The Star Formation Across Cosmic Time (SFACT) Survey. III. Spectroscopy of the Initial Catalog of Emission-Line Objects

TL;DR

The SFACT survey uses narrowband imaging and follow-up spectroscopy to identify and analyze emission-line galaxies and QSOs across various redshifts, providing a valuable dataset for understanding galaxy evolution.

Contribution

This paper presents the spectroscopic data and methodology for the initial catalog of emission-line objects from the SFACT survey, enabling detailed analysis of galaxy properties across cosmic time.

Findings

415 confirmed emission-line galaxies in the pilot fields

Spectroscopic confirmation of faint sources (r ~ 25)

Emission-line diagnostic diagrams to classify galaxy types

Abstract

The Star Formation Across Cosmic Time (SFACT) survey is a new narrowband survey designed to detect emission-line galaxies (ELGs) and quasi-stellar objects (QSOs) over a wide range of redshifts in discrete redshift windows. The survey utilizes the WIYN 3.5m telescope and the Hydra multifiber positioner to perform efficient follow-up spectroscopy on galaxies identified in the imaging part of the survey. Since the objects in the SFACT survey are selected by their strong emission lines, it is possible to obtain useful spectra for even the faintest of our sources (r ~ 25). Here we present the 453 objects that have spectroscopic data from the three SFACT pilot-study fields, 415 of which are confirmed ELGs. The methodology for processing and measuring these data is outlined in this paper and example spectra are displayed for each of the three primary emission lines used to detect objects in the survey (H-alpha, [O III]5007, and [O II]3727). Spectra of additional QSOs and non-primary emission-line detections are also shown as examples. The redshift distribution of the pilot-study sample is examined and the ELGs are placed in different emission-line diagnostic diagrams in order to distinguish the star-forming galaxies from the active galactic nuclei.