Spectroscopic Identifications of SWIRE sources in ELAIS-N1

TL;DR

This study provides extensive spectroscopic data for SWIRE sources in ELAIS-N1, confirming photometric redshift accuracy and classifying sources into different galaxy types, including hyperluminous quasars and AGN.

Contribution

It offers the largest spectroscopic follow-up in ELAIS-N1, validating photometric redshifts and applying emission line diagnostics for galaxy classification.

Findings

Good agreement between spectroscopic and photometric redshifts.

Identification of six hyperluminous infrared quasars as broad line AGN.

Emission line diagnostics align with SED and mid-IR classification methods.

Abstract

We present the largest spectroscopic follow-up performed in SWIRE ELAIS-N1. We were able to determine redshifts for 289 extragalactic sources. The values of spectroscopic redshifts of the latter have been compared with the estimated values from our photometric redshift code with very good agreement between the two for both galaxies and quasars. Six of the quasars are hyperluminous infrared galaxies all of which are broad line AGN. We have performed emission line diagnostics for 30 sources in order to classify them into star-forming, Seyferts, composite and LINER and compare the results to the predictions from our SED template fitting methods and mid-IR selection methods.