The MURALES survey

III. Completing the MUSE observations of 37 3C low-z radio galaxies

¹ INAF – Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese, Italy
e-mail: barbara.balmaverde@inaf.it
² Dipartimento di Fisica e Astronomia, Università di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy
³ INAF – Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy
⁴ Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21210, USA
⁵ Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
⁶ INAF – Istituto di Radioastronomia, Via Gobetti 101, 40129 Bologna, Italy
⁷ INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Gobetti 93/3, 40129 Bologna, Italy
⁸ Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
⁹ Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands
¹⁰ Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USA
¹¹ University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
¹² SETI Institute, 189 N. Bernado Ave, Mountain View CA, 94043, USA
¹³ Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile

Received: 29 July 2020
Accepted: 30 September 2020

Abstract

We present the final observations of a complete sample of 37 radio galaxies from the Third Cambridge Catalogue (3C) with redshift < 0.3 and declination < 20° obtained with the VLT/MUSE optical integral field spectrograph. These data were obtained as part of the MUse RAdio Loud Emission line Snapshot (MURALES) survey with the main goal of exploring the AGN feedback process in the most powerful radio sources. We present the data analysis and, for each source, the resulting emission line images and the 2D gas velocity field. Thanks to the unprecedented depth these observations reveal emission line regions (ELRs) extending several tens of kiloparsec in most objects. The gas velocity shows ordered rotation in 25 galaxies, but in several sources it is highly complex. We find that the 3C sources show a connection between radio morphology and emission line properties. In the ten FR I sources the line emission region is generally compact, only a few kpc in size; only in one case does it exceed the size of the host. Conversely, all but two of the FR II galaxies show large-scale structures of ionized gas. The median extent is 16 kpc with the maximum reaching a size of ∼80 kpc. There are no apparent differences in extent or strength between the ELR properties of the FR II sources of high and low gas excitation. We confirm that the previous optical identification of 3C 258 is incorrect: this radio source is likely associated with a quasi-stellar object at z ∼ 1.54.