The Star Formation Across Cosmic Time (SFACT) Survey. I. Survey Description and Early Results from a New Narrow-Band Emission-Line Galaxy Survey

TL;DR

The SFACT survey uses narrow-band imaging on the WIYN telescope to detect emission-line galaxies across a wide redshift range, providing valuable data on star formation and AGN evolution over cosmic time.

Contribution

This paper introduces the SFACT survey, a novel narrow-band imaging approach with deep sensitivity and multiple filters, enabling detection of ELGs over a broad redshift range and initial analysis of its early results.

Findings

533 ELG candidates identified in 1.50 sq. degrees

Detection of key emission lines up to redshift 1.015

Survey depth reaches r = 25.0 magnitude

Abstract

We introduce the Star Formation Across Cosmic Time (SFACT) survey. SFACT is a new narrow-band survey for emission-line galaxies (ELGs) and QSOs being carried out using the wide-field imager on the WIYN 3.5 m telescope. Because of the superior depth and excellent image quality afforded by WIYN, we routinely detect ELGs to r = 25.0. Our survey observations are made using three custom narrow-band filters centered on 6590 A, 6950 A, and 7460 A. Due to the sensitivity of the survey, we are able to simultaneously detect sources via a number of different emission lines over a wide range of redshifts. The principal lines detected in SFACT are H-alpha (redshifts up to 0.144), [O III]5007 (redshifts up to 0.500) and [O II]3727 (redshifts up to 1.015). In this paper we detail the properties of the survey as well as present initial results obtained by analyzing our three pilot-study fields. These fields have yielded a total of 533 ELG candidates in an area of 1.50 square degrees (surface density of 355 ELGs per square degree). Follow-up spectra for a subset of the ELG candidates are also presented. One of the key attributes of the SFACT survey is that the ELGs are detected in discrete redshift windows that will allow us to robustly quantify the properties of the star-forming and AGN populations as a function of redshift to z = 1 and beyond. The planned acquisition of additional narrow-band filters will allow us to expand our survey to substantially higher redshifts.