B3 Vertaisarvioimaton artikkeli konferenssijulkaisussa
The Andromeda Galaxy’s Last Major Merger: Constraints from the survey of Planetary Nebulae
Tekijät: Bhattacharya, Souradeep; Arnaboldi, Magda; Gerhard, Ortwin; Caldwell, Nelson; Kobayashi, Chiaki; Hammer, Francois; Yang, Yanbin; Freeman, Kenneth C.; Hartke, Johanna; McConnachie, Alan
Toimittaja: Tabatabaei, Fatemeh; Barbuy, Beatriz; Ting, Yuan-Sen
Konferenssin vakiintunut nimi: Symposium of the International Astronomical Union
Kustantaja: Cambridge University Press (CUP)
Julkaisuvuosi: 2024
Lehti: Proceedings of the International Astronomical Union
Kokoomateoksen nimi: Early Disk-Galaxy Formation from JWST to the Milky Way
Vuosikerta: 18
Aloitussivu: 123
Lopetussivu: 126
ISSN: 1743-9213
eISSN: 1743-9221
DOI: https://doi.org/10.1017/S1743921323000996
Julkaisun avoimuus kirjaamishetkellä: Ei avoimesti saatavilla
Julkaisukanavan avoimuus : Osittain avoin julkaisukanava
Verkko-osoite: https://doi.org/10.1017/s1743921323000996
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) ∼ 2.5-4.5 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.
Julkaisussa olevat rahoitustiedot:
SB is funded by the INSPIRE Faculty award (DST/INSPIRE/04/2020/002224), Department of Science and Technology (DST), Government of India. SB acknowledges support from the IMPRS on Astrophysics at the LMU Munich during his PhD.
