New Velocity Measurements of NGC 5128 Globular Clusters Out to 130 kpc: Outer Halo Kinematics, Substructure, and Dynamics
We present new radial velocity measurements from the Magellan and the Anglo-Australian Telescopes for 175 previously known and 121 newly confirmed globular clusters (GCs) around NGC 5128, the nearest accessible massive early-type galaxy at D = 3.8 Mpc. Remarkably, 28 of these newly confirmed GCs are...
| Main Authors: | , , , , , , , , , , , , , |
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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/acbf43 |
| _version_ | 1827827785238839296 |
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| author | Allison K. Hughes David J. Sand Anil Seth Jay Strader Chris Lidman Karina Voggel Antoine Dumont Denija Crnojević Mario Mateo Nelson Caldwell Duncan A. Forbes Sarah Pearson Puragra Guhathakurta Elisa Toloba |
| author_facet | Allison K. Hughes David J. Sand Anil Seth Jay Strader Chris Lidman Karina Voggel Antoine Dumont Denija Crnojević Mario Mateo Nelson Caldwell Duncan A. Forbes Sarah Pearson Puragra Guhathakurta Elisa Toloba |
| author_sort | Allison K. Hughes |
| collection | DOAJ |
| description | We present new radial velocity measurements from the Magellan and the Anglo-Australian Telescopes for 175 previously known and 121 newly confirmed globular clusters (GCs) around NGC 5128, the nearest accessible massive early-type galaxy at D = 3.8 Mpc. Remarkably, 28 of these newly confirmed GCs are at projected radii $\gt 50^{\prime} $ (≳54 kpc), extending to ∼130 kpc, in the outer halo where few GCs had been confirmed in previous work. We identify several subsets of GCs that spatially trace halo substructures that are visible in red giant branch star maps of the galaxy. In some cases, these subsets of GCs are kinematically cold, and may be directly associated with and originate from these specific stellar substructures. From a combined kinematic sample of 645 GCs, we see evidence for coherent rotation at all radii, with a higher rotation amplitude for the metal-rich GC subpopulation. Using the tracer mass estimator, we measure a total enclosed mass of 2.5 ± 0.3 × 10 ^12 M _⊙ within ∼120 kpc, an estimate that will be sharpened with forthcoming dynamical modeling. The combined power of stellar mapping and GC kinematics makes NGC 5128 an ongoing keystone for understanding galaxy assembly at mass scales inaccessible in the Local Group. |
| first_indexed | 2024-03-12T03:36:25Z |
| format | Article |
| id | doaj.art-22a364779e8045d0a133bd5274a1dc3c |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T03:36:25Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-22a364779e8045d0a133bd5274a1dc3c2023-09-03T13:08:56ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-0194713410.3847/1538-4357/acbf43New Velocity Measurements of NGC 5128 Globular Clusters Out to 130 kpc: Outer Halo Kinematics, Substructure, and DynamicsAllison K. Hughes0https://orcid.org/0000-0002-1718-0402David J. Sand1https://orcid.org/0000-0003-4102-380XAnil Seth2https://orcid.org/0000-0003-0248-5470Jay Strader3https://orcid.org/0000-0002-1468-9668Chris Lidman4https://orcid.org/0000-0003-1731-0497Karina Voggel5https://orcid.org/0000-0001-6215-0950Antoine Dumont6https://orcid.org/0000-0003-0234-3376Denija Crnojević7https://orcid.org/0000-0002-1763-4128Mario Mateo8https://orcid.org/0000-0002-3856-232XNelson Caldwell9https://orcid.org/0000-0003-2352-3202Duncan A. Forbes10https://orcid.org/0000-0001-5590-5518Sarah Pearson11https://orcid.org/0000-0003-0256-5446Puragra Guhathakurta12https://orcid.org/0000-0001-8867-4234Elisa Toloba13https://orcid.org/0000-0001-6443-5570Steward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ, 85721, USA ; akhughes@email.arizona.eduSteward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ, 85721, USA ; akhughes@email.arizona.eduDepartment of Physics & Astronomy, University of Utah , Salt Lake City, UT, 84112, USACenter for Data Intensive and Time Domain Astronomy, Department of Physics