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

TL;DR

This survey provides detailed optical integral field spectroscopic data of 37 low-redshift 3C radio galaxies, revealing extensive emission line regions and complex gas kinematics, and explores the relationship between radio morphology and ionized gas properties.

Contribution

The paper completes the MURALES survey by presenting the final observations and analysis of 37 3C radio galaxies, highlighting the connection between radio morphology and emission line characteristics.

Findings

Most galaxies show extended emission line regions up to 80 kpc.

Ordered gas rotation observed in 25 galaxies.

FRII sources exhibit larger and more complex ionized gas structures.

Abstract

We present the final observations of a complete sample of 37 radio galaxies from the Third Cambridge Catalog (3C) with redshift <0.3 and declination <20 degrees obtained with the VLT/MUSE optical integral field spectrograph. These data were obtained as part of the MURALES survey (a MUse RAdio Loud Emission line Snapshot 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 such an 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 FRI sources the line emission region is generally compact, only a few kpc in size, and only in one case it exceeds the size of the host. Conversely, all but two of the FRII 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 FRII sources of high and low gas excitation. We confirm that the previous optical identification of 3C258 is incorrect: this radio source is likely associated with a QSO at z~ 1.54.