2352-3202Benjamin D. Johnson7https://orcid.org/0000-0002-9280-7594Jiwon Jesse Han8https://orcid.org/0000-0002-6800-5778Yuan-Sen Ting9https://orcid.org/0000-0001-5082-9536Center for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA ; vedant.chandra@cfa.harvard.eduMIT Kavli Institute for Astrophysics and Space Research , 77 Massachusetts Avenue, Cambridge, MA 02139, USACenter for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA ; vedant.chandra@cfa.harvard.eduThe Observatories of the Carnegie Institution for Science , 813 Santa Barbara Street, Pasadena, CA 91101, USASteward Observatory and Department of Astronomy, University of Arizona , Tucson, AZ 85721, USACenter for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA ; vedant.chandra@cfa.harvard.eduCenter for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA ; vedant.chandra@cfa.harvard.eduCenter for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA ; vedant.chandra@cfa.harvard.eduCenter for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA ; vedant.chandra@cfa.harvard.eduResearch School of Astronomy & Astrophysics, Australian National University , Cotter Road, Weston, ACT 2611, Australia; School of Computing, Australian National University , Acton ACT 2601, Australia; Department of Astronomy, The Ohio State University , Columbus, OH 43210, USAThe Magellanic Stream (MS)—an enormous ribbon of gas spanning 140° of the southern sky trailing the Magellanic Clouds—has been exquisitely mapped in the five decades since its discovery. However, despite concerted efforts, no stellar counterpart to the MS has been conclusively identified. This stellar stream would reveal the distance and 6D kinematics of the MS, constraining its formation and the past orbital history of the Clouds. We have been conducting a spectroscopic survey of the most distant and luminous red giant stars in the Galactic outskirts. From this data set, we have discovered a prominent population of 13 stars matching the extreme angular momentum of the Clouds, spanning up to 100° along the MS at distances of 60–120 kpc. Furthermore, these kinematically selected stars lie along an [ α /Fe]-deficient track in chemical space from −2.5 < [Fe/H] <− 0.5, consistent with their formation in the Clouds themselves. We identify these stars as high-confidence members of the Magellanic Stellar Stream. Half of these stars are metal-rich and closely follow the gaseous MS, whereas the other half are more scattered and metal-poor. We argue that the metal-rich stream is the recently formed tidal counterpart to the MS, and we speculate that the metal-poor population was thrown out of the SMC outskirts during an earlier interaction between the Clouds. The Magellanic Stellar Stream provides a strong set of constraints—distances, 6D kinematics, and birth locations—that will guide future simulations toward unveiling the detailed history of the Clouds.https://doi.org/10.3847/1538-4357/acf7bfLarge Magellanic CloudMagellanic CloudsMagellanic StreamSmall Magellanic CloudStellar streams |
| spellingShingle | Vedant Chandra Rohan P. Naidu Charlie Conroy Ana Bonaca Dennis Zaritsky Phillip A. Cargile Nelson Caldwell Benjamin D. Johnson Jiwon Jesse Han Yuan-Sen Ting Discovery of the Magellanic Stellar Stream Out to 100 kpc The Astrophysical Journal Large Magellanic Cloud Magellanic Clouds Magellanic Stream Small Magellanic Cloud Stellar streams |
| title | Discovery of the Magellanic Stellar Stream Out to 100 kpc |
| title_full | Discovery of the Magellanic Stellar Stream Out to 100 kpc |
| title_fullStr | Discovery of the Magellanic Stellar Stream Out to 100 kpc |
| title_full_unstemmed | Discovery of the Magellanic Stellar Stream Out to 100 kpc |
| title_short | Discovery of the Magellanic Stellar Stream Out to 100 kpc |
| title_sort | discovery of the magellanic stellar stream out to 100 kpc |
| topic | Large Magellanic Cloud Magellanic Clouds Magellanic Stream Small Magellanic Cloud Stellar streams |
| url | https://doi.org/10.3847/1538-4357/acf7bf |
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