The Andromeda Galaxy's Last Major Merger: Constraints from the survey of Planetary Nebulae
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2023
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866929241414696960 |
|---|---|
| author | Bhattacharya, Souradeep Arnaboldi, Magda Gerhard, Ortwin Caldwell, Nelson Kobayashi, Chiaki Hammer, Francois Yang, Yanbin Freeman, Kenneth C. Hartke, Johanna McConnachie, Alan |
| author_facet | Bhattacharya, Souradeep Arnaboldi, Magda Gerhard, Ortwin Caldwell, Nelson Kobayashi, Chiaki Hammer, Francois Yang, Yanbin Freeman, Kenneth C. Hartke, Johanna McConnachie, Alan |
| contents | The Andromeda galaxy (M 31) has experienced a tumultuous merger history as evidenced by the many substructures present in its inner halo. We use planetary nebulae (PNe) as chemodynamic tracers to shed light on the recent merger history of M 31. We identify the older dynamically hotter thicker disc in M 31 and a distinct younger dynamically colder thin disc. The two discs are also chemically distinct with the PN chemodynamics implying their formation in a `wet' major merger (mass ratio ~1:5) ~2.5-4 Gyr ago. From comparison of PN line-of-sight velocities in the inner halo substructures with predictions of a major-merger model in M 31, we find that the same merger event that formed the M 31 thick and thin disc is also responsible for forming these substructures. We thereby obtain constraints on the recent formation history of M 31 and the properties of its cannibalized satellite. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2305_02761 |
| institution | arXiv |
| publishDate | 2023 |
| record_format | arxiv |
| spellingShingle | The Andromeda Galaxy's Last Major Merger: Constraints from the survey of Planetary Nebulae Bhattacharya, Souradeep Arnaboldi, Magda Gerhard, Ortwin Caldwell, Nelson Kobayashi, Chiaki Hammer, Francois Yang, Yanbin Freeman, Kenneth C. Hartke, Johanna McConnachie, Alan Astrophysics of Galaxies Solar and Stellar Astrophysics The Andromeda galaxy (M 31) has experienced a tumultuous merger history as evidenced by the many substructures present in its inner halo. We use planetary nebulae (PNe) as chemodynamic tracers to shed light on the recent merger history of M 31. We identify the older dynamically hotter thicker disc in M 31 and a distinct younger dynamically colder thin disc. The two discs are also chemically distinct with the PN chemodynamics implying their formation in a `wet' major merger (mass ratio ~1:5) ~2.5-4 Gyr ago. From comparison of PN line-of-sight velocities in the inner halo substructures with predictions of a major-merger model in M 31, we find that the same merger event that formed the M 31 thick and thin disc is also responsible for forming these substructures. We thereby obtain constraints on the recent formation history of M 31 and the properties of its cannibalized satellite. |
| title | The Andromeda Galaxy's Last Major Merger: Constraints from the survey of Planetary Nebulae |
| topic | Astrophysics of Galaxies Solar and Stellar Astrophysics |
| url | https://arxiv.org/abs/2305.02761 |