Dual Directional Expansion of Classical Cepheids in the Small Magellanic Cloud Revealed by Gaia Data Release 3
We present the three-dimensional kinematics of classical Cepheids (CCs) in the Small Magellanic Cloud (SMC) using Gaia DR3 data. By crossmatching the CCs obtained from the fourth phase of the Optical Gravitational Lensing Experiment with Gaia DR3, we obtain distances and proper motions (PMs) for 423...
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IOP Publishing
2025-01-01
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| Series: | The Astrophysical Journal Letters |
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| Online Access: | https://doi.org/10.3847/2041-8213/adce0b |
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| author | Satoya Nakano Kengo Tachihara |
| author_facet | Satoya Nakano Kengo Tachihara |
| author_sort | Satoya Nakano |
| collection | DOAJ |
| description | We present the three-dimensional kinematics of classical Cepheids (CCs) in the Small Magellanic Cloud (SMC) using Gaia DR3 data. By crossmatching the CCs obtained from the fourth phase of the Optical Gravitational Lensing Experiment with Gaia DR3, we obtain distances and proper motions (PMs) for 4236 CCs. Among them, radial velocities (RVs) are available for 91 stars, measured by Gaia, enabling the construction of an accurate relationship between distance and RV. Furthermore, we calculate the internal PMs of the CCs, providing the internal dynamics of the SMC while removing the distance projection effects. The CCs exhibit a northeast–southwest distance gradient, with internal PMs pointing northeast for nearer stars and southwest for more distant stars, indicating a northeast–southwest elongation. The RVs of the CCs show a northwest–southeast gradient, consistent with RVs of other stellar populations, and suggesting that the SMC’s northwest–southeast elongation results from interactions with the Large Magellanic Cloud. The distances and RVs of the CCs are nearly uncorrelated, implying that the two elongations arise from distinct causes. |
| format | Article |
| id | doaj-art-22e721fb3c4449789abb6623d20be4e7 |
| institution | OA Journals |
| issn | 2041-8205 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
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| series | The Astrophysical Journal Letters |
| spelling | doaj-art-22e721fb3c4449789abb6623d20be4e72025-08-20T02:30:59ZengIOP PublishingThe Astrophysical Journal Letters2041-82052025-01-019851L510.3847/2041-8213/adce0bDual Directional Expansion of Classical Cepheids in the Small Magellanic Cloud Revealed by Gaia Data Release 3Satoya Nakano0https://orcid.org/0009-0001-8036-7296Kengo Tachihara1https://orcid.org/0000-0002-1411-5410Department of Physics, Graduate School of Science, Nagoya University , Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan ; nasatoya@a.phys.nagoya-u.ac.jpDepartment of Physics, Graduate School of Science, Nagoya University , Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan ; nasatoya@a.phys.nagoya-u.ac.jpWe present the three-dimensional kinematics of classical Cepheids (CCs) in the Small Magellanic Cloud (SMC) using Gaia DR3 data. By crossmatching the CCs obtained from the fourth phase of the Optical Gravitational Lensing Experiment with Gaia DR3, we obtain distances and proper motions (PMs) for 4236 CCs. Among them, radial velocities (RVs) are available for 91 stars, measured by Gaia, enabling the construction of an accurate relationship between distance and RV. Furthermore, we calculate the internal PMs of the CCs, providing the internal dynamics of the SMC while removing the distance projection effects. The CCs exhibit a northeast–southwest distance gradient, with internal PMs pointing northeast for nearer stars and southwest for more distant stars, indicating a northeast–southwest elongation. The RVs of the CCs show a northwest–southeast gradient, consistent with RVs of other stellar populations, and suggesting that the SMC’s northwest–southeast elongation results from interactions with the Large Magellanic Cloud. The distances and RVs of the CCs are nearly uncorrelated, implying that the two elongations arise from distinct causes.https://doi.org/10.3847/2041-8213/adce0bCepheid distanceSmall Magellanic CloudGalaxy interactionsProper motionsRadial velocityGaia |
| spellingShingle | Satoya Nakano Kengo Tachihara Dual Directional Expansion of Classical Cepheids in the Small Magellanic Cloud Revealed by Gaia Data Release 3 The Astrophysical Journal Letters Cepheid distance Small Magellanic Cloud Galaxy interactions Proper motions Radial velocity Gaia |
| title | Dual Directional Expansion of Classical Cepheids in the Small Magellanic Cloud Revealed by Gaia Data Release 3 |
| title_full | Dual Directional Expansion of Classical Cepheids in the Small Magellanic Cloud Revealed by Gaia Data Release 3 |
| title_fullStr | Dual Directional Expansion of Classical Cepheids in the Small Magellanic Cloud Revealed by Gaia Data Release 3 |
| title_full_unstemmed | Dual Directional Expansion of Classical Cepheids in the Small Magellanic Cloud Revealed by Gaia Data Release 3 |
| title_short | Dual Directional Expansion of Classical Cepheids in the Small Magellanic Cloud Revealed by Gaia Data Release 3 |
| title_sort | dual directional expansion of classical cepheids in the small magellanic cloud revealed by gaia data release 3 |
| topic | Cepheid distance Small Magellanic Cloud Galaxy interactions Proper motions Radial velocity Gaia |
| url | https://doi.org/10.3847/2041-8213/adce0b |
| work_keys_str_mv | AT satoyanakano dualdirectionalexpansionofclassicalcepheidsinthesmallmagellaniccloudrevealedbygaiadatarelease3 AT kengotachihara dualdirectionalexpansionofclassicalcepheidsinthesmallmagellaniccloudrevealedbygaiadatarelease3 |