The Effectiveness of Mid/Far IR Blind, Wide Area, Spectral Surveys in Breaking the Confusion Limit

¹ Cardiff University, School of Physics & Astronomy, Queens Buildings, The Parade, Cardiff, CF24 3AA, UK
² Physics Department, Imperial College London, Prince Consort Road, London SW7 2AZ, UK
³ Space Science and Technology Department, CCLRC Rutherford Appleton Laboratory, Didcot, Oxfordshire, OX11 0QX, UK
⁴ Department of Physics, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta, T1J 1B1, Canada

Abstract

Source confusion determines the useful depth to which to take large-area extragalactic surveys. 3D imaging spectrometers, with positional as well as spectral information, however, can potentially provide a means by which to break the traditional confusion limit.

In this poster we present the results of our investigation into the effectiveness of mid/far infrared, blind, wide area spectroscopic surveys with SAFARI in breaking through the confusion limit. We generate an artificial sky representative of 100 SAFARI footprints based on two galaxy evolution models: bright-end and burst-mode. Using a fully automated redshift determination method we find we can accurately estimate redshifts for 37 and 53% of sources with continuum fluxes that are as much as an order of magnitude below the traditional continuum confusion limit (at 120 μm) for the bright-end and burst-mode evolution models respectively. Our results suggest that deep, blind spectral line surveys with SAFARI will be able to break the traditional photometric confusion limit, allowing us to resolve a significant number of previously inaccessible galaxies, and so potentially to differentiate between different galaxy evolution models.