
%0 Journal Article
%A Valls-Gabaud, David 
%T Cosmological Applications of Halpha Surveys
%J Publications of the Astronomical Society of Australia
%D 1998/04/01
%V 15
%N 1
%P 111-117
%K 
%R https://doi.org/10.1071/AS98111
%U https://www.publish.csiro.au/paper/AS98111 
%X We briefly review three main applications of Halpha surveys in cosmology, namely: (1) the diffuse Halpha emission as a tracer of the free-free foreground that contaminates the fluctuations in the cosmic microwave background radiation; (2) the Halpha emission from galaxies as a measure of the formation rate of massive stars, both at low and high redshift; and (3) the diffuse Halpha emission from ionised clouds as a constraint on the local ionising background radiation. 
