Red-channel (6000-8000 {\AA}) nuclear spectra of 376 local galaxies

TL;DR

This study presents new optical nuclear spectra for 376 local galaxies, classifies their nuclear activity types using emission line diagnostics, and provides the spectra in accessible online databases.

Contribution

It offers a substantial set of new spectral data for local galaxies and applies a consistent classification scheme to identify nuclear activity types.

Findings

164 spectra are newly obtained or previously unpublished.

Classified nuclei into Seyfert, strong/weak AGN, star-forming, retired, and passive categories.

Spectra are publicly available in CDS and NED databases.

Abstract

We obtained long-slit optical spectra of the nuclear regions of 376 galaxies in the local Universe using the 1.5m Cassini telescope of Bologna Observatory. Of these spectra, 164 were either never taken before by the Sloan Digital Sky Survey (SDSS), or given by the Nasa Extragalactic Database (NED). With these new spectra, we contribute investigating the occurrence of active galactic nuclei (AGNs). Nevertheless, we stress that the present sample is by no means complete, thus, it cannot be used to perform any demographic study. Following the method presented in Gavazzi et al. (2011), we classify the nuclear spectra using a six bin scheme: SEY (Seyfert), sAGN (strong AGN), and wAGN (weak AGN) represent active galactic nuclei of different levels of activity; HII accounts for star-forming nuclei; RET (retired) and PAS (passive) refer to nuclei with poor or no star-formation activity. The spectral classification is performed using the ratio of 6584 {\lambda} [NII] to H{\alpha} lines and the equivalent width (EW) of H{\alpha} versus [NII]/H{\alpha} (WHAN diagnostic introduced by Cid Fernandes and collaborators) after correcting H{\alpha} for underlying absorption. The obtained spectra are made available in machine readable format via the Strasbourg Astronomical Data Center (CDS) and NED.