and Astronomy, Michigan State University , East Lansing, MI, 48824, USACentre for Gravitational Astrophysics, College of Science, The Australian National University , ACT 2601, Australia; The Research School of Astronomy and Astrophysics, Australian National University , ACT 2601, AustraliaUniversite de Strasbourg , CNRS, Observatoire Astronomique de Strasbourg, UMR 7550, F-67000 Strasbourg, FranceDepartment of Physics & Astronomy, University of Utah , Salt Lake City, UT, 84112, USAUniversity of Tampa , 401 West Kennedy Boulevard, Tampa, FL, 33606, USADepartment of Astronomy, University of Michigan , Ann Arbor, MI, 48109, USACenter for Astrophysics , Harvard & Smithsonian, 60 Garden Street, Cambridge, MA, 02138, USACentre for Astrophysics and Supercomputing, Swinburne University of Technology , Hawthorn VIC 3122, AustraliaCenter for Cosmology and Particle Physics, Department of Physics, New York University , 726 Broadway, New York, NY, 10003, USAUCO/Lick Observatory, University of California Santa Cruz , 1156 High Street, Santa Cruz, CA, 95064, USADepartment of Physics, University of the Pacific , 3601 Pacific Avenue, Stockton, CA, 95211, USAWe present new radial velocity measurements from the Magellan and the Anglo-Australian Telescopes for 175 previously known and 121 newly confirmed globular clusters (GCs) around NGC 5128, the nearest accessible massive early-type galaxy at D = 3.8 Mpc. Remarkably, 28 of these newly confirmed GCs are at projected radii $\gt 50^{\prime} $ (≳54 kpc), extending to ∼130 kpc, in the outer halo where few GCs had been confirmed in previous work. We identify several subsets of GCs that spatially trace halo substructures that are visible in red giant branch star maps of the galaxy. In some cases, these subsets of GCs are kinematically cold, and may be directly associated with and originate from these specific stellar substructures. From a combined kinematic sample of 645 GCs, we see evidence for coherent rotation at all radii, with a higher rotation amplitude for the metal-rich GC subpopulation. Using the tracer mass estimator, we measure a total enclosed mass of 2.5 ± 0.3 × 10 ^12 M _⊙ within ∼120 kpc, an estimate that will be sharpened with forthcoming dynamical modeling. The combined power of stellar mapping and GC kinematics makes NGC 5128 an ongoing keystone for understanding galaxy assembly at mass scales inaccessible in the Local Group.https://doi.org/10.3847/1538-4357/acbf43Globular star clustersRadial velocityGalaxy stellar halosGalaxy massesCatalogs |
| spellingShingle | Allison K. Hughes David J. Sand Anil Seth Jay Strader Chris Lidman Karina Voggel Antoine Dumont Denija Crnojević Mario Mateo Nelson Caldwell Duncan A. Forbes Sarah Pearson Puragra Guhathakurta Elisa Toloba New Velocity Measurements of NGC 5128 Globular Clusters Out to 130 kpc: Outer Halo Kinematics, Substructure, and Dynamics The Astrophysical Journal Globular star clusters Radial velocity Galaxy stellar halos Galaxy masses Catalogs |
| title | New Velocity Measurements of NGC 5128 Globular Clusters Out to 130 kpc: Outer Halo Kinematics, Substructure, and Dynamics |
| title_full | New Velocity Measurements of NGC 5128 Globular Clusters Out to 130 kpc: Outer Halo Kinematics, Substructure, and Dynamics |
| title_fullStr | New Velocity Measurements of NGC 5128 Globular Clusters Out to 130 kpc: Outer Halo Kinematics, Substructure, and Dynamics |
| title_full_unstemmed | New Velocity Measurements of NGC 5128 Globular Clusters Out to 130 kpc: Outer Halo Kinematics, Substructure, and Dynamics |
| title_short | New Velocity Measurements of NGC 5128 Globular Clusters Out to 130 kpc: Outer Halo Kinematics, Substructure, and Dynamics |
| title_sort | new velocity measurements of ngc 5128 globular clusters out to 130 kpc outer halo kinematics substructure and dynamics |
| topic | Globular star clusters Radial velocity Galaxy stellar halos Galaxy masses Catalogs |
| url | https://doi.org/10.3847/1538-4357/acbf43 |
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