The SAMI-Fornax Dwarfs Survey I: sample, observations, and the specific stellar angular momentum of dwarf elliptical galaxies

Author(s)
Nicholas Scott, F. Sara Eftekhari, Reynier F. Peletier, Julia J. Bryant, Joss Bland-Hawthorn, Massimo Capaccioli, Scott M. Croom, Michael Drinkwater, Jésus Falcón-Barroso, Michael Hilker, Enrichetta Iodice, Nuria F. P. Lorente, Steffen Mieske, Marilena Spavone, Glenn van de Ven, Aku Venhola
Abstract

Dwarf ellipticals are the most common galaxy type in cluster environments; however, the challenges associated with their observation mean that their formation mechanisms are still poorly understood. To address this, we present deep integral field observations of a sample of 31 low-mass (107.5 < M⋆ < 109.5 M☉) early-type galaxies in the Fornax cluster with the SAMI instrument. For 21 galaxies, our observations are sufficiently deep to construct spatially resolved maps of the stellar velocity and velocity dispersion - for the remaining galaxies, we extract global velocities and dispersions from aperture spectra only. From the kinematic maps, we measure the specific stellar angular momentum λR of the lowest mass dE galaxies to date. Combining our observations with early-type galaxy data from the literature spanning a large range in stellar mass, we find that λR decreases towards lower stellar mass, with a corresponding increase in the proportion of slowly rotating galaxies in this regime. The decrease of λR with mass in our sample dE galaxies is consistent with a similar trend seen in somewhat more massive spiral galaxies from the CALIFA survey. This suggests that the degree of dynamical heating required to produce dEs from low-mass starforming progenitors may be relatively modest and consistent with a broad range of formation mechanisms.

Organisation(s)
Department of Astrophysics
External organisation(s)
The University of Sydney, University of Groningen, Università degli studi di Napoli Federico II, University of Queensland, Institute of Astrophysics of the Canary Islands, European Southern Observatory (Germany), INAF Astronomical Observatory of Capodimonte , Macquarie University, European Southern Observatory (Chile), University of Oulu
Journal
Monthly Notices of the Royal Astronomical Society
Volume
497
Pages
1571-1582
No. of pages
12
ISSN
0035-8711
DOI
https://doi.org/10.1093/mnras/staa2042
Publication date
09-2020
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy, 103004 Astrophysics
Keywords
ASJC Scopus subject areas
Astronomy and Astrophysics, Space and Planetary Science
Portal url
https://ucrisportal.univie.ac.at/en/publications/fb9874cc-b4c4-412d-932c-77ea1b2e0396