A4 Refereed article in a conference publication
Survey of Planetary Nebulae in the Andromeda galaxy (M 31)
Authors: Bhattacharya, Souradeep; Arnaboldi, Magda; Gerhard, Ortwin; Caldwell, Nelson; Kobayashi, Chiaki; Hammer, Francois; Yang, Yanbin; Freeman, Kenneth C.; Hartke, Johanna; McConnachie, Alan
Editors: De Marco, Orsola; Zijlstra, Albert; Szczerba, Ryszard
Conference name: Symposium of the International Astronomical Union
Publication year: 2025
Journal: Proceedings of the International Astronomical Union
Book title : Planetary Nebulae : A Universal Toolbox in the Era of Precision Astrophysics
Series title: IAU Symposium
Volume: 19
Issue: 384
First page : 21
Last page: 30
ISSN: 1743-9213
eISSN: 1743-9221
DOI: https://doi.org/10.1017/S174392132400022X
Publication's open availability at the time of reporting: No Open Access
Publication channel's open availability : Partially Open Access publication channel
Web address : https://doi.org/10.1017/S174392132400022X
We summarize the main results from the survey of Planetary Nebulae (PNe) in M 31 with Megacam@CFHT and subsequent spectroscopy with Hectospec@MMT. We identified ∼5000 PNe in M 31 (∼1200 with spectroscopy; ∼200 with chemical abundances). We find a PN Luminosity Function faint-end rise, linked to a percentage of older stars in the parent population. We utilize PN extinction to distinguish young and old PNe. We find that the [Ar/H] vs [O/Ar] plane for emission-line nebulae is analogous to the [Fe/H] vs [α/Fe] plane for stars, and exploration of the M 31 disc PNe in this plane allowed us to constrain its chemical enrichment history. We find the kinematically and chemically distinct thin and thick discs of M 31, and that the G1-clump substructure is formed from perturbed disc material. We infer that M 31 has had a wet major (mass-ratio∼1:5) merger ∼2.5-4 Gyr ago, and obtain important constraints on the cannibalized satellite properties.
Funding information in the publication:
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.
