An optical spectroscopic survey of the 3CR sample of radio galaxies with z<0.3. I. Presentation of the data

TL;DR

This paper presents a comprehensive, uniform optical spectroscopic dataset for 113 low-redshift 3CR radio galaxies, enabling detailed analysis of their nuclear properties and active nuclei characteristics.

Contribution

It provides the first homogeneous, high-quality spectral atlas and diagnostic measurements for a complete sample of 3CR radio galaxies at z<0.3.

Findings

Spectral atlas of 113 radio galaxies presented

Identification of active nuclei with broad emission lines

Uniform measurements of key optical emission line ratios

Abstract

We present a homogeneous and 92 % complete dataset of optical nuclear spectra for the 113 3CR radio sources with redshifts < 0.3, obtained with the Telescopio Nazionale Galileo. For these sources we could obtain uniform and uninterrupted coverage of the key spectroscopic optical diagnostics. The observed sample, including powerful classical FR II radio-galaxies and FR I, together spanning four orders of magnitude in radio-luminosity, provides a broad representation of the spectroscopic properties of radio galaxies. In this first paper we present an atlas of the spectra obtained, provide measurements of the diagnostic emission line ratios, and identify active nuclei with broad line emission. These data will be used in follow-up papers to address the connection between the optical spectral characteristics and the multiwavelength properties of the sample.