Spectroscopic Cosmological Surveys in the Far-IR

TL;DR

This paper demonstrates the feasibility of using the SAFARI instrument onboard SPICA for spectroscopic cosmological surveys, showing it can effectively detect and analyze high-redshift galaxies and their activity types through simulations.

Contribution

It introduces simulation-based evidence that SAFARI can perform blind spectroscopy to study galaxy evolution up to z~3, highlighting its potential for high-redshift galaxy detection.

Findings

7-10 sources detected per 2'x2' field in multiple lines

Approximately 20% of detected sources are at z>2

SAFARI can distinguish between AGN and star formation activity

Abstract

We show the feasibility of spectroscopic cosmological surveys with the SAFARI instrument onboard of SPICA. The work is done through simulations that make use of both empirical methods, i.e. the use of observed luminosity functions and theoretical models for galaxy formation and evolution. The relations assumed between the line emission to trace AGN and star formation activity have been derived from the observations of local samples of galaxies. The results converge to indicate the use of blind spectroscopy with the SAFARI FTS at various resolutions to study galaxy evolution from the local to the distant (z~3) Universe. Specifically, two different and independent galaxy evolution models predict about 7-10 sources to be spectroscopically detected in more than one line in a 2'x 2'SAFARI field of view, down to the expected flux limits of SAFARI, with about 20% of sources to be detected at z>2. SPICA-SAFARI will be therefore excellent at detecting high-z sources and at assessing in a direct way their nature (e.g whether mainly AGN or Star Formation powered) thanks to blind spectroscopy.