TTF survey of galaxy populations

Abstract

The TAURUS Tunable Filter (TTF) affords a new approach to observational cosmology, allowing a wide field (10 arcmin) to be imaged monochromatically in contiguous wavelength intervals (6 - 60 Angstrom bandpass) over the R and I bands. In a 200 s exposure at the AAT, the TTF can detect H-alpha emission powered by star formation rates as low as 0.1 solar mass per year at z = 0.08 and 1 solar mass per year at z = 0.24 in 2 arcsec seeing (cf. 0.26 solar mass per year for the LMC). In this paper we describe an emission-line survey currently underway using the TTF on the AAT to detect redshifted H-alpha over the ranges z = 0.06 - 0.1 and z = 0.22 - 0.26. Such detections will be of timely interest to the Southern HI Sky Survey which is motivated along similar lines.