University of Oulu

J Romero-Gómez, Reynier F Peletier, J A L Aguerri, Steffen Mieske, Nicholas Scott, Joss Bland-Hawthorn, Julia J Bryant, Scott M Croom, F Sara Eftekhari, Jesús Falcón-Barroso, Michael Hilker, Glenn van de Ven, Aku Venhola, The SAMI–Fornax Dwarfs Survey – III. Evolution of [α/Fe] in dwarfs, from Galaxy Clusters to the Local Group, Monthly Notices of the Royal Astronomical Society, Volume 522, Issue 1, June 2023, Pages 130–150,

The SAMI–Fornax dwarfs survey : III. evolution of [α/Fe] in dwarfs, from galaxy clusters to the local group

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Author: Romero-Gómez, J1,2; Peletier, Reynier F3; Aguerri, J A L1,2;
Organizations: 1Instituto de Astrofísica de Canarias, Calle Vía Láctea S/N, E-38205 La Laguna, Tenerife, Spain
2Universidad de La Laguna Avda. Astrofísico Fco. Sánchez, E-38205 La Laguna, Tenerife, Spain
3Kapteyn Institute, University of Groningen, Landleven 12, NL-9747, AD, Groningen, the Netherlands
4European Southern Observatory, Alonso de Cordova 3107, 7630355 Vitacura, Santiago, Chile
5Sydney Institute for Astronomy, School of Physics, A28, The University of Sydney, NSW, 2006, Australia
6ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), Sydney, NSW 2006, Australia
7ESO, European Southern Observatory, Karl-Schwarzschild-Str 2, D-85748 Garching bei München, Germany
8Department of Astrophysics, University Vienna, Türkenschanzstrasse 17, A-1180 Wien, Austria
9Space Physics and Astronomy Research Unit, University of Oulu, Pentti Kaiteran katu 1, FI-90014 Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 3.6 MB)
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Language: English
Published: Oxford University Press, 2023
Publish Date: 2023-09-29


Using very deep, high spectral resolution data from the SAMI Integral Field Spectrograph, we study the stellar population properties of a sample of dwarf galaxies in the Fornax Cluster, down to a stellar mass of 10⁷ M⊙, which has never been done outside the Local Group. We use full spectral fitting to obtain stellar population parameters. Adding massive galaxies from the ATLAS3D project, which we re-analysed, and the satellite galaxies of the Milky Way, we obtained a galaxy sample that covers the stellar mass range 10⁴–10¹² M⊙. Using this large range, we find that the mass–metallicity relation is not linear. We also find that the [α/Fe]-stellar mass relation of the full sample shows a U-shape, with a minimum in [α/Fe] for masses between 10⁹ and 10¹⁰ M⊙. The relation between [α/Fe] and stellar mass can be understood in the following way: when the faintest galaxies enter the cluster environment, a rapid burst of star formation is induced, after which the gas content is blown away by various quenching mechanisms. This fast star formation causes high [α/Fe] values, like in the Galactic halo. More massive galaxies will manage to keep their gas longer and form several bursts of star formation, with lower [α/Fe] as a result. For massive galaxies, stellar populations are regulated by internal processes, leading to [α/Fe] increasing with mass. We confirm this model by showing that [α/Fe] correlates with clustercentric distance in three nearby clusters and also in the halo of the Milky Way.

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Series: Monthly notices of the Royal Astronomical Society
ISSN: 0035-8711
ISSN-E: 1365-8711
ISSN-L: 0035-8711
Volume: 522
Issue: 1
Pages: 130 - 150
DOI: 10.1093/mnras/stad953
Type of Publication: A1 Journal article – refereed
Field of Science: 115 Astronomy and space science
Funding: This research has been supported by the Spanish Ministry of Education, Culture and Sports under grant AYA2017-83204-P. The Sydney-AAO Multi-object Integral field spectrograph (SAMI) was developed jointly by the University of Sydney and the Australian Astronomical Observatory. Parts of this research were supported by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. Glenn van de Ven acknowledges funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme under grant agreement No. 724857 (Consolidator Grant ArcheoDyn). Reynier F. Peletier acknowledges the financial support from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 721463 to the SUNDIAL ITN network. Jesus Falcon-Barroso acknowledges support through the RAVET project by the grant PID2019-107427GB-C32 from the Spanish Ministry of Science, Innovation and Universities (MCIU), and through the IAC project TRACES which is partially supported through the state budget and the regional budget of the Consejeria de Economia, Industria, Comercio y Conocimiento of the Canary Islands Autonomous Community. For the analysis, we have used python; matplotlib (Hunter 2007), a suite of open source python modules that provide a framework for creating scientific plots; and astropy, a community-developed core python package for Astronomy (Astropy Collaboration 2013).
EU Grant Number: (721463) SUNDIAL - SUrvey Network for Deep Imaging Analysis and Learning
Copyright information: This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2023 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.