SINGG first light image: HIPASS J2334-36 = IC5332
Extragalactic
star formation surveys are almost always based on samples selected by
stellar luminosity. Hence, they are biased towards the galaxies that
are the brightest in the optical, ultraviolet, or far-infrared, and
biased against low luminosity and low surface brighhtness galaxies, and
these may hide a cosmologically significant amount of star formation.
We therefore have commenced a survey based on a sample that is free of
this stellar bias: the HI-selected galaxies from the
HIPASS survey. Since an interstellar medium is a prerequisite for
star formation, our survey will uniformly sample all galaxies that could
form stars, and hence provide an unbiased view of the local star
formation demographics. SINGG is an official
NOAO
Survey Program to image 500 HIPASS
galaxies in H
and the stellar continuum using the
CTIO 1.5m
telescope. This sample will yield a highly reliable measurement of the
local star formation rate density, and will provide a benchmark to
estimate biases in other H
samples. The HI content of galaxies,
combined with the star formation rate, will then be used to predict the
evolution of the HI mass function and the epoch when the cosmic gas tank
runs dry. This sample will simultaneously provide HII region luminosity
functions and images of the star formation morphology over a wide range
of galaxies. In particular, it will include dwarf irregulars which are
often missed in other studies. These data will be used to study global
star formation as a function of galaxy properties for a huge variety of
galaxies. During the next decade, SINGG will thus become the reference
H
dataset for galaxies in the local universe.