The Fornax3D project: Tracing the assembly history of the cluster from the kinematic and line-strength maps

¹ INAF–Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80131 Napoli, Italy
e-mail: enrichetta.iodice@inaf.it
² Armagh Observatory and Planetarium, College Hill, Armagh, BT61 9DG UK
³ European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei Muenchen, Germany
⁴ Ludwig Maximilian Universitaet, Professor-Huber-Platz 2, 80539 München, Germany
⁵ INAF–Osservatorio Astronomico di Brera, via Brera 28, 20128 Milano, Italy
⁶ Dipartimento di Fisica e Astronomia “G. Galilei”, Università di Padova, vicolo dell’Osservatorio 3, 35122 Padova, Italy
⁷ INAF–Osservatorio Astronomico di Padova, vicolo dell’Osservatorio 5, 35122 Padova, Italy
⁸ Department of Astrophysics, University of Vienna, Tuerkenschanzstrasse 17, 1180 Vienna, Austria
⁹ Sterrewacht Leiden, Leiden University, Postbus 9513 2300 RA Leiden, The Netherlands
¹⁰ Max-Planck-Institut fuer extraterrestrische Physik, Giessenbachstrasse, 85741 Garching bei Muenchen, Germany
¹¹ Instituto de Astrofísica de Canarias, Calle Vía Láctea s/n, 38200 La Laguna, Spain
¹² Departamento de Astrofísica, Universidad de La Laguna, Calle Astrofísico Francisco Sánchez s/n, 38205 La Laguna, Spain
¹³ University of California Observatories, 1156 High Street, Santa Cruz, CA 95064, USA
¹⁴ Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, 69117 Heidelberg, Germany
¹⁵ Department of Physics and Astronomy, Macquarie University, Sydney, NSW 2109, Australia
¹⁶ Australian Astronomical Observatory, PO Box 915 Sydney, NSW 1670, Australia
¹⁷ Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield AL10 9AB, UK
¹⁸ Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281, 9000 Gent, Belgium

Received: 17 April 2019
Accepted: 13 June 2019

Abstract

The 31 brightest galaxies (m_B ≤ 15 mag) inside the virial radius of the Fornax cluster were observed from the centres to the outskirts with the Multi Unit Spectroscopic Explorer on the Very Large Telescope. These observations provide detailed high-resolution maps of the line-of-sight kinematics, line strengths of the stars, ionised gas reaching 2–3 R_e for 21 early-type galaxies, and 1–2 R_e for 10 late-type galaxies. The majority of the galaxies are regular rotators, with eight hosting a kinematically distinct core. Only two galaxies are slow rotators. The mean age, total metallicity, and [Mg/Fe] abundance ratio in the bright central region inside 0.5 R_e and in the galaxy outskirts are presented. Extended emission-line gas is detected in 13 galaxies, most of them are late-type objects with wide-spread star formation. The measured structural properties are analysed in relation to the galaxies’ position in the projected phase space of the cluster. This shows that the Fornax cluster appears to consist of three main groups of galaxies inside the virial radius: the old core; a clump of galaxies, which is aligned with the local large-scale structure and was accreted soon after the formation of the core; and a group of galaxies that fell in more recently.