University of Oulu

F Sara Eftekhari and others, The SAMI–Fornax Dwarfs Survey – II. The Stellar Mass Fundamental Plane and the dark matter fraction of dwarf galaxies, Monthly Notices of the Royal Astronomical Society, Volume 517, Issue 4, December 2022, Pages 4714–4735,

The SAMI–Fornax Dwarfs Survey : II. The Stellar Mass Fundamental Plane and the dark matter fraction of dwarf galaxies

Saved in:
Author: Eftekhari, F Sara1; Peletier, Reynier F1; Scott, Nicholas2,3;
Organizations: 1Kapteyn Institute, University of Groningen, Landleven 12, 9747, AD, Groningen, the Netherlands
2Sydney Institute for Astronomy, School of Physics, A28, The University of Sydney, NSW 2006, Australia
3ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), Sydney, NSW 2006, Australia
4European Southern Observatory, Alonso de Cordova 3107, 7630355 Vitacura, Santiago, Chile
5INAF Osservatorio Astronomico di Teramo, via Maggini, I-64100, Teramo, Italy
6School of Mathematics and Physics, The University of Queensland, Brisbane, QLD 4072, Australia
7Instituto de Astrofísica de Canarias, Calle Vía Láctea s/n, E-38205 La Laguna, Tenerife, Spain
8Departamento de Astrofísica, Universidad de La Laguna (ULL), E-38206 La Laguna, Tenerife, Spain
9ESO, European Southern Observatory, Karl-Schwarzschild-Str 2, D-85748 Garching bei München, Germany
10INAF - Astronomical Observatory of Capodimonte, via Moiariello 16, I-80131 Napoli, Italy
11Department of Astrophysics, University Vienna, Türkenschanzstrasse 17, A-1180 Wien, Austria
12Space 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, 3.3 MB)
Persistent link:
Language: English
Published: Oxford University Press, 2022
Publish Date: 2023-06-28


We explore the kinematic scaling relations of 38 dwarf galaxies in the Fornax Cluster using observations from the SAMI integral field spectrograph. We focus on the Fundamental Plane (FP), defined by the physical properties of the objects (scale length, surface brightness, and velocity dispersion) and the Stellar Mass (Fundamental) Plane, where surface brightness is replaced by stellar mass, and investigate their dynamical-to-stellar-mass ratio. We confirm earlier results that the Fornax dEs are significantly offset above the FP defined by massive, hot stellar systems. For the Stellar Mass (Fundamental) Plane, which shows much lower scatter, we find that young and old dwarf galaxies lie at about the same distance from the plane, all with comparable scatter. We introduce the perpendicular deviation of dwarf galaxies from the Stellar Mass Plane defined by giant early-types as a robust estimate of their DM fraction, and find that the faintest dwarfs are systematically offset above the plane, implying that they have a higher dark matter fraction. This result is confirmed when estimating the dynamical mass of our dEs using a virial mass estimator, tracing the onset of dark matter domination in low mass stellar systems. We find that the position of our galaxies on the Stellar Mass FP agrees with the galaxies in the Local Group. This seems to imply that the processes determining the position of dwarf galaxies on the FP depend on the environment in the same way, whether the galaxy is situated in the Local Group or in the Fornax Cluster.

see all

Series: Monthly notices of the Royal Astronomical Society
ISSN: 0035-8711
ISSN-E: 1365-8711
ISSN-L: 0035-8711
Volume: 517
Issue: 4
Pages: 4714 - 4735
DOI: 10.1093/mnras/stac2606
Type of Publication: A1 Journal article – refereed
Field of Science: 115 Astronomy and space science
Copyright information: © The Author(s) 2022. Published by Oxford University Press on behalf of Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.